Acknowledgements The authors are deeply indebted to several individuals who made important contributions to this report. First of all, I would like to thank Mr. Majid Al Mansour Al Mansouri and Dr. Jaber Al Jaberi for their initiative in calling for this study and their continual support throughout the effort. Dr El Waleed Mohamed Hamad El Malik was instrumental in facilitating the many meetings and assisting with the acquisition of needed databases and other information. There were many individuals who provided invaluable support in obtaining the data and information needed by the models used in the study. Dr. Mohamed Dawoud provided extensive water resource information on water supply and demand that helped in the assessment about the impact of climate change on water resources. Mr. Khaldoun Kiwan, Mr. Maher Kabshawi, and Mr. Mayas Qarqaz, specialists in the Terrestrial Environmental Research Centre were very helpful in helping me to understand the types of data and information available for assessing the impact of climate change on terrestrial ecosystems in Abu Dhabi. Mr. Abdessalaam Thabit provided an essential orientation to information on marine resources and the marine environment in the Abu Dhabi region. In a study where baseline information on coastal zones, water resources and dryland ecosystems played such a crucial role, Mark Sorensen, Joseph Abdo, Anil Kumar were instrumental in orientation and access to the Environmental Agency’s environmental database under the AGEDI framework. Rashed Mohammed Amin Karkain from Dubai and Nabil Alolaqi, Sultan Zaidi, and Rashed Alkaabi from the Abu Dhabi Environmental Agency provided excellent facilitation in arranging meetings.
Contributors
Author William W. Dougherty
Co-Authors Amanda Fencl, Balqis Osman Elasha, Chris Swartz, David Yates, Jeremy Fisher, Richard Klein
Address Stockholm Environment Institute - US Center An Independent Research Affiliate of Tufts University 11 Curtis Avenue Somerville, MA 02144 USA www.serinternational.org
Photographers Xavier Eichaker, Hanne &Jens Eriksen, Salim Javed, Gary Brown AND MARAYKA.
Copyright © 2009 Environmental Agency -Abu Dhabi.
All Rights Reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, electrostatic, magnetic tape, mechanical, photocopying, recording, scanning or otherwise, without permission in writing from the publisher.
ISBN 9789948-408-41-3
Design and prepared by Environment Agency-Abu Dhabi, P.O. Box 45553, Abu Dhabi, UAE Tel: +971-2-4454777; Fax: +971-2-4463339 Website: www.ead.ae
Produced from camera-ready-copy supplied by the publisher CLIMATE CHANGE Impacts, Vulnerability & Adaptation
Coastal Zones in the Water Resources Dryland Ecosystems United Arab Emirates in Abu Dhabi in Abu Dhabi
PO Box: 45553, Abu Dhabi, United Arab Emirates Tel:+971-2- 4454777; Fax:+971-2- 4463339 Website: www.ead.ae 4 Foreword
There are many levels at which the United Arab Emirates is concerned about climate change. The UAE is already subject to extreme climatic conditions that will likely become only more extreme due to climate change. Even small long-term variations in temperature and precipitation could have adverse effects on productive activities due to the fragile nature of the nation’s precious natural resources and interconnectivity with global economic activity. The key aim of this report is to identify and assess the potential magnitude of the physical impacts due to climate change on three vulnerable sectors in the UAE: coastal zones, water resources, and dryland ecosystems. Additionally, recommendations are suggested regarding sustainable adaptation processes for going forward after this preliminary assessment. This process first requires adjustments in policies, institutions and attitudes that establish enabling conditions, and second is accompanied by eventual technological and infrastructural changes.
There are three major parts of the report offering sector-specific key findings and recommendations as summarized below:
1. “Part 1: Impacts, Vulnerability, & Adaptation for Coastal Zones” in the United Arab Emirates, an analysis of sea level rise on coastal zones throughout the Emirates.
2. “Part 2: Impacts, Vulnerability, & Adaptation for Water Resources” in Abu Dhabi, an analysis of water supply and demand in the face of climate change in the Abu Dhabi Emirate.
3. “Part 3: Impacts, Vulnerability, & Adaptation for Dryland Ecosystems” in Abu Dhabi, a qualitative assessment of the impact of increased variability in rainfall and temperature regimes on dryland systems in the Abu Dhabi Emirate.
It is my hope that this effort paves the way for mainstreaming climate risks into tomorrow’s development efforts in the UAE.
Majid Al Mansouri Secretary-General Environment Agency-Abu Dhabi
5 Table of Contents (Part 1) Coastal Zones In the UAE
Page
List of Tables...... 12 List of Figures...... 12 List of Acronyms...... 13
1. Introduction...... 14
2. Sea-level rise impacts on coastal systems...... 17 2.1. Abrupt or rapid sea level rise...... 19 2.2. Eustatic sea level rise from deglaciation 20 2.3. Sea-surface temperatures, thermal expansion, and thermosteric sea level rise...... 21 2.4. Increase in the tidal variation around the mean...... 22 2.5. Storms frequency and intensity in relation to rising sea levels...... 23 2.6. Coastal erosion and shoreline retreat...... 27
3. Climate change and coastal ecosystems...... 28 3.1. Sabkhat coastal ecosystems...... 28 3.2. Mangroves...... 29 3.3. Sea grass...... 30 3.4. Coral Reefs...... 31 3.5. Influence of sea level rise and sea surface temperature warming on coastal fauna ...... 32
4. Inundation analysis of coastal areas ...... 34 4.1. Introduction ...... 34 4.2. Methodology ...... 34 4.3. Data limitations, methodological considerations: challenges to mapping sea level rise...... 37 4.4. Defining mean sea level for the UAE: reliance on tidal and elevation data...... 40 4.5. GIS and a flood-fill algorithm...... 41 4.6. Scenario development...... 42 4.7. Results and Discussion ...... 42 4.7.1. 2050: 1 meters above mean sea level...... 43 4.7.2. 12050: 3 meters above mean sea level (Accelerated ice cap melting)...... 43 4.7.3. 2100: 9 meters above mean sea level (Accelerated ice cap melting) ...... 48 4.8. Summary Tables...... 48
5. Framework for climate change adaptation in coastal areas ...... 50 5.1. Historical context for adaptation in coastal zones...... 50 5.2. Information Systems...... 51 5.3. Planning and Design 51 5.4. Planning for Adaptation: the UNDP Adaptation Policy Framework (APF)...... 53 5.5. Implementation ...... 54 5.6. Monitoring and evaluation ...... 54 5.7. Adaptation Strategies ...... 55
6. Conclusions and recommendations...... 57 7. List of references ...... 59 8. Glossary ...... 63 Annex 1: Elevation data sensitivity analysis ...... 67 Annex 2: Inundation maps...... 69
6 Climate Change Impacts, Vulnerability & Adaptation Table of Contents (Part 2) Water Resources In Abu Dhabi
Page
List of Tables ...... 76 List of Figures...... 76 List of Acronyms ...... 77
1. Introduction ...... 78
2. Current water stress and planned responses...... 80 2.1. Regional Supplies: West (including Liwa), East (Abu Dhabi City and Al Ain Oasis)...... 80 2.2. Demand Projections ...... 84 2.3. Irrigation Strategies ...... 85
3. Qualitative climate impact assessment of water resources...... 88
3.1. Global Climate Change ...... 88 3.2. Regional Climate Change ...... 91 3.3. Generating Climate Scenarios for the ADE ...... 93 3.4. Temperature Increase and diminished surface water reserves ...... 96 3.5. Increased monthly precipitation variability ...... 96 3.6. Rainfall variability and flash flooding...... 97 3.7. “Greening the desert”: a vision at risk ...... 98 3.8. Vulnerability of Irrigated Agriculture ...... 98 3.8.1. Groundwater over-pumping ...... 99 3.8.2. Salt buildup ...... 99 3.9. Uncertainty of climate impacts: a challenge to water planners ...... 100
4. Quantitative climate impact assessment of water resources ...... 102 4.1. The Water Evaluation and Planning (WEAP) model of Abu Dhabi Emirate ...... 102 4.2. Data requirements and acquisition ...... 104 4.3. Representing Water Demands and Supplies in WEAP ...... 104 4.4. Representing Irrigation Demands ...... 107 4.5. Calibration using observed data ...... 108 4.6. Scenarios and Key Assumptions: ...... 111 4.7. Developing Climate Change Scenarios ...... 111 4.8. Summary of Modeled Scenarios ...... 112 4.8.1. The Optimistic Scenarios (1, 1.1, and 1.2) ...... 114 4.8.2. The Pessimistic Scenarios (2, 2.1, and 2.2)...... 114 4.8.3. The Middle of the Road Scenarios (3) ...... 116 4.8.4. The Reference Scenario (3.1)...... 116
5. Results and discussion ...... 117
5.1. Water Demand ...... 117 5.2. Water Supply ...... 119 5.3. Groundwater Supplies ...... 121 5.4. Adaptation and Mitigation to Climate Change: Hand-in-Hand ...... 122
6. Conclusions ...... 124
7. References ...... 126
Annex 1: Data sources and key assumptions ...... 128
Annex 2: Climate projections ...... 134
7 Table of Contents (Part 3) Dryland Ecosystems in Abu Dhabi
Page
List of Tables ...... 143 List of Figures ...... 143 List of Acronyms ...... 143
1. Introduction ...... 144
2. Potential risks to dryland ecosystems ...... 145
3. Terrestrial ecosystems of the UAE ...... 146
4. Major terrestrial ecosystems in Abu Dhabi ...... 147 4.1. Coastal Zones ...... 147 4.2. Coastal and Inland Sabkhat ...... 147 4.3. Sand Sheets and Dunes ...... 148 4.4. Piedmont Alluvial and Interdunal Plains ...... 148 4.5. Mountains and Wadis ...... 148 4.6. Freshwater Habitats and Oases ...... 150 4.7. Urban Environments ...... 150
5. Important flora in Abu Dhabi...... 151 5.1. Mangroves ...... 151 5.2. Mountain and Jebel vegetation ...... 152 5.3. Wadi beds vegetation ...... 153 5.4. Flora of the oases ...... 154
6. Fauna of the terrestrial ecosystems in Abu Dhabi ...... 155 6.1 Birds ...... 155 6.2. Threatened bird species ...... 156 6.3. Mammals ...... 157 6.4. Reptiles ...... 157
7. Vulnerability assessment of drylands ecosystems ...... 158 7.1. Observed Climatic changes in dryland ecosystems ...... 158 7.2. Projected climatic changes in dry land ecosystems ...... 158 7.3. Current climate and expected climatic change in the UAE ...... 158 7.4. Vulnerability of terrestrial ecosystems of Abu Dhabi ...... 159 Overgrazing ...... 160 Desertification and land degradation...... 161 Other factors ...... 162
8. Biodiversity, ecosystem thresholds, and climate change...... 163 8.1. Biodiversity and ecological thresholds ...... 164 8.2. Implications of climate change on UAE dryland ecosystems ...... 168 8.3. Examples of climate change induced biodiversity thresholds in the UAE ...... 169 Avian migration and phenological change ...... 169 Transitions between shrubs, grasses, invasives, and desert in savanna ecosystems ...... 171 8.4. Adaptation to climate change in drylands ...... 172 Autonomous adaptation ...... 172 Autonomous adaptation by Fauna ...... 173 Planned Adaptation Strategies ...... 173
9. Modeling climate change impacts in the UAE ...... 176 9.1. Ecosystem models: limited understanding, limitless possibilities ...... 176 Empirical or first principles? Top-down versus bottom-up models...... 176 Model limitations ...... 177
8 Climate Change Impacts, Vulnerability & Adaptation Page
9.2. Types of ecosystem models ...... 177 First principles ecosystem models: potential vegetation and disturbance ...... 178 Bioclimatic envelope models ...... 178 Patch structure and spatial distribution models ...... 179 Climate / phenology models ...... 179 9.3. Examples of applied ecosystem models in arid environments ...... 180 Modeling for climate change impact assessment ...... 180 Modeling to understand vulnerabilities ...... 181 Modeling for adaptive management ...... 181 9.4. Next steps for modeling and data collection in the UAE ...... 181 Development of baseline datasets ...... 182 Development of essential environmental studies ...... 182
10. References ...... 183
Annex 1: Global vulnerable areas ...... 186
Annex 2: Expected effects of global warming on Asia ...... 187
Annex 3: Main urban settlements in dryland areas ...... 188
Annex 4: Main drivers of ecosystem change ...... 189 Annex 5: List of regular wintering and breeding
water birds in the United Arab Emirates ...... 190
Annex 6: Important flora of the UAE...... 194
Annex 7: Recorded mammalian taxa occurring in UAE ...... 196 Annex 8: Native species list of terrestrial
mammals of UAE ...... 197
9
11 List of Tables Page
Table 1‑1: Climate Change and Related Factors Relevant to Coasts ...... 15 Table 2‑1. Saffir-Simpson Hurricane Scale, FEMA ...... 25 Table 4‑1. Relative accuracy of LiDAR data ...... 39 Table 4‑2. Comparison of inundated areas using different elevation datasets ...... 40 Table 4‑3. UAE Coastal Cities ...... 43 2 Table 4‑4. ABU DHABI Zones of Inundation (km ) ...... 48 Table 4‑5. DUBAI Zones of Inundation (km2) ...... 48 Table 5‑1. Potential adaptation scenarios ...... 56
List of Figures Page
Figure 1-1. IPCC estimations of sea level rise by 2100 ...... 15 Figure 2-1. Estimates of the various contributions to global mean sea level change ...... 17 Figure 2-2. Variations in global mean sea level ...... 17 Figure 2-3. Map of policy-relevant tipping elements in the climate system, overlain on global population density ...... 18 Figure 2-4. How glacial melt raises sea levels ...... 20 Figure 2-5. Historical, cumulative contribution of deglaciation to sea levels ...... 20 Figure 2-6. Global sea level change due to thermal expansion for 1995 to 2003 ...... 21 Figure 2-7. Residual change in water level based on observed and predicted water levels ...... 22 Figure 2-8. Location of Safaniya and Ras Tanura ...... 23 Figure 2-9. Tropical Cyclone Gonu near the Middle East and southern Asia ...... 24 Figure 2-10. Area of stronger than normal northwesterly winds (Shamal)...... 24 Figure 2-11.Computer simulated distribution of storm surge heights at 4 different times 25 Figure 2-12. Map of Gonu’s path ...... 26 Figure 3-1. Coastal Sabkhas in Abu Dhabi ...... 28 Figure 3-2. Mangroves around Abu Dhabi, E.A data layer ...... 30 Figures 3-3. Kingfish abundance vs. SST ...... 32 Figure 4-1. Depictions of two main sea level rise modeling strategies ...... 34 Figure 4-2. Data displaying areas susceptible to sea level rise ...... 35 Figure 4-3. 1 meter scenario for Abu Dhabi, visualized in Google Earth ...... 36 Figure 4-4. CReSIS, 6m inundation ...... 37 Figure 4-5. Model of the Earth, approximating sea level and geoid ...... 38 Figure 4-6. Illustration of how the LIDAR sensing instrument captures elevation points ...... 39 Figure 4-7. Comparison of 30-meter USGS, 10-meter USGS, and 3-meter LiDAR data for US coast ...... 40 Figure 4-8. Example flood-fill process...... 41 Figure 4-9. Abu Dhabi Coastal Ecosystems, no SLR ...... 44 Figure 4-10. 1 meters above mean sea level by 2050 ...... 45 Figure 4-11. 3 meters above mean sea level (Accelerated ice cap melting / by 2050 ...... 46 Figure 4-12. 3 meters above mean sea level (Accelerated ice cap melting / by 2050 (Zoom view on Abu Dhabi)...... 47 Figure 4-13. 9 meters above mean sea level (Accelerated ice cap melting) by 2100...... 45 Figure 5-1. Types of Adaptation ...... 55 Figure A2-1 Baseline map, Abu Dhabi...... 69 Figure A2-2 1 meter sea level rise, Abu Dhabi...... 70 Figure A2-3 3 meters sea level rise, Abu Dhabi...... 71 Figure A2-4 9 meters sea level rise, Abu Dhabi (Infrastructure impacts)...... 72 Figure A2-5 9 meters sea level rise, Abu Dhabi (ecosystem impacts)...... 72 Figure A2-6 1,3,9 meters sea level rise, Dubai...... 73
12 Climate Change Impacts, Vulnerability & Adaptation & Adaptation for & List of Acronyms United Arab Emirates
APF Adaptation Policy Framework MHHW Mean higher high water AML Arc Macro Language mm millimeters CARA Consortium for Atlantic Regional MA Millennium Ecosystem Assessment Assessment mmsl monthly mean sea level
CO2 Carbon dioxide MSL mean sea level CReSIS Center for Remote Sensing of NAO North Atlantic Oscillation Ice Sheets NASA National Aeronautics and Space CSI Consortium for Spatial Administration (USA) Impacts, Vulnerability Information Coastal Zones in the NW Northwest DEM Digital elevation model PMSL Permanent Service for EGM Earth Gravitational Model Mean Sea Level ENSO El NiÑo Southern Oscillation RSL Relative sea level GCC Gulf Corporation Council SLR sea level rise GDP Gross domestic product SRES Special Report on Emissions GEF Global environment facility Scenarios GHG Green house gas (emissions) SRTM Shuttle Radar Topography GIS Geographical Information System Mission GLOBE Global Land One-km SST Sea-surface temperatures Base Elevation UAE United Arab Emirates GPS Global positioning system UK United Kingdom INS Inertial navigation systems UNFCCC United Nations Framework IPCC Intergovernmental Panel on Convention on Climate Change Climate Change USGS US Geological Service IPCC 4AR IPCC Fourth Assessment Report WAIS West Antarctic ice sheet IPCC SAR IPCC Second Assessment Report WGI Working Group I of the IPCC IPCC TAR (IPCC) Third Assessment Report WMO World Meteorological LiDAR Light Detection and Ranging Organization m meters
13 1. Introduction
The UAE has nearly 1,300 kilometers of established a National Environmental Action coastline. Approximately 85% of the population Plan for the Marine Environment that includes and over 90% of the infrastructure of the UAE strategies for the conservation of biodiversity, is located within several meters of sea level endangered species and habitats, protection in low-lying coastal areas (ERAS, 2005). The of the marine water quality and the marine UAE is fundamentally different than it was 30- environment, promotion of sustainable fisheries 40 years ago. Its rapid GDP growth, economic and environmental awareness in communities diversification and coastal tourism, present and schools, and improved oil spill and waste st new challenges for the 21 century. In the management responses (Federal Environment UAE, coastal areas are important and highly Agency, 2002). populated centers of industry, manufacturing, and commerce. Moreover, the coasts of the UAE Climate change also endangers coastal are home to multiple ecological subsystems ecosystems and developments. Climate (Alsharhan and El Sammak, 2004) and changes include increases in global sea level, important cultural heritage sites and artifacts sea water temperature, precipitation intensity, (Hellyer and Beech, 2000). atmospheric CO2, and changes in wave climate and runoff. Coastal communities may The UAE straddles the Tropic of Cancer and the start witnessing changes in storm frequency, Abu Dhabi emirate, in particular, is influenced by intensity, and movement. As the oceans warm, the direct sun its geographical position allows. rising sea-surface temperature will lead to The climate is hot and arid, yet on the coast, thermal expansion and changes in mean sea humidity can reach over 90 percent in summer level. Change in sea-surface temperatures could and autumn. Inland it is far less humid, although mean intensified coral bleaching, which affects the temperature is higher, often exceeding species’ reproduction and migration. 50ºC before midday in July. The Arabian Gulf coast is extremely shallow and gently sloping In 1996 and 1998, the UAE faced two catastrophic continental shelf. The littoral zone of the UAE coral bleaching and mortality events associated is characterized by active coastal sabkhas, or with seawater temperature anomalies. Wave salt flats. The UAE sabkhas of the UAE are conditions could change, risking altered patterns internationally recognized as the largest and of erosion and accretion (IPCC, 2007). Until now, most geomorphologically interesting of sabkha the effects of climate change induced sealevel in the world (Aspinall, n.d.). rise on coastal populations, infrastructure, and biology has yet to be adequately accounted for The coastal zone is threatened by numerous in planning activities within the UAE. Broad processes. Coastal areas are affected by climate change drivers and potential impacts reclamation, dredging or other usage including on coastal zones are summarized in Table 1‑1 oil-related activities; however, much of such from Klein and Nicholls (1999). development has been for recreational purposes. Population growth, urban sprawl, and expansion While it is important to consider all of the of coastal development and tourism have led potential climate change phenomena affecting to extensive reclaimed, dredged, and land- coastal zones, sea level rise appears to be filled areas, reduced wildlife populations, and particularly important due to the continued habitat loss of mangroves, coral reefs and sea and escalating concentration of population, grass. Additionally, coastal areas have suffered infrastructure, and industry in the coastal zones. from past oil spills and remediation techniques. A rise in mean sea level is one of the most certain Approximately 31% of the world production of consequences of global warming. As can be seen oil passes through the Strait of Hormuz each in Figure 1-1, the IPCC’s Fourth Assessment day impacting marine life from oil pollution Report (2007), posits an upper boundary for and thermal discharges. Numerous studies global sea-level rise by 2100 of 0.59 cm. However, have been done in these fields, specific to the the IPCC calculations don’t include ice-sheet UAE. Well aware of these issues, the UAE has dynamics. According to the IPCC, sea level rise
14 Climate Change Impacts, Vulnerability & Adaptation Table 1‑1. Climate Change and Related Factors Relevant to Coasts.
CLIMATE DIRECTION OF CHANGE POTENTIAL BIOGEOPHYSICAL EFFECTS FACTOR
Inundation and displacement of wetlands and lowlands; coastal erosion; increased storm Global sea level +ve flooding and damage; salinisation; rising water tables and impeded drainage.
Increased coral bleaching; increased algal
Sea water blooms; northerly migration of coastal species; Adaptation for &
+ve United Arab Emirates temperature decreased incidence of sea ice at higher latitudes
Precipitation +ve (in many parts of the world) Increased flood risk in coastal lowlands intensity
changed cross-shore and longshore sediment Wave climate Unknown transport, and hence patterns of erosion and accretion
Storm Changed occurrence of storm flooding and Regional variation frequency damage
Changed sediment supply from rivers to the Impacts, Vulnerability Run-off Regional variation Coastal Zones in the coast
Atmospheric +ve Increased productivity in coastal ecosystems CO2
Figure 1-1. IPCC (2007) estimations of sea level rise by 2100.
15 is expected to continue at a significant rate for in particular, to the impacts of sea level rise given centuries, even if climate forcing is stabilized its current socioeconomic conditions in coastal (IPCC, 2001). From a planning perspective, areas is quite significant. After accounting for it is important to acknowledge and accept future development and population increases that more than 10 meters of sea-level rise is in these areas, sea level rise poses important possible, depending on the emission scenario Emirate-wide policy questions regarding current considered, and albeit over a long time frame and future development plans and investment (IPCC, 2007). decisions. The Abu Dhabi Environment Agency published a “Marine and Coastal Environment In addition to the effects of sea level rise Sector Paper” in April 2006, which devotes on social and economic structures, the some attention to climate change, though the vulnerability of coastal ecosystems is also of treatment was brief relative to the magnitude particular concern. Ecosystems in the UAE of the threat. are particularly vulnerable, dominated by the intricate ecologies of coastal sabkha (salt- This analysis builds on existing work, with encrusted flats), mangrove wetlands, and areas substantial space devoted to both a qualitative that provide habitat for a wide variety of flora review of climate change impacts on the coastal and fauna. The most extensive system of tidal zone as well as a quantitative assessment of sea lagoons and creeks lies in the vicinity of Abu level rise on coastal areas, presented as a series Dhabi city behind the barrier island complex. of 2-dimensional maps indicating the extent Regionally, sea level rise is projected to result of coastal inundation. A sea level rise (SLR) in increased soil salinization, which will affect inventory of the coastal regions of the UAE is inland agriculture and forestry projects, as considered central to the assessment of the well as resolved in flooding in most of the Gulf vulnerability and potential adaptation to climate Corporation Council (GCC) coastal cities and change in the region and is a key component of towns (Brown, 2003). the study that follows.
The potential exposure of the UAE, Abu Dhabi
16 Climate Change Impacts, Vulnerability & Adaptation 2. Sea-level Rise Impacts on Coastal Systems
Coastal zones are one of the most vulnerable rise is possible, depending on the emission areas to climate change given the increased scenario and assumptions regarding ice-sheet certainty of a rise in mean sea level. As mentioned dynamics (IPCC, 2007). Figure 2-1 shows a earlier, the IPCC’s Fourth Assessment Report, breakdown of contributing factors to mean sea posits an upper boundary for global sea-level level rise. As the IPCC explains, the data in this
figure are for 1961 to 2003 (light blue) and 1993 Adaptation for & rise by 2100 of 0.59m. Beyond 2100, sea level United Arab Emirates rise projections are increasingly dependent to 2003 (dark blue). The bars represent a 90% on emissions scenarios (IPCC, 2007). Sea level error range. Sea level change is the sum of the changes are induced by both natural factors upper four entries (thermal expansion through Antarctica) in addition to the observed rate of such as changing ocean basin volume and rise. For the sum, the error has been calculated depth as the earth’s plates separate and collide as the square root of the sum of squared errors with each other, as well as deglaciation from of the contributions; to obtain the error for the anthropogenic global warming. difference, combine errors of the sum and the Taking a step back to clarify the terms used, observed rate (IPCC WGI, Chapter 5). mean sea level (MSL) is the average level of the Researcher Dr. Vivien Gornitz, jointly posted Impacts, Vulnerability sea’s surface, as measured relative to a fixed Coastal Zones in the at the Columbia University Center for Climate level on the land. MSL is typically calculated Systems Research and NASA’s Goddard over long periods, usually averaged over the 19 Institute for Space studies, explains global year lunar cycle as it smoothes tidal variations. trends further. She writes that 20th century There are seasonal or annual changes in MSL global sea level, according to tide gauge data, in addition to gradual increases in MSL that has been increasing by 1.7-1.8 mm/yr and that scientists have tracked over time. most of this rise is due to ocean warming and Deglaciation of continental ice caps, in mountain glaciers melting, which have receded particular, can change sea level by tens of dramatically in many places especially during meters (Emery and Aubrey, 1991). Deglaciation the last few decades. She continues, “since changes the volume of water in the ocean, 1993, an even higher sea level trend of about 2.8 which is known as a eustatic sea level change. mm/yr has been measured from the TOPEX/ The IPCC estimates, however, do not include POSEIDON satellite altimeter. Analysis of ice-sheet dynamics even though over a long longer tide-gauge records (1870-2004) also time frame, more than 10 meters of sea-level suggests possible late 20th century acceleration in global sea level” (Gornitz, 2007). Computed from satellite altimetry from January 1993 to October 2005, Figure 2‑2 captures these variations in global mean by plotting the
Figure 2-1. Estimates of the various contributions to global mean sea level change. Figure 2‑2. Variations in global mean sea level. Source: (IPCC, 2007) Source: (IPCC WGI, 2007)
17 18 Climate ChangeImpacts,Vulnerability &Adaptation
Figure 2‑3. Map of policy-relevant tipping elements in the climate system, overlain on global population density. Source: Lenton et al, 2008 differences in observed sea levels to the mean mean sea levels is much easier to adapt to than as averaged from 1993 to mid-2001. The dots the rapid sea level rise coastal cities may face. are 10-day estimates (from Topex/Poseidon Abrupt sea level rise is worrisome because it Satellite in Fed and Jason Satellite) in green happens on a time scale far quicker than most and the blue solid curve corresponds to 60-day societies are able to adapt. smoothing.
Sea levels are not rising uniformly around the Large, abrupt climatic changes with major world. Meehl et al. (2007) found that regional impacts are by no means new phenomena in the course of the planet’s history. While historically, sea-level change will depart significantly from Adaptation for & the global mean trends. Local (or relative) much of these abrupt changes have been due United Arab Emirates changes in sea level differ from global trends due to natural causes, most recently, scientists to regional variations in oceanic level change are concerned that human forcing of climate thermal expansion, geological uplift/subsidence, change is affecting the probability of abrupt sea-floor spreading, and the level of glaciation, change (Alley et al., 2003). Abrupt climate and relative sea level change that drives impacts change occurs when the climate system crosses and is of concern to coastal managers (Nicholls a threshold, triggering a transition to a new and Klein, 2005; Harvey, 2006a). Both sea level state. The rate of transition is determined by rise and coastal settlement patterns have the climate system, and will likely be faster than substantial inertia, and there is high confidence the cause of that transition. Rapid sea level Impacts, Vulnerability
that the unavoidability of sea level rise will Coastal Zones in the rise, for example, could result from crossing a continue to conflict with present and future temperature threshold, after which the planet human development patterns (IPCC, 2007). transitions from sea level, at its current status, Coastal areas experience more SLR than the to a new higher level. open ocean (IPCC, 2007). According to Short Kasperson et al. (2005) conducted a thorough and Neckles (1999), the direct effects of sea review of the risk of future rapid large sea- level rise on the coastal zones will be increased water depths, changes in tidal variation (both level rise (SLR). In their review, the potential mean tide level and tidal prism), altered water collapse of the West Antarctic ice sheet (WAIS) movement, and increased sea water intrusion was the primary driver of rapid SLR. Most inland. These effects should be quite noticeable consider rapid sea level rise of five to ten in the shallow Arabian Gulf. In the southern meters over the next several centuries to be a Gulf, studies have already examined sea level worst case scenario; the timing of which is also rise relative to historic shorelines (Evans et al., dependent on the rate of warming, ice sheet 1969, Taylor and Llling, 1969; Purser and Loreau, melts, and reaching one of several tipping 1973; Dalongeville et al., 1993; Lambeck, 1996; points in the other’s climate system yielding Kirkham, 1997). Others have examined sea level long-term consequences. A tipping point is a in relation to geology (Uchupi et al., 1999), or moment in time, at which a small change yields Gulf floor sedimentation (Stoffers and Ross, large, long-term consequences for the climate 1979; Sarnthein, 1972; Reynolds, 1993). About system. The map in Figure 2‑3 suggests policy- 80% of the monthly mean sea level variance can relevant elements with critical tipping points be related to seasonal changes (Sultan et al., in the climate system (Lenton et.al., 2008). Any 1995; IPCC, 2007). of these could plausibly be triggered in this century, and the main conclusion was that it will 2.1. Abrupt or rapid sea level rise be “characterized by potentially catastrophic Many researchers identify abrupt or rapid sea consequences and high epistemic uncertainty” level rise as a major problem facing coastal (Kasperson, 2005). As such, effective risk societies (Titus, 1988 and 1990; Mitchell, 1991). management demands adaptive management Characteristics of rapid sea level rise include regimes, vulnerability reduction, and urgent both elevation in the mean level of the ocean mitigation of climate change forces, such as the surface and increase in the tidal variation around production of anthropogenic greenhouse gas the mean (ADEA 2006). Gradual increase in emissions.
19 A noteworthy concern is that emissions abatement will not necessarily prevent ice sheets from collapsing; uncertainty remains on whether emissions reductions now may be too little or too late to reverse the trend of ice sheet melts. The policy importance of adequately planning for the worst case scenario will be discussed in greater detail in Section 5.
2.2. Eustatic sea level rise from deglaciation
The IPCC’s Fourth Assessment Report (2007) estimates of global sea-level rise by 2100 do not include ice-sheet dynamics, however the continued melt of certain glacial types will yield eustatic sea level rise, or rise corresponding to a change in ocean volume. Floating ice, like what is found in the Northern Polar regions will not affect sea level if it melts because when it melts it will displace and equivalent volume of water. Continental ice sheets, however, are more worrisome. According to marine geophysicist Robin Bell of Columbia University’s Earth Figure 2‑5. Historical, cumulative contribution of Institute, sea levels rise by about 1/16 inches for deglaciation to sea levels. Source (IPCC, 2007). every 150 cubic miles of ice that melts off one of the poles (Bell, 2008). Scientists are concerned et al. (2006), the primary driver of rapid SLR that the rate of glacial melt/ is far outstripping was the potential collapse of the WAIS. Rising the rate of snow accumulation This phenomenon global temperatures could trigger an irreversible and melt accumulate imbalance can be seen breakdown of ice sheets. visually in Figure 2‑4. If the WAIS were to disappear again, sea level Scientists hypothesize that during the previous would rise most 19 feet. Additionally, the ice interglacial period when the West Antarctic Ice in the Greenland ice sheet could add 24 feet Sheet (WAIS) collapsed; sea level was 6/meters to that, the East Antarctic ice sheet could add higher than at present (Emery and Aubrey, yet another 170 feet to the level of the world’s 1991). In both Kasperson et al. (2005) and Tol oceans, totaling more than 213 feet in all (Bell, 2008). In Figure 2-5 we see the cumulative contribution of continental glaciers and ice- caps to the sea-level rise since 1960, expressed Continental ice caps in mm (right axis) and grouped by major zone. For example, melting of Alaska glaciers have contributed to a rise in the world sea level by Snow Evaporation Decrease in ice roughly 6.5 mm since 1960 (IPCC, 2007). volume raises sea level Glacial melt is directly related to ambient air New sea level temperature and warming trends; a global temperature rise of 2-5°C could destabilize Greenland irreversibly. Even though such a an temperature rise lies within the range of several future climate projections for the 21st century, Figure 2-4. How glacial melt raises sea levels any significant meltdown would take many in the context of the water cycle. centuries.
20 Climate Change Impacts, Vulnerability & Adaptation 20 approach has been followed in the UK (Pearson
15 et al., 2005; Thorne et al., 2006), its application
) elsewhere is limited to date. 10 5 2.3. Sea-surface temperatures, 0 thermal expansion, and el Change (mm -5 thermosteric sea level rise
Sea Lev Sea -10
Thermosteric sea level rise is the component Adaptation for & -15 United Arab Emirates of the total sea level that results from thermal -20 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 expansion of ocean waters, (the term steric is Year used when both thermal expansion and salinity Figure 2‑6. Global sea level change due to effects are considered) (Berge-Nguyen et al., thermal expansion for 1995 to 2003 Source: 2008). Thus sea-surface temperatures (SST) IPCC, 2007. play a vital role in coastal dynamics with respect to the interplay between temperature and sea Climate stabilization could mitigate ice sheet levels. Dissolved salt content also influences breakdown, but sea level rise due to thermal how oceans react to warming such that there expansion remains likely. Gornitz (2007) are regional differences and delays in thermal Impacts, Vulnerability cautions against ignoring ice-sheet dynamics expansion depending on a body of water’s Coastal Zones in the and notes the alarming changes that satellites particular salinity properties. have detected. Parts of the Greenland Ice Sheet Sea surface temperature changes the density at lower elevations are thinning, and glaciers and thus volume of the oceans. The heat capacity are rapidly disgorging ice into the ocean, of the ocean is so large there will be a delay adding 0.23 to 0.57 mm/yr to the sea within the before the full effects of any global warming are last decade. Ice loss by glaciers in Greenland evident. Warming atmospheric temperatures doubled between 1996 and 2005 (NASA, 2006). will continue to cause sea levels to rise far Small changes in glacial mass balance whether after any global greenhouse gas emissions and through accumulation from precipitation, subsequent temperature stabilization scheme ablation from evaporation, or the production are reached. Any warming of the ocean, leads and melt of ice bergs are influential in the global to an expansions of ocean volume and thus an increase in mean sea level (Pugh, 2004; IPCC, sea level budget. There remains, however, a great 2007; Hassanzadeh et al., 2007). deal of uncertainty in the specific contribution of the mass balance of Greenland and Antarctic Globally, the IPCC satellite altimetry time series ice sheets (Pugh, 2004). show an overall trend of increasing heat content in the world oceans, allowing for some inter- The global mean sea level rise scenarios are annual and inter-decadal variations. Near-global based on thermal expansion and ice melt; the ocean temperature data for the last 50 years best estimate shows an acceleration of up to 2.4 has recently been made available, allowing for times compared to the 20th century (see Meehl the first observationally-based estimate of the et al., 2007). For the IPCC A1B scenario, the thermal expansion contribution to sea level rise spatial standard deviation by the 2080's is 0.08 in past decades. For the most recent years, the meters (m), with a larger rise than average in best estimates of the land-ice contribution to the Arctic. While there is currently insufficient sea level are available from various observations understanding to develop detailed scenarios, of glaciers, ice caps and ice sheets. Hulme et al. (2002) suggested that impact Relying on these data sets, the Fourth analysis should explore additional sea-level Assessment Report (IPCC, 2007) estimates that rise scenarios of +50% the amount of global thermal expansion will contribute more than mean rise, plus uplift/subsidence, to assess the half of the average sea level rise; increases in full range of possible change. Although this sea surface temperatures could reach up to 3°C
21 by 2100. Figure 2‑6 captures this observation of tidal range maximum occurs in July (summer) sea level change, where each study reviewed is and the minimum in February for most stations. represented by a different line in the graph. The In northern and southern mid-latitudes, the shaded area and the vertical red and green error lowest sea level in the annual cycle occurs bars represent the 90% confidence interval. The during spring and is highest in the autumn black and red curves denote the deviation from (Hassanzadeh, 1997; Tabata et al., 1998), but over their 1961-1990 average, the shorter green curve the Arabian Gulf, this feature is different. The the deviation from the average of the black vertical extent of the intertidal zone depends curve for the period 1993 to 2003 (IPCC, 2007). mainly on the tidal range, wave action and Warmer SST will lead to thermal expansion in slope of the shore. On sheltered steeply sloping the Gulf and changes in mean sea level. Sea lev- shores, the height of the intertidal corresponds el data collected from 11 stations in the Arabi- closely to the tidal range, narrow throughout an Gulf already indicate rising levels. Increased much of the UAE. Along unprotected coasts, SST could lead to higher peaks of storm surges, strong wave action causes the intertidal zone to increased cyclone intensity, and a greater risk extend upwards above normal high-tide levels. of coastal disasters; warmer waters also under- The tide waves entering the Straits of Hormuz mine temperature-sensitive coastal ecosystem generate two large rotary waves for the functioning. semidiurnal tide (two highs and two lows each Thermosteric sea level is high in the summer day), and a single large rotary wave for the (June, July, and August) and autumn diurnal tide inside the Gulf. This leads to two (September, October, and November) and distinct tide patterns in the Iranian coast of low during spring (May, April, and March) and Arabian Gulf. One is found at eastern boundary winter (December, January, and February). (the Strait of Hormuz) and the other at the The distribution of the thermosteric sea northern Gulf or western. Seas of up to 5.4m level shows larger variations in sea level in swells in the Eastern Gulf tend to predominate spring than in winter. “Worst case scenario” from NW and SE, and swells of 1.8m and higher adaptation measures will need to target spring occur in the Central Gulf. mean sea levels due to both larger thermosteric Baseline sea level elevation and subsequent tidal variations layered on top of large spring tidal variation around a mean is best determined by means (as will be explored in Section 2.4). the monthly mean sea level (mmsl). In Figure 2.4. Increase in the tidal variation 2‑7, we can see how mmsl changes: the blue line shown in the figure at left represents the around the mean predicted (astronomical) tide. By subtracting the Tidal dynamics in the Arabian Gulf are predicted hourly tide from the observed hourly admittedly unusual. At most tidal stations, the water levels (red line), the researchers obtained the residual change in water level (green line).
Improved estimates of sea level trends rely on improving tidal gauge data collection the in the Arabian Gulf. Mmsl data is publicly available for only three years for the UAE (PSMSL, 2008). As such data is insufficient for a tidal analysis; this report relies on existing analysis of tidal dynamics found in the literature, as synthesized below, to best understand how tidal variation may shift with climate change induced sea level rise.
In Safaniya, a coastal town less than two hundred kilometers to the northwest of Ras Tanura, the tide is mixed, though mainly diurnal. Figure 2‑7. Residual change in water level based Whereas in Ras Tanura, a major oil terminal on on observed and predicted water levels. the west side of the Arabian Gulf, has a large
22 Climate Change Impacts, Vulnerability & Adaptation & Adaptation for & United Arab Emirates Impacts, Vulnerability Coastal Zones in the
Figure 2‑8. Location of Safaniya and Ras Tanura. spring-neap cycle and a particularly large tide 1.8m. Minimum tidal ranges occur in the Strait on Julian day 97. This is due to the fact that the of Homuz (Goudie et al., 2000). tropic-equatorial cycle takes precedence over the spring-neap cycle at places where the tide 2.5. Storms frequency and type is mainly diurnal (Figure 2-8). intensity in relation to rising In the southern Arabian Gulf the tidal range sea levels rarely exceeds 2 meters, and in the Gulf of Oman 2.5 meters. Mean trend of increase in sea level Generally, calm or light seas prevail in the Gulf for the Arabian Gulf is about 2.34±0.07 mm/ more than 40% of the year. Thus there is limited year. The mean spring tidal range is 1.7 and concern regarding changes in storm frequency, 1.9 meters “An evolutionary model for sabkha intensity, movement in the Arabian Gulf. El- development on the north coast of the UAE “; Sabh and Murty (1988) explain that the Arabian http://www.infomarine.gr/uae/Mubarek/index. Gulf is influenced by extra-tropical weather html). d; http://www.jstor.org/sici?sici=0016-73 systems because the Strait of Hormuz lies in 98(200003)166%3A1%3C14%3ACCIRAK%3E2.0. the boundary region between the west-to-east CO%3B2-F;. Other resources suggest that the traveling extra-tropical cyclones and the east- mean range is 1.0m while the spring range is to-west travelling tropical cyclones.
23 a second landfall in the Islamic Republic of Iran. While historical record does not go back very far, these types of storms are very, very unusual for this part of the world. Gonu, and the possibility of a similar storm in the future, raised concern due to the Gulf region’s s sensitive coastal infrastructure of heavy oil drilling activities, tanker traffic, and coastal population density. As a sizeable portion of the world’s petroleum exports go through the Gulf of Oman, any slight blip in supply or exporting could be quite noticeable on the world markets.
Some recent global climate model experiments suggest a future decline in tropical cyclone Figure 2‑9. Tropical Cyclone Gonu churns off the frequency (Royer et al., 1998) while others argue coast of the Middle East and southern Asia (NASA). for an increased likelihood of changes in the tropical storms in the event of global warming In 2007, Cyclone Gonu became the first (Knutson et al., 1999; Henderson-Sellers et documented Category-5 cyclone in the al., 1998; Royer et al., 1998 and Krishnamurti Arabian Sea. Gonu made landfall in Oman et al., 1998; Elsner et al., 2008). Although the with maximum sustained winds near 148 km/ studies carried out so far are inconclusive on hr. In Oman, the cyclone affected more than the likely changes in frequency of cyclones, 20,000 people and was responsible for more it is almost certain that an increase in sea than 50 fatalities. In Figure 2‑9, Cylone Gonu surface temperature will be accompanied by approaches the Gulf of Oman and Strait of a corresponding increase in cyclone intensity. Hormuz (NASA, n.d.). Recent studies suggest a possible increase Gonu moved through the Arabian Gulf making in cyclone intensity of 10-20% for a rise in sea
Figure 2‑10. Area of stronger than normal northwesterly winds (Shamal) and higher wind waves.
24 Climate Change Impacts, Vulnerability & Adaptation & Adaptation for & United Arab Emirates Impacts, Vulnerability Coastal Zones in the
Figure 2‑11. Computer simulated distribution of storm surge heights at four different times. (Sabh & Murty, 1989)
Table 2‑1. Saffir-Simpson Hurricane Scale, (FEMA)
Scale Sustained Storm Storm Surge Damage number Winds (km/h) Surge (m) (ft)
Unanchored mobile homes, vegetation and 1 120-150 1.2-1.5m 3’11”-4’11” signs
2 150-170 All mobile homes, roofs, small crafts, flooding. 1.8-2.4m 5’11”-7’11”
3 170-210 Small buildings, low-lying roads cut off. 2.7-3.7m 8’11”-12’1”
Roofs destroyed, trees down, roads cut off, 4 210-250 4-5.5m 13.’1”-18’ mobile homes destroyed. Beach homes flooded.
Most buildings destroyed. Vegetation 5 More than 250 5.5m+ 18”+ destroyed. Major roads cut off. Homes flooded.
surface temperature of 2 to 4˚C. Shamal. Shamal cyclogenesis, the generation of cyclone-speeds winds and even cyclones from Any increase in sea surface temperature due strong Shamal winds is another factor in storm to climate change would lead to higher peaks surges, however the majority of the UAE is less of storm surges and a greater risk of coastal affected by these winds han other countries disasters. Climatic changes in both moist static in the region. Figure 2‑10 shows a map of the stability of the atmosphere and the underlying SST may be the critical determinants of the strength of Shamal winds. Because the Gulf potential variations of the maximum potential is so shallow, especially in the southwest part, intensity of tropical cyclones in changed climates could be subjected to large amplitude storm (Lal & Aggarwal, 2002). A stronger than normal surges either from tropical or extra-tropical northwesterly winds is known regionally as a cyclones. One advantage of the geology of the
25 26 Climate ChangeImpacts,Vulnerability &Adaptation
Figure 2‑12. Map of Gonu’s path Gulf is that the shallower depth allows for more It was such an unprecedented event there are no friction to dissipate storm surges faster, as the custom ‘storm surge’ models available for that Gulf depth increases with sea level rise this area. The Straits of Hormuz may protect Abu effect may diminish. Dhabi and Dubai (as shown in Figure 2-12), but critical infrastructure on the Eastern coast near Overall, the UAE seems to experience relatively Oman that supports communities in Eastern lower ranges of storm surge, except for positive Emirates (e.g. the Taweelah desalination plant surges of up to 3 meter that can appear in that supplies water to the Al Ain region) would the southwest area at 12 and 18 hours as be at risk. diagrammed in Figure 2‑11 from Sabh and Adaptation for & United Arab Emirates Murty (1989). Surges in these water bodies may have amplitudes of up to 5 to 6 m and there is 2.6. Coastal erosion and shoreline no preponderance of negative surges as in the retreat Arabian Gulf. Surge amplitudes in the Arabian Gulf are comparable to those in the Arabian An indirect, and less-frequently examined Sea and the Gulf of Thailand (Murty, 1984; Sabh influence of sea level rise on the beach sediment and Murty, 1989). If hurricanes of Gonu’s level of budget is due to the infilling of coastal intensity continue, the UAE could see increased embayments. As sea level rises, estuaries and storm surges on the order of those summarized lagoons attempt to maintain equilibrium by in Table 2‑1 on (Vaidya, et al, 2007). raising their bed elevation in tandem, and Impacts, Vulnerability potentially acts as a major sink of sand depositing Coastal Zones in the The implications for the UAE are yet unclear. from the open coast. Recent studies indicate About 6.5% (of about world’s tropical storms that beach protection strategies and changes are formed annually in the Indian Ocean in the behavior or frequency of storms can be (Neumann, 1993; McBride, 1995). The frequency of cyclone formation is 5-6 times more common more important than the projected acceleration the Bay of Bengal as compared to Arabian Sea. of sea level rise in determining future beach Scientists do remark that the frequency and erosion rates (Ahrendt, 2001; Leont’yev, 2003). intensity of summer tropical cyclones forming Thus there is not a simple relationship between in the north Indian Ocean could increase in sea level rise and horizontal movement of the the coming century. Should events like Cyclone shoreline (Cowell et al., 2006). Gonu become more common in the Arabian Sea, In addition to tropical storms, the UAE the UAE's vulnerability will markedly increase. experiences severe thunderstorms. Squalls There will be also increased risks to refueling and result from the subtropical jet-stream re-routing ship-to-ship supply operations in international depressions through the Mediterranean basin, waters, especially near Fujairah, UAE. Winds and and then tracking down the Gulf toward the the atmospheric pressure changes associated Arabian Sea. In most years it rains during the with cyclones also generate storm surges that, winter months, usually in February or March, on top of rising mean sea levels, would severely but occasionally earlier in the form of torrential, damage coastal infrastructure. frontal, and orographic downpours. Winter rains We highlight the extreme risks from storm fall in the Hajar Mountains, and run off rapidly surges because even though for the time into wadis and thence onto the downwashed being it remains an unprecedented event and gravel plains, perhaps reaching the sea on the is even considered by some to be statistically East Coast, but invariably braiding widely and insignificant. A cyclone impairing or destroying soaking rapidly into the desert in the west. production capacity in the world’s most An adaptive response to retreating shorelines important oil region certainly warrants means allowing the shoreline to be flexible. In advanced adaptation planning. Gonu may have contrast, many societies opt to maintain the been an anomaly, or it may be taste of what’s to come. It is up to decision makers to decide the status quo and hold the shore in place with extent to which they want to prepare coastal seawalls and other infrastructure. We will communities for such a low probability, high discuss this more in Section 5 on Adaptation impact event. strategies.
27 3. Climate Change and Coastal Ecosystems
There are multiple ecological subsystems flats that stand only a few centimeters above that have evolved along the coasts of the UAE high-tide mark (See Figure 3‑1 for geographic including: embayment, barrier island-lagoon, visualization of sabkha location along the UAE spit-lagoon, and beach-sabkha subsystems coastline Evans and Kirkham, 2000). There are (Alsharhan and El-Sammak, 2004). The effects three main kinds of sabkhas ecosystems: 1) of climate-induced sea level rise, increases in coastal sabkha, is inundated with marine tides, sea surface temperatures, and other factors 2) supra-littoral sabkha, is rarely inundated by must be studied in the context of each of these tides, and 3) inland sabkha, is never inundated ecosystems. Major ecosystems at risk discussed by tides. Sabkhas form from the interplay in this chapter include sabkhas, mangroves, sea between seasonal inundation of Gulf water, grass, and coral reefs as well as the influence of rain water and sandstorm deposits during the climate change on coastal wildlife populations. hot-dry season. Sabkha ecosystem dynamics are highly influenced by geo-ecological factors 3.1. Sabkhas coastal ecosystems of the surrounding areas: sand, hydrology, vegetation, and climate. Abu Dhabi’s sabkhas coastal ecosystems are a hallmark of the Emirate’s ecological and Abu Dhabi’s sabkha plain is partly depositional geological heritages and cover roughly 60% of and partly erosional. Beach ridges suggest that the Emirate’s coastline (ADEA). Sabkha is the sea level around 4000BC was higher than it is local Gulf Arabic word for a flat, salt-crusted today. As such, the coastal sabkha is made up desert. The sabkhas are low-lying, sand and salt of sediments deposited 4,000 to 7,000 years
Figure 3-1. Coastal Sabkhas in Abu Dhabi. (Evans and Kirkham, 2000)
28 Climate Change Impacts, Vulnerability & Adaptation ago when sea level was a few meters higher. Anticipated sea level rise will lead to coastline When sea levels began to retreat, progradation retreat inland, once again, and low-lying of mainland shore began and continues with sabkha will be flooded by the advancing waters sedimentation and progressive infilling of relatively quickly. For those coastal settlements sheltered lagoons, as well as colonization of and existing infrastructure that are situated newly emerging land as the coastline is shifting in the sabkha zone, they may have a relatively seaward. limited lifespan if and when the pace of sea level rise increases. Even now, sabkhat are vulnerable Sabkhas are the most obviously endangered to exceptional meteorological events like geological feature in the UAE. Coastal sabkhas Adaptation for & United Arab Emirates are regularly flooded from winter rains and strong onshore winds (shamals) that can drive higher spring tides. Natural rainfall-pooling seawater from lagoons inland, over the outer patterns in the Sabkhat are already interfered parts of the sabkhas. with by civil engineering projects along the coastline. Roadway plantations and subsequent 3.2. Mangroves fresh-brackish irrigation applications are The Emirates’ mangroves have a high ecological changing salinities of sabkha water and may value to the Arabian Gulf (Saenger and Blasco, have negative consequences on sabkha flora and 2000; Saenger et al., 2004). Coastal vegetated fauna. Once easy to find near Abu Dhabi Island, wetlands like mangroves are sensitive to climate coastal sabkhas are also quickly disappearing change and long-term sea-level change because Impacts, Vulnerability to make place for roads, power lines, industrial Coastal Zones in the their location is intimately linked to sea level. estates and housing developments. Mangroves play a vital role in the life-cycle of Even though these ecosystems have undergone many valuable seafood species and provide a a lot changes throughout time, particularly safe nesting, feeding and roosting site for many from infilling and fragmentation that occurs birds (Aspinall). Mangroves also offer coastal during development, the evidence of former production by reducing wave energy The Abu coastlines can still be seen. The highway from Dhabi Environment Agency’s 2006 report on Abu Dhabi to the western industrial zone of the Marine and Coastal Sectors, discusses Ruwais, for example, passes across the sabkha, past efforts to inventory existing mangrove and to the south, inland, the old shoreline can habitat. In 2004, the Abu Dhabi’s marine atlas be identified, a low range of hills that mark project, recorded the distribution, density and the beginnings of the desert (Richardson and structure of mangrove vegetation throughout Hellyer, n.d.). The old shoreline then reached the Abu Dhabi Emirate; Figure 3‑2 is a map derived low cliffs that can be seen south of the highway from this survey data. Mangroves naturally to Tarif, the shore may return to that place as occur between Ras Ghanada in the northeast to seas rise, which is fine for sabkhas development Marawah Island further to the west at suitable but less fine for existing road networks and sheltered sites that have reduced wave energy built environment that depends on coastline in and are protected from strong winds. Data from its current position. remote sensing suggests that there are about 40 km2 of mangroves in Abu Dhabi. Most sabkhas, at least coastal sabkhas, are only a few meters above sea level. The lack Sasekumar, et al., (1994) explain that mangroves of topographic relief and altitude allows sea are found above sea level because the mud where water to move several kilometers inland during they take root needs to be totally exposed, high tide, rare storm surges, and even further or free from inundation, for some period each inland with future sea level increases. Without day. Under situations of constant inundation, adequate adaptation, sabkhas human and mangrove root systems are unable to take in faunal populations may have to relocate inland. oxygen and new trees will be unable to take root Additionally, any change precipitation and as seeds float in higher water. Additionally, any sea levels due to climate change will alter the increase in extreme storms may induce erosion evaporites that are at the core of ecosystem of the mudflats, around which mangroves thrive. functioning (Lieth and Menzel, 2002). Mudflats do undergo a natural cycle of accretion
29 Figure 3‑2. Mangroves around Abu Dhabi, (E.A. data layer.) and erosion, but storms could mean damage to as a habitat for the growth of both commercial the system and subsequent irreversible coastal and non-commercial fish and invertebrates, erosion. and especially as a refuge from predators for juvenile fish (ADEA, 2006).
3.3. Seagrass The very high growth rate and primary Seagrass ecosystems have huge ecological production of seagrasses also leads to extremely importance for coastal areas of the Emirates. high biodiversity (both plants and animals) Seagrasses predominate coastal shallow water as well as facilitates major nutrient recycling habitats of water depths less than 10 meters. The pathways for both inshore and offshore majority of the UAE coastline, along the shallow habitats. The perennial habitat maintains local Arabian Sea, meets this criterion. Seagrasses biodiversity and serves as a foundation for provide a stable coastal habitat, improve coastal complex food chains because of its high rate water quality, and support fisheries production of primary productivity and high leaf densities. making them one of the most valuable marine Seagrass detritus also contributes nutrients and resources and ecosystems (Bell and Pollard, energy to sabkha substrate, contributing to the 1989; Bostrom and Mattila, 1999; Heck and development of storm-berms at seaward edges Orth, 1980; Heck et al., 1989, 1995; Orth et al., and supporting halophytic fauna and flora. 1984; Thayer et al., 1979). The importance of Halophytic root systems then help stabilize the the seagrass systems in Abu Dhabi lies not only Sabkha substrate which minimizes the effect of in the direct food value to wildlife such as the wind erosions and retains water in coastal soils dugong and green turtle, but also in its value (Phillips, 2002).
30 Climate Change Impacts, Vulnerability & Adaptation Scientists have every reason to believe that, as tidal range will decrease the amount of intertidal with the predicted terrestrial effects of global exposure at low tide such that plant distribution climate change, impacts to seagrasses will be expands shoreward. In shallow waters, these great. Short and Neckles (1999) highlight a need subtidal species may be able to expand inland for more research directed toward the impact of towards intertidal areas and continue to global climate change on seagrasses. Seagrass thrive (Kentula and McIntire, 1986). Where habitats are influenced by sea temperature geomorphology or human infrastructure does regimes, tidal variations, salinity content, not permit successful ecosystem migration, the changing water depths, as well as ocean carbon UAE can expect a loss in seagrass areas. & Adaptation for & dioxide content. Tidal height and tidal range United Arab Emirates effects on available light, current velocities, 3.4. Coral Reefs depth, and salinity distribution, are all factors that regulate the distribution and abundance of Coral reefs are Abu Dhabi’s most diverse seagrasses. marine ecosystem. The variety of life and the complex interactions of reef organisms are of These climate factors are all implicated in major fisheries, scientific and tourism value to expected regional climate changes. Organisms the Emirate. Sea levels in the Arabian Gulf have in tropical waters are known to live much closer been near present levels for about 2000 years to their upper thermal limits. An assumption (Lambeck, 1996), and have therefore provided that follows is that as the waters of the Gulf reach corals with a stable bathymetric environment Impacts, Vulnerability extreme limits of temperature and salinity, the in which to develop into reefs (ADEA, 2006). Coastal Zones in the same would be true for the three seagrass species Corals are vulnerable to thermal stress and have that live in it. Change sea surface temperatures low adaptive capacity. Increases in sea surface could lead to altered growth rates and even temperature of 1 to 3°C are projected to result impair other physiological functions of the in more frequent coral bleaching events and plants like sexual reproduction or geographic widespread mortality, unless there is thermal distribution. Temperature changes that lead adaptation or acclimatization by corals (IPCC, to increased eutrophication and changes in the 2007). Coral bleaching and mortality appear frequency and intensity of extreme weather related to the frequency and intensity of ENSO events indirectly affect seagrass ecosystems. events in the Indo-Pacific region, which may alter as a component of climate change (IPCC, Numerous studies have shown an association 2007). between seagrass distribution and water depth (Short et al., 1999 cites the following: Since 1995, there has been a heat-induced Zimmerman and Livingston, 1976; Bay, 1984; die-off of around 90 per cent of all coral in Averza and Almodovar, 1986; Dennison and the southern Gulf. In 1996 and 1998, the UAE Alberte, 1986; Dawes and Tomasko, 1988; Orth experienced two catastrophic coral bleaching and Moore, 1988; Duarte, 1991). Sea level rise, as events associated with seawater temperature it contributes to increased water depth, leads anomalies. These prolonged higher-than normal to a subsequent reduction in light available for summer seawater temperatures (positive SST seagrass growth. One study suggests that the temperature anomaly of over 2°C) led to the projected 50 cm increase in water depth due to catastrophic bleaching and death of a large sea level rise over the next century could reduce percentage of the previously living corals along available light by 50%, which in turn may cause the length of Abu Dhabi Emirate. High seawater a 30-40% reduction in seagrass growth and temperatures have often been close to or may productivity (Short and Neckles, 2002). have exceeded the physiological tolerance limits. Changing tidal range is likely to exacerbate the effects of increased water depth on seagrass The long-term prognosis for the survival of habitats; however, whether tidal range remains coral reefs in the Emirates, if summer seawater the same but just shifts with sea level, or if sea temperatures continue to rise, is not good. level rise actually influences high and low tide In the past, poor development of reefs in the levels is yet to be determined. Any decrease in southern Gulf has been attributed to high
31 sedimentation and low winter temperatures Gulf corals because so much of the southern (Shinn, 1976). Now, water temperatures in the shoreline is barely above sea level. While the Gulf exceed 33°C in summer, falling in winter effects of flooding remain unclear, researchers to 16°C in the north and 22–24°C in the south anticipate that coastal flooding could mobilize (Chiffings 1994). Some level of resilience could sediments and induce reef “switch offs” similar be expected because reefs exist in this area of to flooded lagoons and drowned barrier reefs historic environment stressors such as extreme as seen in US Virgin Islands. Reefs would also fluctuations in seawater temperature and be damaged from the extensive area of shallow high salinity (Kinsman, 1964; Sheppard, 1988; sea created by flooding, these “seas” would Sheppard & Sheppard, 1991) as well as frequent be lethally heated and cooled by the Gulf’s high turbidity. On the other hand, scientists temperature extremes (Loughland, 2005; warn that corals have probably reached their Loughland and Sheppard, 2001, 2002; Riegl upper physiological temperature limit of 2001, 2002, 2003). the already well-adapted hermatypic corals forming the reefs of Abu Dhabi (EA). Already, there is evidence of the temperature sensitivity 3.5. Influence of sea level rise and sea of coral because at the western extremity of surface temperature warming the Abu Dhabi coastline the annual range of on coastal fauna. seawater temperatures is somewhat greater and consequently coral diversity is less (George Many of the Emirate’s islands hold internation- & John, 1999, 2004, 2005b; John & George, 2001: ally important numbers of breeding seabirds Riegl, 2003). and numbers of visiting shorebirds, nesting and Riegel (2003) also explains that sea-level rise feeding grounds of turtles, cetaceans (including would have severe impacts on nearshore Arabian both whales and dolphins) and dugong herds,
Figure 3-3.Kingfish abundance vs. SST.
32 Climate Change Impacts, Vulnerability & Adaptation amongst others. Sea level rise may induce pressures. While UAE Federal Law protects changes in turbidity, temperature and salin- them to an extent, sea level rise and changing ity that affect all of these flora and fauna. Any in coastal water temperatures may negatively changes in ecosystem conditions could lead to affect the habitats in which they thrive—notably improved conditions for diseases of plants and the sea grass communities which are sensitive animals, as well as open areas to invasive spe- to both water depth and salinity. cies. The abundance of some of the Emirate’s most The bathymetry of the Gulf is already quite important fisheries like kingfish are associated shallow; sea level rise would extend these with these seasonal climate patterns, e.g. the Adaptation for & United Arab Emirates shallow coastal areas inland. The problem with extreme temperature fluctuation between the shallower water is that it is more susceptible to summer and winter months (see Figure 3-3). strong heating and cooling, and density changes Depending on how ambient and sea surface from evaporation, both of which negatively temperatures change over time, kingfish and affect temperature sensitive species that had other similarly vulnerable populations will either lived along the coast before changes forced need to migrate, adapt to new temperatures in migration. their current habitat, or potentially become Much of the Abu Dhabi Emirate’s unique extinct. These options hold true across the biodiversity is found in coastal ecosystems. The board for both animal populations as well as hawksbill turtles breed on more remote beaches, populations of sea grasses and mangroves who Impacts, Vulnerability Coastal Zones in the and dugongs are found in great numbers feeding may be able to adapt to slow paced change on the seagrasses in more sheltered waters. but ill equipped to handle abrupt sea level Dugongs are already threatened internationally, rise, particularly when coupled with existing mostly from drift nets and other man-made anthropogenic pressures.
33 4. Inundation analysis of coastal areas
After much debate, the general agreement is and development patterns often undermine that “vulnerability is neither an outcome nor a coastal ecosystems’ abilities to respond to static internal condition but rather a dynamic these natural phenomena and, when juxtaposed property emerging from the structure of human against the added extreme changes expected relations, the internal attributes of specific from climate change, vulnerability is an even populations and places, and the nature of social- more pressing concern. Vulnerability to sea environmental interaction” (Encyclopedia of level rise causes particular anxiety for coastal the Earth). The goal of any model in which societies like those along the UAE’s Arabian Gulf vulnerability is operationalized is to then capture shoreline, since the ability of coastal systems to both the internal and external dimensions of adapt to rising seas is inherently constrained vulnerability. The benefit of obtaining a better by the extensive human infrastructure found understanding of vulnerability is that it can on the coast. At the same time, the human better inform policymakers to the appropriate built environment buffering those ecosystems response actions. With respect to climate face its own challenges from sea level rise. In change, the magnitude of vulnerability can then the inundation analysis, both ecosystems and be met with adequate adaptation measures. human systems, and the extent to which they What follows is a quantitative assessment of are vulnerable to four different scenarios of sea the UAE coastline’s vulnerability to sea level level rise are considered. After a discussion of rise. The initial focus was on the urban built the methodology is a description of scenarios environment in each of the major cities of the used and their results. UAE (i.e., Abu Dhabi, Dubai, Sharjah, Umm al- Quwain, Ajman, Ras Al Khaimah, and Fujairah). 4.2. Methodology Where data permits, this was included in the study. For the non-built environment, the focus Geographic Information Systems (GIS) was was on the coastline of the Abu Dhabi Emirate the main tool used in the analysis. GIS is a only. software tool that allows for the representation of data in spatial form, both in two dimensions 4.1. Introduction and three dimensions. The use of this software will facilitate the management and integration Coastal systems are inherently dynamic and of data, the performance of advanced spatial continually changing in response to natural analysis, modeling and automating certain processes like tides, and other global ocean- processes, and displaying results in high-quality atmospheric interactions like the North maps for presentation purposes. Atlantic Oscillation (NAO), El-Nino Southern Oscillation (ENSO) and seasonal rainfall and The sections below reflect on previous attempts sea-surface temperatures. Human decisions to use GIS in conducting a spatial assessment
Figure 4-1. Depictions of two main sea level rise modeling strategies.
34 Climate Change Impacts, Vulnerability & Adaptation & Adaptation for & United Arab Emirates
Figure 4‑2. Data displaying areas susceptible to sea level rise. (University of Arizona)
of zones of inundation from sea level rise, or the areas of the same elevation. As you can see a identification of vulnerable zones under different +1 meter ‘rise’ scenario results in the labeling scenarios. We reflect on how we have defined Mean of inland cells as vulnerable to sea level rise Impacts, Vulnerability Sea Level, in this study, and the implications of when they are are also at 1 meter of elevation Coastal Zones in the our assumption on changes in sea level based on regardless of whether flood waters will actually that mean. We review further the data limitations travel that path. and methodological considerations which posed a challenge to mapping sea level rise in Abu A group of researchers at the University of Dhabi and explain in detail how we used GIS Arizona, worked to determine areas susceptible and a flood-fill algorithm to map contiguous to sea level rise of one to six meters using a zones of vulnerability at 1 meter, 3 meter, and 9 1km DEM (GTOPO) for a global model, and meters of inundation and the data that underlies a 30-meter cartographically derived DEM our analysis. for their model of the US. According to their researchers, the SRTMs were not available There are two main ways that researchers at the time of their inundation map creation spatially model sea level rise and subsequent and they seemed to indicate they would have coastal inundation (see Figure 4-1). The two chosen it over the 30-meter DEM (J. Weiss, GIS methods are A, a contour-based method personal communication, February 26, 2008). that relies solely on elevation data, while some Their method differs from Titus and Richman low-lying areas appear inundated despite being (2001) and Mulligan (2008) in that they created surrounded by areas of higher elevation, as an algorithm to conduct cell-by-cell analysis of was done by Mulligan (2008) (see Figure 4‑3) their chosen DEMs. They determined for each and B, using a more accurate flood-fill model cell whether its elevation value was less than or that identifies low elevation ‘sinks’ that only equal to a particular integer and, if so, whether flood when the ‘pour point’ is reached. (Note: or not this cell is adjacent or connected to the the ‘pour point’ for coastal flooding is the value of elevation that water needs to reach before sea by cells of equal or lesser value (UofA, 2003). flowing into the ‘sink’) as was done in Figure The University of Arizona results are shown in 4‑1 (Brown, 2005). An error with either method, Figure 4-2. recognized by two reports is that elevations do Similarly, researchers at the Center for Remote not directly state how far the land is above sea Sensing of Ice Sheets (CReSIS) at the level. University of Kansas simulated global sea level 2 Titus and Richman (2001), Mulligan (2008), rise for 1- 6 meters, using Global Land One-km and Stanton and Ackerman (2007) all rely on Base Elevation (GLOBE) digital elevation model the first method. The drawback is the lack (DEM). The GLOBE DEM covers the entire of differentiation between coastal and inland world with a spatial resolution of 30 arc seconds
35 36 Climate ChangeImpacts,Vulnerability &Adaptation
Figure 4-3. 1 meter scenario for Abu Dhabi, visualized in Google Earth. (Mulligan, 2008) & Adaptation for & United Arab Emirates Impacts, Vulnerability Coastal Zones in the
Figure 4-4. CReSIS, 6m inundation. (CReSIS, University of Kansas) of latitude and longitude (approximately one adjacent to the ocean are inundated (CReSIS, kilometer at the Equator), with each land cell 2008). in the grid assigned an elevation value (meters) in whole number increments (see output in 4.3. Data limitations, Figure 4-4). methodological Using raster analysis, the University of Kansas considerations: challenges to team identified potentially inundated areas mapping sea level rise based on elevation and proximity to the current shoreline. Using an algorithm, similar to the Accurately mapping areas potentially inundated by rising seas depends on accurate UofA team, they flagged all raster cells adjacent measurements of current mean sea level as to the contiguous ocean and then did a second well as high-resolution terrain data to position order of analysis to flag cells whose elevation in relation to mean sea level. The uneven value is less than or equal to the desired sea distribution of masses across the planet level rise increment. Since the initial pass makes it tricky to measure relative sea level. floods only those cells that are directly adjacent A quick technical tangent explains this fact to the current ocean, the two-step procedure further. The geoid is the level of surface that is repeated until all cells connected with cells the sea surface would assume in the absence of
37 Model of the Earth Modeling anticipated sea-level rise of 1-meter or less is often poorly matched to available contour
Surface of line intervals found in topographic maps (Titus the earth and Richman, 2001). Their project used coarse Land DEMs (1:250,000 series) to illustrate land that is below the 1.5- and 3.5-meter contour lines. The reasons for choosing these contour lines lie in Sea the fact that were high tide to have an elevation Geoid of 1 meter, then in areas with minimal wave
Ellipsoid erosion, the 1.5- meter lines would be areas potentially inundated were sea level to rise 0.5 meters.
In more complex and rapidly changing coastal The geoid approximates mean sea level. The shape of environments, like wetlands, the 1.5-meter the ellipsoid was calculated based on the hypothetical contour line may be ineffective at conveying equipotential gravitational surface. A significant difference actual inundation levels that are less than 1 exists between this mathematical model and the real object. meter (Titus and Richman, 2001). Even if flat, However, even the most mathematically sophisticated geoid can only approximate the real shape of the earth. coastal areas are more likely to have reliable DEMs (Wu and Najjar, 2006); Titus and Richman Figure 4‑5. Model of the Earth, approximating sea (2001) reviewed available topographic maps level and geoid. (Fraczek, 2003) for various countries and found the vertical resolution ranged from 1 meter to 40-50 meters. If 5-10 feet is the smallest increment we have for external gravitational forcing. modeling sea level, researchers interested in 18- Sea level approximates the geoid in most areas, 60 centimeter sea level rise by 2100 (IPCC, 2007) and as the geoid migrates depending on various are going to be limited in their ability to model geo-physiological changes in the earth’s core, near-term impacts of climate change. the level of the sea must migrate similarly In contrast to ill-suited contour lines, the (Figure 4‑5 from Fraczek, 2003). Most maps National Aeronautics and Space Administration and mapping systems, however, use a reference (NASA) Shuttle Radar Topography Mission ellipsoid- which is an idealized, smoother (SRTM) developed global and US national rendition of the earth’s surface that may suggest elevation data. The SRTM data were collected misleading mean sea levels on which sea level with a technique known as interferometry that rise scenarios are layered (Fraczek, 2003). allows image data from dual radar antennas Coastal risk assessment to sea level rise has to be processed to extract ground heights become a major area of research over the (USGS, 2006). NASA released data at 90-meter past couple decades, however, assessments resolution globally and 30-meter resolution for the USA. To date, the SRTM dataset at are still limited by the availability of accurate 90m resolution is the best publicly available data. NOAA (2006), USGS Woods Hole Field topographic datasets for near-global use. For Center (Thieler et al., 2007), the Clean Ocean higher resolution and more localized data, and Shore Trust (2001), in addition to many on international projects researchers must university departments (UofA, 2003; Yohe et rely on national or municipal DEMS that are al., 2006; CReSIS, 2008) have taken on the likely cartographically or photogrammetrically task of mapping those areas at greatest risk derived (Mulligan, 2007). to inundation. Titus and Richman (2001), for example, mapped lands vulnerable to sea level Mark Mulligan, a researcher at the University rise along US coastlines. Challenges experienced College of London developed sea level rise in accurately representing coastline elevation scenarios in collaboration with NASA using are different from inland elevations due to their SRTM dataset. With the SRTM data, land subsidence, tides, and other factors that Mulligan (2008) and his team were able to map complicate models. the following scenarios according to the CSI
38 Climate Change Impacts, Vulnerability & Adaptation processed SRTM topographic dataset available: 1) -120m, the sea levels during the last glacial maximum (approx, 18,000 years ago); 2) +0m, calculated for error assessment; 3) +1 meters ; and 4) +4 meters of sea level rise. He explains, “given that the typical error in SRTM altitudes is of the order of 3 meters in most coastal areas […] this is a very preliminary analysis intended as a global first assessment and can be much & Adaptation for & improved by taking on board (a) tides and tidal United Arab Emirates ranges, (b) better error assessment, (c) improved DEMs in critical areas such as coastal cities” (Mulligan, 2008).
While the SRTM dataset is helpful in Figure 4‑6. Illustration of how the LIDAR understanding 1 meter sea level rise from the sensing instrument captures elevation points. mean (0 in our dataset), it poses challenges when interested in modeling 0.3 or 0.6 meters recommendations for investing in select area sea level rise—which is what the IPCC posits for of LiDAR data. Some countries and cities 2050 and 2100 respectively (excluding ice-sheet have made the investment in LIDAR (Light Detection and Ranging) data. Impacts, Vulnerability dynamics). Coastal Zones in the
The challenge, to date, has been estimating Mosaic Mapping Systems Inc., (2001) described vulnerable zones based on these <1 meter the accuracy of LIDAR data as a function of SLR scenarios while using topographic maps terrain type and vegetative cover; in areas and digital elevation models whose vertical of extremely dense vegetation, like tropical resolutions range from 1.5 to 10 to 100 meter rain forests, the percentage of laser points intervals. To come with broad estimations of that penetrate the canopy and reach the places that may be at risk, studies have strived ground decreases influencing the accuracy of to use the best available data and interpolation resultant DEMs. The relative accuracy of data methods, with the likely exception of the highly is summarized in the table below: accurate (and highly expensive) -- LiDAR data LIDAR data has been used widely develop DEMS have errors in the range of +/- 0.3 meters-- the and field data for the delineation of floodplain accuracy of these estimations will remain a boundaries and identify areas at risk to flood problem. LIDAR is three technologies integrated hazards. Using LIDAR to collect shoreline into a single system- lasers, global positioning topography has proven to be faster and less costly system (GPS), and inertial navigation systems than traditional beach surveying methods in some (INS) (Mosaic, 2001). Figure 4‑6 explains how areas. LIDAR enables the collection of shoreline the LIDAR’s integrated technologies work measurements used to determine erosion rates, together to create high resolution datasets. or sand volume needs for beach nourishment Broad estimations using lower resolution projects, for example, as well as measuring the datasets, however, point roughly to areas effectiveness of existing management strategies for more precise studies and can be used in like jetties and seawalls (NOAA, 2007). Coastlines
Table 4‑1. Relative accuracy of LiDAR data. (Mosaic Mapping Systems, 2001)
+/- .15 meters (vertical accuracy) Hard surfaces and open regular terrain
+/- .25 meters (vertical accuracy) Soft/vegetated surfaces (flat-rolling terrain)
+/- .30-.50 meters (vertical accuracy) Soft/vegetated surfaces (hilly terrain)
All but extremely hilly terrain (depending on flying +/- .50-.75 meters (horizontal accuracy) height and beam divergence)
39 Figure 4‑7.Comparison of 30-meter USGS, 10-meter USGS, and 3-meter LiDAR data for US coast. (Wu and Najjar, 2006) are highly dynamic environments- need frequent they concluded that using the DEM30 was an update of baseline data such as periodic LIDAR “appropriate” choice for making future sea-level missions and SRTM data as it is available, rather rise inundation estimates (acknowledging that than relying on DEMs derived from outdated the maps produced are a first-order assessment, cartographic maps. and more detailed-assessments are needed).
Wu and Najjar (2006), as part of the Consortium 4.4. Defining mean sea level for the for Atlantic Regional Assessment (CARA) project, compared DEM data from quad maps UAE: reliance on tidal and elevation (both 10-meter and 30-meter for the US) data with available LIDAR data (interpolated to a As previously mentioned, baseline sea level 5-meter grid) (See Figure 4-7). Their goal was to elevation and subsequent tidal variation around determine the level of accuracy of the DEMs in a mean is best determined by the monthly five coastal areas and the associated error in the mean sea level (mmsl). Most researchers rely inundation estimates. They compared .38-, .66-, on tidal data to estimate the elevation of spring and 1-meter sea level rise scenarios using DEM high water, which is the highest level the sea and LIDAR layers and then pooled the results reaches during the year and is thus a salient to estimate the area inundated, summarized in benchmark when determining worst-case Table 4‑2. scenario sea level rise. The spring high tide is From their analysis, and based on the relatively generally the Mean higher high water (MHHW). small average discrepancies between DEMs In spatial analysis, we used the MHHW as a and LIDAR in calculating inundated areas, tidal datum, or the average of the higher high
Table 4‑2. Comparison of inundated areas using different elevation datasets. (Wu and Najjar, 2006)
Inundated area (km2) Difference with LIDAR(%) LIDAR Sea-level Rise DEM30 DEM10 DEM30 DEM10 mean Below 0.38 m 8.72 8.70 8.09 7.80 7.47 Below 0.66 m 8.87 8.88 8.54 3.95 4.04 Below 1 m 10.29 10.32 9.47 8.66 9.03
40 Climate Change Impacts, Vulnerability & Adaptation water height of each tidal day observed over the SRTM data is also only available in integers National Tidal Datum Epoch. Unfortunately, the implications of which, with respect to the Mmsl data is publicly available for only three floodfill model, limits the scenarios we can run years for the UAE, (PSMSL, 2008) and MHHW to the values in the existing data set. was not available from sources consulted. Since The flood fill program considers the elevation available tide data is considered insufficient for values in the cells of a grid, and then assesses a tidal analysis, this report relies on existing the elevation differential from the elevation in analysis of tidal dynamics found in the literature, neighboring cells. Take the example grid cell as referenced below, to best understand how
shown in Figure 4‑8. Those cells with a value of Adaptation for & tidal variation may shift with climate change United Arab Emirates “0” signify mean sea level. When one adds a 1 induced sea level rise. meter scenario to the grid in Figure 4-8b, the Mean sea level is not just influenced by flood fill program calculates which neighboring tidal dynamics but by Arabian Gulf thermal cells in 8 directions (N, S, E, W, NW, NE, SW, expansion as well. For a detailed explanation SE) the water could possibly travel, based on of those dynamics it is suggested to revisit elevation. With 1 meter rise, inundation will sections “2.3 Sea-surface temperatures, thermal extend to the blue-shadec cell. In the case expansion, and thermosteric sea level rise” and where sea level rises by 2 meters in Figure 4-8c, “2.4 Increase in the tidal variation around the inundation extends throughout the shaded 1 mean”. Separate from these processes, which meter and 2 meter cells, and are only blocked by Impacts, Vulnerability have altered sea levels for millennia, based the 3- and 4-meter cells inland. Our reliance on Coastal Zones in the on the available literature, net sea level rise is the SRTM dataset, also determines where mean defined as the historical sea level rise rate plus sea level is in our model. The SRTM vertical the accelerated rate due to global warming datum is mean sea level and is based on the minus the estimated accretion rate for each WGS84 Earth Gravitational Model (EGM 96) type of tidal wetland calculated annually over geoid. The EGM 96 is the closest approximation the 200 year time period (Jones and Strange, of the geoid in most areas, and therefore mean 2008). sea level (since sea level mirrors the geoid as explained by Figure 4‑5). For lack of better elevation data, the analysis on SRTM data is from the CGIAR-CSI 4.5. GIS and a flood-fill algorithm (Consortium for Spatial Information) GeoPortal which provides processed SRTM 90m DEM for As explained in Section 4.2, there are two main the entire world. Produced by NASA originally, sea level rise (SLR) modeling approaches the data made available by CGIAR-CSI was typically drawn upon. Either one is suitable processed to fill data voids and to facilitate its for GIS analysis. Inaccuracies arise, however, ease of use by a wide group of potential users. when deriving a vulnerable zone based on the This was found to be the most comprehensive contour-method because it does not consider and consistent elevation data for the United contiguous cells the way that a pour-point or Arab Emirates available publicly at the time flood-fill model would. SEI developed a flood- of the analysis. Also, it is worth noting that the fill program to calculate flooded areas adjacent
Figure 4-8a (0m) Figure 4-8b. (1m) Figure 4-8c (2m)
1 1 2 2 2 1 1 2 2 2 1 1 2 2 2
0 2 2 1 3 0 2 2 1 3 0 2 2 1 3
4 1 2 2 3 4 1 2 2 3 4 1 2 3 3 4 1 1 2 0 4 1 1 2 0 4 1 1 2 0 4 1 2 2 0 4 1 2 2 0 4 1 2 2 0
Figure 4‑8 a,b,c. Example flood-fill process.
41 to water using SRTM data. i) 2050: 1 meters above mean sea level
In this way, the floodfill algorithm was used ii) 2100: 2 meters above mean sea level to establish ‘vulnerable zones’ of inundation Scenario #2: Accelerated ice cap melting at specified scenarios of sea level rise. For detailed GIS methodological steps of how these iii) 2050: 3 meters above mean sea level vulnerable zones were overlain with urban iv) 2100: 9 meters above mean sea level infrastructure and coastal ecosystem data to quantify areas and locations vulnerable to sea For each scenario (where data allows), we have level rise, see Annex 1. quantified the area inundated for Abu Dhabi based on the Environment Agency’s land use and 4.6. Scenario development ecosystem classifications: mangrove, sabhka, salt marsh, sea grass, built up area, empty areas, In developing our scenarios, we modeled those road buffer, agriculture, forests, urban greening areas outside the intertidal zone to identify or amenity, archaeology sites/areas of significant areas newly inundated given certain degrees historical/cultural value, and populations of sea level rise. As discussed previously in the based on a rough estimate of city location and southern Arabian Gulf the tidal range rarely population. The focus of the analysis is on the exceeds 2 meters, and the mean spring tidal Abu Dhabi Emirate, however, the elevation data range is 1.7 and 1.9 meters. Other resources inherently covers all UAE coastal cities, including suggest that the mean range is 1.0m while the those summarized in Table 4 ‑3. spring range is 1.8m. The tidal range is the vertical difference between the highest high 4.7. Results and Discussion tide and the lowest low tide; most extreme tidal range (otherwise known as the spring Cartwright et al. (2008) note that extreme tide) occurs when the gravity of both the Sun high tides tend to be experienced at certain and Moon are pulling the same way or exact times of the year, most notably during the opposite way (full). For simplicity and because spring and autumn full-moon spring tides. As the SRTM data is only available in integers, we such the probability of sea-level rise events use 2 meters as the tidal range. causing the type of damage described in this report is unevenly distributed throughout the SLRn = Mean Sea Level (0) + (tidal range)/2 + year and tends to be clustered around certain, n meters SLR reasonably predictable, times of the year In practice this means that we ultimately shift (spring tides). The analysis assumes that the our elevation-based scenarios +1 meter to government is interested in planning for at least establish sea level rise outside of the existing the shorter estimate of 2050. This is a somewhat tidal range: extended period over which fixed infrastructure depreciates, however, given that the probability SLRn = Mean Sea Level (0) + 1 + n meters of these extreme high tide events may increase as SLR the frequency and intensity of storms increases, We have chosen to model four scenarios of sea and that mean sea-level rise impairs the ability level rise, representing different plausible rises of coastal systems like the sabkhas to act as over the next century or so. The likelihood of natural buffers to such events it may be worth it these scenarios is largely dependent on degrees to prepare coastal infrastructure for 1-3m higher of warming (2˚C to 4˚C) and the extent to which sea levels in the short term. global warming continues to influence ice cap The impacts of sea-level rise cannot be fully melt. We do know, however, from research by understood without some discussion of human Jim Hansen of NASA’s Goddard Institute, that activities in the coastal zone. There is a growing there is plausible scientific basis to show that awareness of the potential for (often well- linear projections of sea-level rise are no longer meaning) efforts aimed at responding to natural acceptable—making room for abrupt changes, disasters to inflict unforeseen consequences in the case of arctic melt, for example. and damage of their own that outweigh the Scenario #1: No accelerated ice cap melting benefits of the action (Parry and Carter, 1998).
42 Climate Change Impacts, Vulnerability & Adaptation Table 4‑3. UAE Coastal Cities.
Arabian Gulf Cities Sharjah Al Batinah Coast Cities Al Mafra Ajman Hisn Diba Tarif Umm Al Qaywayn Khawr Fakkan Abu Dhabi Jazirat Al Hamra Al Fujayrah
Dubai Kalba
It is, for example, now accepted that in the wake To provide readers with a sense of the extent of & Adaptation for & of the tsunami that devastated the Indonesian inundation, the following pages include several United Arab Emirates coastline, ill-conceived and mis-directed relief summary maps that depict the vulnerable zones efforts contributed to the undermining of local in each scenario; however, more detailed maps livelihoods. are included in Annex 2: Inundation maps.
One of the findings of this study is that the Using the Abu Dhabi Coastal Ecosystems as risks of sea-level rise are caused not only by the our base map, we have overlain the three sea biophysical impact of high seas, but also by the level rise scenarios listed below on top of the social and institutional changes that these high- various coastal ecosystems for inclusion in the sea events trigger. Abu Dhabi has ambitious main body of this report. Additional inundation coastal development plans as outlined in maps are provided in Annex 4. Impacts, Vulnerability Coastal Zones in the its 2008 Year in Review. One infrastructural Scenario #1: No accelerated ice cap melting improvement is the underground rail, slated i) 2050: 1 meter above mean sea level for 2010, which will need to account for coastal Scenario #2: Accelerated ice cap melting intrusion of seawater. Also, Saadiyat Island to ii) 2050: 3 meters above mean sea level the east of the Corniche is being transformed iii) 2100: 9 meters above mean sea level into a luxury leisure and cultural destination.
Yas Island is already the emirate’s sports 4.7.1. 2050: 1 meter above mean sea and leisure centre, and will be home to a new level Ferrari Theme Park, a Formula One circuit, a water park and several golf courses, polo fields, At a bird’s eye view, it is difficult to tell what equestrian centre and high-end hotels. With exactly is inundated as the sea rises one meter. respect to Dubai, the number of traffic lanes Much of Abu Dhabi remains above water, but crossing Dubai Creek is being increased from 19 is that because it actually is higher than 1m in 2006 to 47 by 2008, and to 100 by 2020—while above the sea or due to the fact that the way these roads may be okay through 2020 and the data was collected- elevation values were beyond, infrastructural improvements beyond taken off of infrastructure heights, rather than using ground truths. that may need to take into account higher mean sea levels (UAE National Media Council, Zooming into Abu Dhabi city center, it is easier 2008). If sea level rises to street or foundational to see where the lower-lying areas of the coast levels of urban structures then there are several are and where once certain areas flooded, water potential impacts. First, the structure itself continues to flood inland areas. could compact on top of the soil. There may also be general subsidence of the soil (El Raey 4.7.2. 2050: 3 meters above mean et al., 1999). sea level (Accelerated ice cap Cost implications of a changing coastline with melting) respect to the tourist industry and other sectors Several more offshore islands are visibly dependent on coastal infrastructure could be underwater now; and inland flooding is the subject of additional study. To evaluate extensive. Comparing this with key features effective anticipatory adaptation, this financial highlighted in Google Maps (below), the 3m component is critical, however, outside the map suggests that Mangrove Village is flooded, scope of the current study.
43 44 Climate ChangeImpacts,Vulnerability &Adaptation
Figure 4‑9: Abu Dhabi Coastal Ecosystems, no Sea level rise. 45
Figure 4-10: 1 meters above mean sea level by 2050
Impacts, Vulnerability & Adaptation for Coastal Zones in the United Arab Emirates 46 Climate ChangeImpacts,Vulnerability &Adaptation
Figure 4-11: 3 meters above mean sea level (Accelerated ice cap melting / by 2050) (Regional View) 47 Figure 4-12: 3 meters above mean sea level (Accelerated ice cap melting / by 2050) (Zoom view on Abu Dhabi)
Impacts, Vulnerability & Adaptation for Coastal Zones in the United Arab Emirates 48 Climate ChangeImpacts,Vulnerability &Adaptation
Figure 4-13: 9 meters above mean sea level (Accelerated ice cap melting) by 2100 (Regional View) as well as parts of the Industrial City south on how it chooses to adapt over time, but also of the main island. We know that much of the on numerous other factors like continuing to mangroves northeast of the main island are of emit greenhouse gas with no global limits, which ecological importance to the region, experts will would force us into a warmer world where need to identify appropriate habitat migration deglaciation was a) possible and b) yielded 9 corridors so that mangroves are able to move meters sea level rise. Additionally, should storm inland as the shoreline retreats. The inundation surges become a reality and no longer a black of seagrass, was we’ve discussed is problematic swan- then these sea level rise/flood fill analyses because of its temperature and light sensitivities. could hint at what the coast would face from a & Adaptation for &
More research should be done on its ability to United Arab Emirates pending storm surge of that magnitude. Please migrate inland to shallower waters. note, that modeling storm surges and their probability were outside the scope of the report 4.7.3. 2100: 9 meters above mean sea and we merely hint at the possibility to suggest level (Accelerated ice cap melting) more research is needed.
At 9 meters of sea level rise, Abu Dhabi will look 4.8. Summary Tables fundamentally different as a city and society from what we know it as today. A great deal of The tables below provide a summary of the what will define that future community depends spatial extent of inundation for the Abu Dhabi and Dubai emirates. Impacts, Vulnerability Coastal Zones in the Table 4‑4. ABU DHABI Zones of Inundation (km2).
LAND USE 1m rise 3m rise 9m rise Mangrove 723 110 116 Sabhka 127 369 908 Built up area 6 24 62 Empty area 3 7 14 Road buffer 4 11 29 farm(s), small 2 7 33 forest 19 55 127 urban greening 109 220 377 urban park 0.4 2 6 TOTAL 344 804 1,672
Table 4‑5. DUBAI Zones of Inundation (km2).
LAND USE 1m rise 3m rise 9m rise Barren lands 2 3 4 Built up Urban 7 133 200 Others (education, hospital, cemetery, etc.) 1 3 5 Transportation (Roads, Ports, Airport) 1 3 4 Grass .4 1 1 Plantation/ Orchard 1 1 2 Woody Vegetation (Prosopis) 0.3 1 2 Shrub (Leptadenia) 0.3 1 1 Coastal/ Saline 0.04 0.1 0.2 Mangrove 0.02 0.03 0.03 WaterBodies 0.2 0.3 0.3 Wetlands (Tidal Flat, Mud Flat, Creek) 1 1 1 TOTAL 14 147 221
49 5. Framework for climate change adaptation in coastal areas
Urban vulnerability to sea level rise includes sedimentation patterns has led to growing both risks to infrastructure as well as on island recognition of the benefits of “soft” protection settlements and coastal cities. In particular, (e.g. beach nourishment, wetland restoration numerous culturally valuable buildings and and creation) and of the adaptation strategies ecological zones are at risk when seas rise and retreat and accommodate, which are discussed shorelines retreat. For example, Sir Bani Yas later in this section. An increasing number of Island is home to a seventh century Nestorian private companies in the industrialized world monastery and church, the only known Christian are now discovering market opportunities for remnant in the country prior to the arrival of implementing soft-protection options. Interest Islam and the largest one ever found in Eastern in the retreat and accommodate strategies is Arabia. And Dalma Island is known for yielding also growing among coastal managers, but these some of the region’s earliest evidence of date strategies require a more integrated approach palm cultivation along with shards of Ubaid or to coastal management than is currently Mesopotamian pottery and finely flaked stone present in many countries, so their application tools. Much of the discussion below focuses on is still less developed. the role of technologies in adapting to the risks In spite of this pattern to consider technologies of inundation and is based on a recent paper by for adaptation other than hard protection, many Klein, et al (2006). structures are still being built without a full evaluation of the alternatives. One reason could 5.1. Historical context for be that hard structures are more tangible and adaptation in coastal zones hence appeal more strongly to the imagination of decision makers and stakeholders and, by Around the world, the historical emphasis for their visibility, may be perceived to provide dealing with coastal hazards has traditionally more safety and hold the sea at bay forever. been on protecting developed areas using In addition, it is generally felt that hard hard structures like sea walls. The actual skills structures are less maintenance-intensive than and technologies required to plan, design and soft structures. However, past experiences build these structures have depended on their suggest that the design of soft structures is required scale and level of sophistication. On particularly important in determining the level a small scale, local communities have used of maintenance required, but that appropriate readily available materials to build protective design and implementation often require structures. For larger-scale, more sophisticated good knowledge of coastal dynamics as well as structures, technical advice and engineering has been required for design purposes, as well effective coastal management institutions. as a contracting firm to build the structure. A second trend for coping with coastal hazards is Until recently, it was rarely questioned whether an increasing reliance on technologies to develop a country’s coastline could be protected and manage information. This trend stems from effectively if optimal management conditions the recognition that designing an appropriate prevail. It has become increasingly clear, technology to protect, retreat or accommodate however, that even with massive amounts requires a considerable amount of data on a of external funding, coastlines may not be range of coastal parameters, as well as a good effectively protected by hard structures. In understanding of the uncertainties involved in addition, increasing awareness of unwanted the impacts to be addressed. National, regional effects of hard structures on erosion and and global monitoring networks are being set
50 Climate Change Impacts, Vulnerability & Adaptation up to help to assess technology needs and information development are prerequisites for opportunities. coastal adaptation in Abu Dhabi, in particular to identify adaptation needs and priorities relative Third, many efforts have been initiated to to the findings described earlier. The more enhance awareness of the need for appropriate relevant, accurate and up to date the data and coastal technologies, often as maladaptive information available to the coastal manager, practices have become apparent. For example, the more targeted and effective adaptation before a new hospital was built in Kiribati in strategies can be. Coastal adaptation requires 1992, a substantial site-selection document data and information on coastal characteristics had been prepared, examining numerous Adaptation for & and dynamics, patterns of human behavior, United Arab Emirates aspects of three alternative sites, but without as well as an understanding of the potential consideration of coastal processes. A serious consequences of climate change. It is also shoreline erosion problem, advancing rapidly essential that there is a general awareness to within eight metres of the hospital, was among the public, coastal managers and discovered by 1995 (Forbes and Hosoi 1995). decision makers of these consequences and of Options to enhance awareness include the possible need to take appropriate action. national and international workshops and conferences, training programmes, online A large-scale global and regional data courses and technical assistance and capacity- repositories could be established for a building as part of bilateral or multilateral number of climatic and socio-economic Impacts, Vulnerability projects. A suggestion moving forward is to variables relevant to coastal zones in the Abu Coastal Zones in the designate sabkha research reserves to better Dhabi Emirate. These sources of data could understand how higher seas will impact an be integrated into a type of Abu Dhabi Sea ecosystem increasingly bordered by man-made Level Center. This Center could also provide infrastructure. As seas rise and more salt is a network for the assessment of climate and deposited inland, recent research suggests socio-economic scenarios as understanding that seawater irrigation could remove the salt evolves at the international level (i.e., IPCC crust and reduce the substrate salinity to ocean assessments) as well as in the Emirate itself. levels thus allowing for reforestation with local The Center should also be a good repository for mangrove species and other halophytes (Lieth detailed information on a range of technologies and Menzel 2002). that can serve to increase the understanding of the coastal system (which involves data The remainder of this section presents a collection and analysis), to conduct planning framework to consider adaptation in the coastal as well as further climate impact assessments areas in the UAE. Specifically, the focus is on a in coastal zones (so that potential impacts can 4-fold framework described in Klein et al (2006) be quantified for given scenarios) and to raise that involves a) the development of information public awareness that some form of adaptation systems, b) development of planning and is necessary. design strategies, c) implementation of such strategies, and d) monitoring and evaluation Many technologies could be “soft” options that of their performance. Note that no attempt are vital to building capacity to cope with climatic has been made to provide all-inclusive lists hazards. For example, some technologies of options and measures for various types of make use of GIS which combines computer coastal environments in the UAE (e.g. coral mapping and visualization techniques with atolls, coasts of inland waters, small islands). spatial databases and statistical, modelling and The measures discussed in the subsections analytical tools. Collected data can be stored below are meant to be illustrative and to in a geographical information system that encourage coastal planners to consider as wide can be useful in developing new insights and a spectrum of options for adaptation as possible information, and visualized for interpretation in the Emirates. and educational purposes.
5.2. Information Systems 5.3. Planning and Design
Regarding information, data collection and When the available data and information point
51 towards a potential problem that would justify refinable testing of specific technologies for taking action, the next stage is to decide which adaptation before these are implemented in action could best be taken and where and the real world. After implementation, newly when this could best be done. The answers acquired data can be analysed to evaluate to these questions depend on the prevailing technology performance. Once created, a criteria that guide local, national or regional GIS database will have further utility in other policy preparation, as well as on existing aspects of management and policy. development and management plans that The modelling of potential futures based on form the broader context for any adaptation plausible scenarios is pertinent for the planning initiative. Important policy criteria that could and design of Abu Dhabi development that influence adaptation decisions include cost- accounts for adaptation, when relevant impacts effectiveness, environmental sustainability, are quantified, alternative adaptation options cultural compatibility and social acceptability are evaluated and one course of action is in Abu Dhabi. In addition, individual emirates selected. Climate impact assessment requires should choose to take a precautionary approach models of relevant changes in morphological, as postponing action involves substantial ecological and human factors, as well as their risks, even though uncertainty may still be interaction over appropriate time scales (i.e. considerable. a decade or longer). The necessary modelling Coastal planners in Abu Dhabi will always face a capabilities are increasing rapidly and current certain degree of uncertainty, not only because developments in information technology are the future is by definition uncertain, but also facilitating the transfer and application of because knowledge of natural and socio- these tools as they are developed. However, the economic processes is and always will remain limitations inherent in all models (i.e. they are incomplete. This uncertainty requires planners representations of a part of reality for a specific to assess the environmental and societal risks purpose) must not be overlooked. Human of climate change with and without adaptation. expertise and interpretation remain essential The information thus obtained can help to for the intelligent use of any model. determine the optimal adaptation strategy and The quality and effectiveness of future planning timing of implementation. There are a number and design process in Abu Dhabi to account for of decision tools available to assist in this sea level rise will be influenced by the context process. Examples of these tools include cost- in which decisions are made. The successful benefit analysis, cost-effectiveness analysis, implementation of many coastal policies, risk-effectiveness analysis and multicriteria analysis. The last technique is particularly including adaptation to climate change, will relevant when great significance is attached likely be increasingly dependent on public to values that cannot be easily expressed in acceptance at the community level, especially monetary terms. if large scale retreat from ocean proximity is involved. In addition to informing the public GIS can assist planners in identifying so as to raise their awareness of the issues at appropriate technologies for adaptation, as well stake, it may also be important to involve them as the optimal locations for their application, throughout the planning process. Gaining depending on the criteria of the decision public acceptance is an important prerequisite maker. One simple, first-order application of for identifying and transferring appropriate GIS in coastal adaptation would be overlaying technologies for adaptation. Further, local scenarios of sea-level rise with elevation and expertise will be required for successful coastal development data to define impact technology implementation, application, zones, as has been demonstrated in this study maintenance and enforcement. through the analysis of sea level rise scenarios. More sophisticated applications may include In response to difficulties encountered in the modelling of morphodynamic and ecological planning and designing adaptation strategies, responses to climate change. In addition, GIS a number of frameworks have been developed allows for the non-invasive, reversible and to assist in these activities. One recent decision
52 Climate Change Impacts, Vulnerability & Adaptation framework that has relevance to the planning measures need to be integrated into broader and design of adaptation is the Adaptation sector specific policies, economic development, Policy Framework of the United Nations or other policy domains. The APF strives to Development Programme (APF) (Lim and enable the integration of national policy-making Spanger-Siegfried 2005). The APF is intended with a “bottom-up” movement that builds on to complement existing policymaking relating participatory processes and local knowledge. to climate change in developing countries, It is structured around the following four major including processes of assessment, project principles: a) adaptation to short-term climate development and monitoring. variability and extreme events is explicitly Adaptation for & United Arab Emirates included as a step towards reducing vulnerability 5.4. Planning for Adaptation: the to longer-term climate change, b) adaptation UNDP Adaptation Policy policy and measures should be assessed within Framework (APF) in coastal a developmental context, c) adaptation occurs zones at different levels in society, including the local level, and d) both the strategy and process by Klein and Nicholls (1998) concluded that which adaptation activities are implemented most coastal adaptation options require are equally important. strategic planning, whereas few would occur The APF helps people answer the questions: autonomously. In addition, options to protect Impacts, Vulnerability against sea-level rise can be implemented ♦ What kind of policy instruments will reduce Coastal Zones in the both reactively and proactively, whereas most vulnerability to climate change? retreat and accommodation options are best ♦ What kind of policy decisions might be implemented in an anticipatory manner. To influenced by a project? date, the assessment of possible adaptation ♦ How might project results be introduced strategies in coastal zones has focused mainly onto the local, or national policy agenda? on protection. The range of appropriate options will vary among and within countries, and The APF not prescriptive; it is a flexible different socio-economic sectors may prefer approach in which the following five steps may competing adaptation options for the same be used in different combinations according to area. The existence of such a broad range of the amount of available information and the options is one of the reasons why adaptation to point of entry to the project: (1) defining project climate change is recommended to take place scope and design, (2) assessing vulnerability within the framework of integrated coastal zone under current climate, (3) characterizing management. The UNDP Adaptation Policy future climate related risks, (4) developing an Framework (APF) is one way countries have adaptation strategy, and (5) continuing the been able to identify and prioritize integrated adaptation process. The framework focuses on and cross-sector adaptation policies. the involvement of stakeholders at all stages. For example, the UAE is already well informed The UNDP Adaptation Policy Framework (APF) regarding its vulnerability under current provides useful guidance on designing and climate, and have invest time and resources in implementing projects that reduce vulnerability characterizing future risks to climate change. to climate change, by both reducing potential What remains is to define the scope and negative impacts and enhancing any beneficial design of future adaptation efforts, begin the consequences of a changing climate. Think of planning process for adaptation, and to start the APF as a structured approach to developing mainstreaming known risks to climate into all adaptation strategies, policies, and measures to aspects of the country’s 2030 visions, master ensure human development in the face of climate sector plans, and any other long term planning variability and change. The APF links climate process that, to date, has yet to adequately change adaptation to national development account for a changing climate. and environmental issues. The APF has been shown to be particularly applicable for and Developing an adaptation strategy for future effective in countries where the adaptation climate change requires a clear idea of key
53 objectives. At the broadest level, the overall zones (e.g. Kay et al., 1996; Pope, 1997). objectives of an adaptation strategy must fit In Abu Dhabi, where there are sophisticated within the development priorities of a country insurance markets that could cover climate risks, (for example, water security, food security insurance can have a positive or a negative role enhancement, action plans under multilateral in promoting adaptation to climate change and environmental agreements, etc). At a more any associated technology transfer. This may operational level, there are at least five happen directly via contacts with customers important objectives: or indirectly via the lobby institutions of the ♦ Increasing the robustness of infrastructure insurance industry. Technology underpins this designs and long-term investments; interaction, as improving data management and modeling capability give the insurance ♦ Increasing the flexibility and resilience industry more detailed information of both the of managed natural systems and social risks and opportunities that climate variability systems; and change present. However, more knowledge ♦ Enhancing the adaptability of vulnerable may benefit the insurance industry, but it does natural systems; not necessarily lead to overall social benefits. Clark (1998) argued that partnerships between ♦ Reversing trends that increase vulnerability governments and the insurance industry can (also termed “maladaptation”); and benefit both the industry and wider society in ♦ Improving societal awareness and terms of reduced exposure and maintain the preparedness for future climate change. long-term viability of the insurance industry. Developing an adaptation strategy also requires a vision that balances the need to reduce 5.6. Monitoring and evaluation climate change impacts with the constraints Effective evaluation of the effectiveness of inherent in national policymaking processes. adaptation measures implemented for Abu Ultimately, whatever the decisions reached Dhabi coastal areas will require a reliable set of regarding the most appropriate options and data or indicators, to be collected at some regular measures to reduce vulnerability, the packaging interval by means of an appropriate monitoring of those decisions into an adaptation strategy system. Indicators are a tool for reporting and streamlined for implementation will be communicating with decision makers and facilitated by policy coherence across sectors, the general public. They should have a range spatial scales, and time frames. of properties, including (i) a relationship to functional concepts, (ii) be representative and 5.5. Implementation responsive to relevant changes in conditions Once all options for coastal adaptation have and (iii) be easily integrated within a broader been considered and the most appropriate evaluation framework. Evaluation is an ongoing strategy has been selected and designed, process and the monitoring should be planned implementation of the strategy is the next accordingly. There is limited experience of such stage. An adaptation strategy can include the long-term monitoring, so in many situations it is unclear which are the most appropriate data application of technology, but this does not have or indicators (Basher, 1999). to be the case. In coastal zones, an adaptation strategy to sea-level rise can comprise one or For coastal physical systems, experience can be more options that fall under the three broad drawn from countries where the coast has been categories protect, retreat and accommodate monitored for long periods. In The Netherlands, (IPCC CZMS 1992). It should be noted that, in for instance, data on the position of high addition to the subdivision between protect, water have been collected annually for nearly retreat and accommodate, there are various a century and cross-shore profiles have been other ways to classify or distinguish between measured annually since 1963 (Verhagen, 1989; different adaptation strategies, both in generic Wijnberg and Terwindt, 1995). Observations of terms (e.g. Smit et al., 2000) and for coastal the natural evolution of the coast allow trends
54 Climate Change Impacts, Vulnerability & Adaptation to be estimated reliably and hence the impact of all levels. Figure 5-1 below shows examples of human interventions on the coast (breakwaters, adaptation activities for each of the five types of nourishment, etc.) to be evaluated. Additionally, adaptation that have thus been defined (from given the long-term nature of climate change, Klein et al, 2005). the adaptation policy process and implemented A key point is that adaptation to climate change strategies will need to make adjustments over is an ongoing and reiterative process that time as climate impacts manifest themselves. includes information development, awareness 5.7. Adaptation Strategies raising, planning, design, implementation and
monitoring. Reducing vulnerability requires Adaptation for & United Arab Emirates There are various ways to classify or having mechanisms in place and technologies, distinguish between adaptation options. expertise and other resources available to First, depending on the timing, goal and complete each part of this process. The mere motive of its implementation, adaptation can existence of technologies for adaptation does be either reactive or anticipatory. Reactive not mean that every vulnerable community, adaptation occurs after the initial impacts of sector or country has access to these options or climate change have become manifest, whilst is in a position to implement them. anticipatory (or proactive) adaptation takes In response to sea level rise, the literature place before impacts are apparent. A second and other countries have identified several distinction can be based on the system in which major coastal adaptation strategies: retreat, Impacts, Vulnerability Coastal Zones in the the adaptation takes place: the natural system resettlement, and improve coastal infrastructure (in which adaptation is by definition reactive) or like breakwaters and embankments to physically the human system (in which both reactive and protect existing infrastructure. The study of anticipatory adaptation are observed). Within Climate’s Long-range Impacts on Metro Boston the human system a third distinction can be (CLIMB) identified three overarching ways for based on whether the adaptation decision a city to adapt to anticipated climate changes, is motivated by private or public interests. including sea level rise (Kirshen et al., 2003). Private decision-makers include both individual The scenarios here have been adapted to the households and commercial companies, whilst UAE context in Table 5-1. public interests are served by governments at
Figure 5‑1. Types of Adaptation. (Klein et al, 2005)
55 Table 5‑1. Potential adaptation scenarios (Kirshen et al., 2003)
Scenario Policy Demographic Technology Title
Same as current Business as usual Present trends in region scenario of continued rate of penetration of continue. There are no sprawl of major green and innovative “Ride It Out” adaptation actions such metropolitan zones, technology by sector that ecosystems unable to mid-high population (e.g. Masdar Initiative); migrate inland growth rate; current however less concern on migration rates rising sea levels
Same as “Ride It Out” Same as “Ride It but replace and protect Out”; populations “Build Your systems as they fail may be forced to move Same as “Ride It Out” Way Out” (reactive adaptation); inland if protection ecosystems unable to systems fail “retreat” migrate inland
Higher rate of green Restrictions on technology penetration construction locations. than “Ride It Out”; Stronger bldg codes and “smart growth” natural hazard zoning. development such Emphasis on centralized Limited population “Green” that infrastructure and ‘climate proofed’ growth rate; is no longer built development; (proactive in vulnerable zones adaptation) (as identified by natural systems are allowed increasingly accurate to move inland inundation mapping)
56 Climate Change Impacts, Vulnerability & Adaptation 6. Conclusions and recommendations
Cross-sectoral and ministerial collaboration of the urban landscape may be fundamentally and partnerships are essential in addressing the different by then. In coastal cities, infrastructure challenges posed by climate change. To more and investment are obviously ongoing. Urban accurately assess vulnerability, the planning plans of grand high rises, rapid underground agencies in the UAE could work with city public transit infrastructure, modernized utility Adaptation for & United Arab Emirates planners who have current building footprint, pipelines, and anything else on the table, that property value and other important data likely (or hopefully) have a longer lifespan than sources, agencies with high resolution elevation the twenty-five to thirty years we may have datasets, as well as with those responsible for before our first critical time marker. the census and population studies that can help Work on adaptation so far has addressed spatially reference those populations the most the impacts of climate change, rather than vulnerable. A complimentary analysis focusing sufficiently addressing the underlying factors on the costs or financial losses to infrastructure that cause vulnerability to it. While there is a may be a logical next step in identifying where, significant push all around for adaptation to when, and how much areas will need investment be better placed in development planning, Impacts, Vulnerability for adaptation. Coastal Zones in the there is a missing step if vulnerability To better identify appropriate adaptation reduction is not considered central to this. strategies much more detailed data is required A successful adaptation process will require for sufficient mapping, for making financial or adequately addressing the underlying causes infrastructural decisions, or for model potential of vulnerability. A sustainable adaptation population movements given a ‘worst case process appears to first require adjustments scenario’. It is likewise important to improve in policies, institutions and attitudes that scientific understanding around extreme establish enabling conditions, and second be events and the probability of cyclones like Gonu accompanied by eventual technological and becoming a recurring event. Cyclone and storm infrastructural changes. surge modelling were outside the scope of this study, except to say that if the coastal cities In thinking towards future sea level rise, anticipate a 3m wave surge, the vulnerable we usually identify 2050 as the first critical areas are the same regardless of whether it’s benchmark, after which most quasi-protected, gradually or abruptly inundated. This analysis or at least non-island state, societies should is a broad assessment, given available data, that start to worry. Past conception of invincibility suggests area for future studies—particularly to coastal events are no longer supported by those areas who find themselves vulnerable to science. Southeast Asia, and low lying states like only 1m of sea level rise which we may see by Bangladesh are already planning for migrating the end of the century. A second consideration millions of people to higher ground. The UAE, is the complexity of shoreline systems. As a first at least those Emirates that border the Arabian cut inundation study we have stayed away from Gulf, have seemed somewhat protected from modelling how the shoreline and ecosystems will the ravages of Indian Ocean cyclones. However physically respond to rising sea levels, however, it too is a low-lying nation. The majority of an accurate shore-dynamics model that include the coastline and coastal ecosystems find topographic data of even up to 10cm vertical themselves within 0-5 meters elevation above resolution as well as eco-system specific habitat mean sea level. migration research would help in this regard. Given the intersection of Abu Dhabi’s new and planned infrastructure with increasing climate While we may not be able to pinpoint exactly risks, the current trajectory could unwittingly be when to expect one meter gradual rise in sea headed towards disaster if it does not adequately level, we do know that it may be sooner than take into account known climate risks into most scientists ever thought possible. Much
57 plans. If the planet were to reach any kind of Adaptation Strategy (use Table 5-1). As has global tipping point, whether from quickened been experienced time and time again in many ice-sheet melt, or high concentrations of places across the world, Ride it Out may no carbon in the atmosphere and ocean warming longer be an option. Build Your Way Out may both we could start to witness the abrupt an option for those with sufficient resources it disruption of local (and previously somewhat is not a viable long-term response. The UAE can predictable) weather patterns and coastal continue to lead by example on climate change dynamics. The uncertainty of ‘when’ and ‘to by choosing the “Green” adaptation strategy, a what extent’ are we really vulnerable placates strategic response that calls for proactive and many into a ‘wait and see’ mentality—trending innovative thinking, and a coordinated effort towards a “Ride it out” or “Build Your Way Out” across ministries and sectors.
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60 Climate Change Impacts, Vulnerability & Adaptation Assessment Report of the Intergovernmental mineralizsation in Sabkhat , in Barth and Böer” Panel on Climate Change [Solomon, S., D. Qin, (eds) Sabkha Ecosystems, pp. 299-302. M. Manning, Z. Chen, M. Marquis, K.B. Averyt, Preliminary Review of Adaptation Options for M.Tignor and H.L. Miller (eds.)]. Cambridge Climate-Sensitive Ecosystems and Resources, University Press, Cambridge, United Kingdom U.S. Climate Change Science Program And the and New York, NY, USA. Subcommittee on Global Change Research June Mosaic Mapping Systems, Inc. (2001). A White 2008. Paper on LIDAR Mapping. Retrieved 28 February Pugh, D (2004). Changing Sea Levels: Effects of
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Nicholls and Klein, (2005). Climate change To Five Metres Of Sea Level Rise Journal of Risk and coastal management on Europe’s coast..” Research, Volume 9, Number 5, July 2006 , pp. 467- Managing European Coasts: Past, Present and 482(16) Future. Riegl, B. (2001). “Inhibition of reef framework by Nicholls, R., and Tol, R. (2006) Impacts and frequent disturbance: Examples from the Arabian responses to sea-level rise: a global analysis of Gulf, South Africa, and the Cayman Islands.” the SRES scenarios over the twenty-first century. PALAEO. 175, 79-101. Philosophical Transactions of the Royal Society, Riegl, B. (2002). “Effects of the 1996 and 1998 A, 364 (1841): 1073-1095. positive sea-surface temperature anomalies on NOAA (2007). What is LIDAR beach mapping? corals, coral diseases and fish in the Arabian Gulf Retrieved 28 February 2008 from http://www.csc. (Dubai, UAE).” Marine Biology. 140 pp. 29-40. noaa.gov/products/nchaz/htm/intro.htm Riegl, B. (2003). “Climate change and coral reefs: Permanent Service for Mean Sea Level (2008) different effects in two high-latitude areas (Arabian “PSMSL Monthly and Annual Mean Sea Level Gulf, South Africa)” Coral Reefs. 22 pp. 433-446. Station Files.” Available online: http://www.pol. Riegl, R. (2007) “Extreme Climatic Events and ac.uk/psmsl/psmsl_individual_stations.html, see Coral Reefs: How Much Short-Term Threat from 482/006. Global Change?” in Arason, B. (ed.) Geological Phillips, R. (2002) “Seagrasses of the Arabian Approaches to Coral Reef Ecology. Springer: New Peninsula Region, with particular reference to York, 315-341.
61 Royer, J, Chauvin, F, Timbal, B., Araspin, P., and UAE National Media Council, (2008). United Arab Grimal D. (1998) “A GCM study of the impact Emirates Yearbook 2008: Infrastructure. Available of greenhouse gas increase on the frequency of from http://www.uaeinteract.com/uaeint_misc/ occurrences of tropical cyclones” Climate Change, pdf_2008/English_2008/eyb6.pdf vol.38, pp.307-343. UofA (University of Arizona) (2003). Climate Saenger, P. and Blasco, F. (2000). “The mangrove Change and Sea Level: Technical Description for resources of the UAE with particular emphasis Maps of Susceptible Areas. . Retrieved 28 February on those of the Abu Dhabi Emirate.” 2nd Arab 2008 from http://www.geo.arizona.edu/dgesl/ International Conference and Exhibition on research/other/climate_change_and_sea_level/sea_ Environmental Biotechnology in Abu Dhabi. level_rise/sea_level_rise_technical.htm. Coastal Habitats. Abu Dhabi, 8-12 April 2000. USGS (2003). Shuttle Radar Topography Mission Saenger, P., Blasco, F., Auda, F., Aizpuru, M., (SRTM)Fact Sheet 071-03. Retrieved 28 February Youssef, A. and Loughland, R. A. Loughland, R. 2008 from: http://mac.usgs.gov/isb/pubs/factsheets/ A., Muhairi, F. S. Al, Fadel, S. S., Mehdi, A. M. Al fs07103.html and Hellyer, P. (eds) (2004) Mangrove Resources of the UAE with particular emphasis on those of Abu Vaidya, S. (2007) “Gulf states on Gonu alert.” Dhabi Emirate. Marine Atlas of Abu Dhabi pp. 58- Saffir-Simpson Hurricane Scale Table, FEMA 69. Emirates Heritage Club , Abu Dhabi, UAE. Available online: http://www.gulfnews.com/
Sheppard, C., and Loughland, R. (2002). “Coral articles/07/06/05/10130289.html mortality and recovery in response to increasing Webster, P. Holland, G. Curry, J. & Chang, H. (2005) temperature in the southern Arabian Gulf.” “Changes in Tropical Cyclone Number, Duration, Aquatic Ecosystem Health and Management. 5(4) and Intensity in a Warming Environment.” Science pp.1-8. 309, 1844–1846 Short F. Neckles H (1999) “The effects of global Wigley, T.M.L. and S.C.B. Raper (1987) “Thermal climate change on seagrasses.” Aquatic Botany, expansion of sea water associated with global Volume 63, Number 3, 1 April 1999 , pp. 169- warming.” Nature 357 pp. 293-300. Available online: 196(28) http://sedac.ciesin.org/mva/WR1987/WR1987.html Stanton and Ackerman (2007). Florida and Climate Change: The Costs of Inaction. Available online: Wu, S. and Najjar, R. (2000). Mapping sea-level rise. http://ase.tufts.edu/gdae/Pubs/rp/FloridaClimate. Retrieved 28 February 2008 from http://www.cara. html psu.edu/about/mappingsealevelrise.asp.
Stoffers and Ross, (1979); Sarnthein, (1972); Yohe, G., Malone, E. , Brenkert, A., Schlesinger, Reynolds, (1993) as referenced in ADEA coastal M. , Meij, H. Xing, X. and Lee, D. .( 2006). A and marine report Synthetic Assessment of the Global Distribution of Vulnerability to Climate Change from the IPCC Sultan et al., (1995) S.A.R. Sultan, F. Ahmad, N.M. Elghribi and A.M. Al-Subhi, An analysis of Arabian Perspective that Reflects Exposure and Adaptive Gulf monthly mean sea level, Continental Shelf Capacity. Palisades, New York: CIESIN (Center for Research 15 (1995), pp. 1471–1482 International Earth Science Information Network), Columbia University. Retrieved 28 February 2008 Titus, J., and Richman, C. (2001) Maps of Lands from: http://ciesin.columbia.edu/data/climate/ Vulnerable to Sea Level Rise: Modeled Elevations index.html. along the U.S. Atlantic and Gulf Coasts. Retrieved 28 February 2008 from: http://epa.gov/climatechange/ Zimmerman and Livingston, 1976; Bay, 1984; Averza effects/coastal/slrmaps_vulnerable.htmlThieler, E., and Almodovar, 1986; Dennison and Alberte, 1986; Williams, J., Hammar-Klose, E. (2007). National Dawes and Tomasko, 1988; Orth and Moore, 1988; Assessment of Coastal Vulnerability to Sea Level see also the review by Duarte, 1991) as referenced Rise. USGS Woods Hole Field Center. Retrieved 28 in Short, F, Neckles, H. (1999) “The effects of global February 2008 from: http://woodshole.er.usgs.gov/ climate change on seagrasses” Aquatic Botany, 63 project-pages/cvi/. (3), pp. 169-196.
62 Climate Change Impacts, Vulnerability & Adaptation 8. Glossary
Adaptation: Adjustment in natural or and “climate variability” attributable to natural human systems in response to actual or causes. expected climatic stimuli or their effects, Climate hazards: Climatic hazards are threats which moderates harm or exploits beneficial to a system, comprised of perturbations and opportunities. Various types of adaptation stress (and stressors), and the consequences can be distinguished, including anticipatory, they produce. A perturbation could be a major autonomous and planned adaptation. & Adaptation for &
spike in pressure (e.g., a tidal wave or hurricane) United Arab Emirates Adaptive Capacity: The ability of a system to beyond the normal range of variability in which adjust to climate change (including climate the system operates. Perturbations commonly variability and extremes) to moderate potential originate beyond the system or location in damages, to take advantage of opportunities, or question. Hazards can include latent conditions to cope with the consequences. (IPCC) that may represent future threats and can be Adaptive Management: Adaptive management single, sequential or combined in their origin seeks to aggressively use management and effects. Each hazard is characterized by its intervention as a tool to strategically probe location, intensity, frequency and probability. the functioning of an ecosystem. Interventions Climate Model: commonly thought of as a are designed to test key hypotheses about the numerical or mathematical representation of Impacts, Vulnerability functioning of the ecosystem. This approach the physical, chemical and biological properties Coastal Zones in the is very different from a typical management (atmosphere, ocean, ice and land surface) of a approach of ‘informed trial-and-error’ which climatic system, which incorporates scenarios uses the best available knowledge to generate a (coherent internally consistent and plausible risk-averse, ‘best guess’ management strategy, descriptions of a possible forthcoming states which is then changed as new information of the world; Carter et al, 1994) allowing for the modifies the ‘best guess’. Adaptive management generation of future predictions (Santer et al., identifies uncertainties, and then establishes 1990). methodologies to test hypotheses concerning Climate variability: Climate variability refers to those uncertainties. It uses management as a variations in the mean state and other statistics tool not only to change the system, but as a tool (such as standard deviations, the occurrence of to learn about the system. It is concerned with extremes, etc.) of the climate on all temporal the need to learn and the cost of ignorance, and spatial scales beyond that of individual while traditional management is focused on weather events. Variability may be due to the need to preserve and the cost of knowledge. natural internal processes within the climate (www.resalliance.org/565.php) system (internal variability), or to variations Climate change: Climate change refers to a in natural or anthropogenic external forcing statistically significant variation in either the (external variability) (IPCC, 2001). mean state of the climate or in its variability, Climate threshold: The point at which external persisting for an extended period (typically forcing of the climate system, such as the decades or longer). Climate change may be due increasing atmospheric concentration of to natural internal processes or external forcings, greenhouse gases, triggers a significant climatic or to persistent anthropogenic changes in the or environmental event which is considered composition of the atmosphere or in land use unalterable, or recoverable only on very long (IPCC, 2001). Note, however, that the United time-scales, such as widespread bleaching Nations Framework Convention on Climate of corals or a collapse of oceanic circulation Change (UNFCCC) defines climate change as: systems (IPCC, 2007). “a change of climate which is attributed directly or indirectly to human activity that alters the Climate change scenarios: coherent and composition of the global atmosphere and internally-consistent descriptions of future which is in addition to natural climate variability climate given certain assumptions about the observed over comparable time periods”. The growth of the emissions of greenhouse gases and UNFCCC thus makes a distinction between about other factors that may influence climate “climate change” attributable to human in the future. The uncertainties associated with activities altering the atmospheric composition, the modeling of future climate scenarios have
63 been divided by the Hadley Centre into three due to sea-level rise) (IPCC, 2007). broad categories: (1) emissions uncertainty; (2) SRES: The storylines and associated population, natural climatic variability; and (3) modeling GDP and emissions scenarios associated with uncertainty (UKCIP). the Special Report on Emissions Scenarios Climate Impact Assessment: the practice of (SRES) (Naki enovi et al., 2000), and the resulting identifying and evaluating the detrimental and climate change and sea-level rise scenarios. Four beneficial consequences of climate change on families of socio-economic scenario (A1, A2, B1 natural and human systems (IPCC). and B2) represent different world futures in two Impacts of climate change: The effects of distinct dimensions: a focus on economic versus climate change on natural and human systems. environmental concerns, and global versus Depending on the consideration of adaptation, regional development patterns (IPCC, 2007). one can distinguish between potential impacts Thermal expansion: In connection with sea- and residual impacts: level rise, this refers to the increase in volume ♦ Potential impacts: all impacts that may occur (and decrease in density) that results from given a projected change in climate, without warming water. A warming of the ocean leads to considering adaptation. an expansion of the ocean volume and hence an ♦ Residual impacts: the impacts of climate increase in sea level. (IPCC, 2007). change that would occur after adaptation. Thermohaline circulation (THC): Large- See also aggregate impacts, market impacts, scale, density-driven circulation in the ocean, and non-market impacts. caused by differences in temperature and Mitigation: An anthropogenic intervention salinity. In the North Atlantic, the thermohaline to reduce the sources or enhance the sinks of circulation consists of warm surface water greenhouse gases (IPCC, 2007) flowing northward and cold deepwater flowing southward, resulting in a net poleward transport No-regrets adaptation measures: fail-safe of heat. The surface water sinks in highly adaptation options whose benefits, such as restricted regions located in high latitudes. reduced energy costs and reduced emissions Also called meridional overturning circulation of local/regional pollutants equal or exceed their cost to society, excluding the benefits of (MOC). (IPCC, 2007). climate change mitigation. They are sometimes United Nations Framework Convention on knows as “measures worth doing anyway”. For Climate Change (UNFCCC): The Convention example an infrastructure no-regret option was adopted on 9 May 1992, in New York, would increase the durability and longevity of a and signed at the 1992 Earth Summit in building to climate variability over time. (IPCC, Rio de Janeiro by more than 150 countries http://www.ipcc.ch/pdf/climate-changes- and the European Community. Its ultimate 1995/2nd-assessment-synthesis.pdf) objective is the ‘stabilization of greenhouse gas Sea-level rise: An increase in the mean level of concentrations in the atmosphere at a level the ocean. that would prevent dangerous anthropogenic interference with the climate system’. It ♦ Eustatic sea-level rise is a change in global average sea level brought about by an increase contains commitments for all Parties. Under the in the volume of the world ocean. Convention, Parties included in Annex I aim to return greenhouse gas emissions not controlled ♦ Relative sea-level rise occurs where there is a by the Montreal Protocol to 1990 levels by the local increase in the level of the ocean relative year 2000. The Convention entered in force in to the land, which might be due to ocean rise March 1994 (IPCC, 2007). and/or land level subsidence. In areas subject to rapid land-level uplift, relative sea level can Vulnerability: Vulnerability is the degree to fall. (IPCC, 2007) which a system is susceptible to, and unable to cope with, adverse effects of climate Sensitivity: Sensitivity is the degree to which a system is affected, either adversely or beneficially, change, including climate variability and by climate variability or change. The effect may extremes. Vulnerability is a function of the be direct (e.g., a change in crop yield in response character, magnitude, and rate of climate to a change in the mean, range or variability of change and variation to which a system is temperature) or indirect (e.g., damages caused exposed, its sensitivity, and its adaptive by an increase in the frequency of coastal flooding capacity (IPCC, 2007).
64 Climate Change Impacts, Vulnerability & Adaptation To calculate areas inundated by land use category: Spatial Analyst Tool “Intersect” Floodfil Output File with Environment Agency’s landuse GIS layers
+ = 65
Impacts, Vulnerability & Adaptation for Coastal Zones in the United Arab Emirates Example Map includes: Domestic Supply Well Fields, Farms, Forest and Urban Greening 66 Climate ChangeImpacts,Vulnerability &Adaptation Annex 1: Elevation Data Sensitivity Analysis
Introduction: the influence of digital against the global, GTOPO30 data set and in elevation models (DEMs) on models of sea level Honduras the compared the SRTM against rise. cartographically derived TOPOGRID at
1 Adaptation for & Topographic information is integral to analyses 1:50,000 . SRTM is vast improvement on global United Arab Emirates in many fields of research including ecology, DEM (GTOPO), and care should be taken hydrology, agriculture, geology and others. With when interpolating SRTM holes with GTOPO technological advances, many researchers have data. The researchers found that based on transitioned to using digital elevation models their analysis of specific locations that SRTM (DEMs) for computer-based processing. A DEM data are was accurate to +/- 16-meters. After is merely numerical representation of surface comparing SRTM values against an existing elevations over a region of terrain (Cho and GPS database of elevation points, the team Lee, 2001). There are multiple ways to derive found that SRTM values were close to GPS DEMS- from time-consuming digitization values 80% of the time. On average, the SRTM processes of paper quadrangle maps to shuttle differed from the TOPOGRID by 8 meters and Impacts, Vulnerability Coastal Zones in the radar missions. A body of literature has emerged from the GPS points by 20meters. around both assessments based on DEM source The researchers found that terrain heavily (Hodgson et al., 2003) as well as the impact influenced the elevation difference between the of DEM resolution on the results of research DEMs. In addition, as hydrologic properties projects. are inherently tied to terrain, the quality of DEMs are used in an array of projects. Elevation terrain data affects the accuracy of hydrologic data contributes to site suitability analysis for models. Researchers agreed that the 1:10,000 property development, transportation networks cartographic derived DEM is the best scale and other infrastructural developments, as especially when dealing with hydrological well as identifying ecosystem and biodiversity models; however, high-resolution cartographic conservation or migration. Researchers also data exists for few areas in tropical countries. use coastal DEMs to identify the extent of Even in countries with a strong tradition of areas vulnerable to sea level rise and storm cartographic mapping, like the US, age of surges. As scientists have begun realizing that cartographic maps on which national DEMs are the pace of climate change is much faster than based adds another dimension to the accuracy initially expected, there is an urgent need for of models; for example, 1950s contour lines in more accurate modeling of regional and abrupt one region may not accurately reflect more sea level rise, coastal inundation of flood plains recent land changes. from storm surges, and a range of other climate change impacts. Typically, in tropical countries, the SRTM overestimates for northeast facing slopes and DEM Comparisons underestimates for southwest facing slopes; an occurrence that correlates with shuttle Jarvis et al. (n.d.) explored different DEM flight path directions. In general, the SRTM through a serious of case studies in Ecuador, data tended to have more surface detail Honduras, and Columbia. In Ecuador, the and roughness than the TOPOGRID. For researchers analyzed the SRTM DEM hydrological modeling, the SRTM performs well
1The cartographically derived maps were digitized by the Centro International de Agricultura Tropical (CIAT). The entire country, 280 topographic sheets and an additional 250 maps from the national forestry commission that needed rectifying were digitized at a 1:50,000 scale (with 100m contour lines, and 10m contour lines <100m above sea level) . The result was a 90-meter resolution TOPOGRID DEM to match the SRTM DEM (Jarvis et al, n.d.).
67 but it is definitely better to use high-resolution determining its vulnerability to sea level rise, a maps like cartographic maps at 1:25,000 or key impact of climate change on coastal areas. smaller to improve accuracy (Jarvis et al., n.d.). Most sea level rise (SLR) scenarios estimate Other authors point out that coarser resolution 50-100cm inundation over the next century DEMs ignore details of surface characteristics depending on the region. In modeling sea level like steep slopes (Dong et al., n.d.) and because rise based on elevation, following components the values are often represented as integers (at of a DEM are in question. least in USGS DEMs), modeled slope for areas Data source and method of collection of limited reliefs would even show “artificial Vertical and horizontal resolution jumps” in slopes over shorter distances (Hodgson et al., 2003; Carter, 1992). Aspect Slope Cho and Lee (2001) and Dong et al. (n.d.) confirm the emphasis in Jarvis et al. (n.d.) Terrain is another important determinant of with respect to the influence of DEM accuracy DEM accuracy, particularly for DEMs derived on hydrological models. Cho and Lee’s paper from SRTM and LiDAR data. Jarvis et al. (n.d.) exploring sensitivity considerations found found that SRTM overestimates for northeast that with a 1:24,000 DEM (7.5 minute), their facing slopes and underestimates for southwest hydrologic model revealed higher runoff volumes facing slopes (correlating with flight path which the 1:250,000 (1 degree) DEM flattens the directions). Others highlighted the challenge of watershed’s slope yielding delayed stream flow modeling areas of limited relief using elevation and underestimating runoff and erosion. The intervals of 1 meter, or even 10-50 meter jumps two credited the finer resolution of 7.5-minute as many do, and the inappropriateness of such dataset, with yielding increased average slope data for limited relief coastal areas vulnerable and thus higher runoff when the simulation was to sea level rise. run. Dong et al., (n.d.), in their comparison of Synthetic Aperture Radar (InSAR), LiDAR, The challenge, to date, as we noted in the body and photogrammetrically derived DEMs (Noble of the report has been estimating vulnerable zones based on these <1 meter SLR scenarios et al., n.d.), similarly found that the main while using topographic maps and digital differences in topographic attributes revealed elevation models whose vertical resolutions during their research were in river channels, range from 1.5 to 10 to 100 meters. Studies have having implications for hydrological processes. used the best available data and interpolation Their paper highlights importance of accurate methods to come with broad estimations of terrain modeling on hydrologic simulations on the Broadhead watershed in New Jersey; their places that may be at risk; with the exception of conclusions can extend to coastal flood plains highly accurate (and highly expensive) -- LiDAR and would affect storm surge and sea level rise data have errors in the range of +/- 0.3 meters-- modeling. the accuracy of these estimations will remain a problem. Broad estimations can, however, point Conclusion to areas for more precise studies and can be used in recommendations for investing in select Elevation of coastal land is a critical factor in area of LiDAR data.
68 Climate Change Impacts, Vulnerability & Adaptation Annex 2: Inundation maps
3. Urban Vulnerability: Abu Dhabi (All Scenarios) 69
Figure A2-1 Baseline map, Abu Dhabi
Impacts, Vulnerability & Adaptation for Coastal Zones in the United Arab Emirates 70 Climate ChangeImpacts,Vulnerability &Adaptation
Figure A2-2 1 meter sea level rise, Abu Dhabi 71
Figure A2-3 3 meters sea level rise, Abu Dhabi
Impacts, Vulnerability & Adaptation for Coastal Zones in the United Arab Emirates Figure A2-4 9 meters sea level rise, Abu Dhabi (Infrastructure impacts)
A2- 5 9 meters sea level rise, Abu Dhabi (ecosystem impacts).
72 Climate Change Impacts, Vulnerability & Adaptation 73
Figure A2-6 1,3,9 meters sea level rise, Dubai
Impacts, Vulnerability & Adaptation for Coastal Zones in the United Arab Emirates 74 75 List of Tables Page
Table 2‑1. Abu Dhabi Emirate groundwater reserves estimate from GWAP (GTZ, 2005a)...... 81 Table 2‑2. Western Region potable water consumption from Mirfa and Sila desalination plants.(2003)...... 81 Table 2-3. Total water consumption in Abu Dhabi for the year 2003 ...... 84 Table 3‑1. Summary of GCM outputs for Abu Dhabi ...... 93 Table 3‑2. Shwaib diversion structure ...... 98 Table 4‑1. Irrigated Ha from GIS layers ...... 103 Table 4‑2. Municipal and industrial water demand, 2003 ...... 105 Table 4‑3. Total supplies represented by the WEAP model ...... 106 Table 4‑4. Irrigation coefficients for the five represented crops/plants...... 107 Table 4‑5. Comparison of historical estimated and WEAP modeled demands ...... 109 Table 4‑6. 5 GCM outputs projected maximum/minimum changes...... 111 Table 4‑7. Summary of climate changes included in WEAP modeled scenarios...... 112 Table 4‑8. Summary of scenarios used in Abu Dhabi Emirate climate change analysis ...... 115 Table 6‑1. Adaptation options for water supply and demand ...... 125 Table A1-1. Abu Dhabi Emirate groundwater reserves estimate from GWAP (GTZ, 2005a)...... 131 Table A1-2. Demand site assumptions...... 131 Table A1-3. Catchment site assumptions...... 132 Table A2-1. Summary of 36 emission scenario and 17 GCM options...... 135 Table A2-2. Emission scenarios and GCMs used for the UAE...... 135 Table A2-3. Annual average maximum change, 2050 and 2100...... 138 Table A2-4. Annual average minimum change, 2050 and 2100...... 138 Table A2-5. Summary of GCM Output Range for Abu Dhabi...... 138 Table A2-6. Summary of climate changes included in WEAP modeled scenarios...... 138
List of Figures Page
Figure 2‑1. Percentage of total supply ...... 81 Figure 2‑2. Regional divisions used with indications of irrigated areas, and Eastern domestic well fields (Western domestic demand is met entirely with desalination) ...... 82 Figure 2‑3. Changes in groundwater levels at Al Ain over the last 4,500 years ...... 83 Figure 2-4.Summary of total sector consumption by region (2002)...... 84 Figure 2‑5. GDP and bulk per capita water use in Abu Dhabi ...... 85 Figure 2‑6. Expansion and plateau of Abu Dhabi Citizens Farms, 1996-2005 ...... 87 Figure 3‑1. Global average temperature and CO2 trends (Karl and Trenberth 2003) ...... 89 Figure 3‑2. Relative radiative forcing attributable to human activities ...... 90 Figure 3‑3. Historic observed global average temperatures, and projected global average temperatures based on various projections of global CO2 concentrations...... 90 Figure 3‑4. Statistical summary of projected patterns of precipitation change from multiple General Circulation Models for December, January and February (left) and June, July, and August (right)...... 92 Figure 3‑5a. Probability Density Function -b1_temp_2050_annual...... 94 Figure 3‑5b. Probability Density Function -a1b_temp_2050_annual...... 94 Figure 3‑5c. Probability Density Function - b1_precip_2050_annual...... 95 Figure 3‑5d. Probability Density Function - a1b_precip_2050_annual...... 95 Figure 3‑6. Maximum and minimum projected temperature and rainfall change ...... 96 Figure 3‑7: Projected monthly temperature change, 2050 and 2100 ...... 97 Figure 3‑8: Projected monthly rainfall change, 2050 and 2100 ...... 97 Figure 4‑1. A WEAP schematic of the Abu Dhabi Emirate ...... 103 Figure 4‑2. Eastern region supply and demand representation in WEAP...... 106 Figure 4‑3. The directory tree in WEAP, suggesting the data structure used to represent M&I demands (‘Red Dots’) and Irrigation Demands (“Green Dots”) ...... 106 Figure 4‑4. Al Ain “average” monthly rainfall over the period 1994-2005 ...... 108 Figure 4‑5. WEAP model estimates of total annual demand (left axis) and potential evapotranspiration (solid line, right axis)...... 110
76 Climate Change Impacts, Vulnerability & Adaptation Page
Figure 4‑6. WEAP estimates of total annual water supply used to meet the demands ...... 110 Figure 4‑7. The average monthly temperature for the Middle-of-the-Road (MOR) scenario ...... 113 Figure 4‑8. Total annual precipitation for the three climate change scenarios ...... 113 Figure 5‑1. Total annual water demand estimates for the nine scenarios ...... 117 Figure 5‑2. Water demands by sector for the Optimistic Scenario with Adaptation and with and without climate change ...... 118 Figure 5‑3. Supply allocation for Optimistic Scenario with Adaptation ...... 119 in Abu Dhabi Figure 5‑4. Total unmet demand for the Optimistic and Pessimistic Adaptation for & Scenarios with Adaptation (1.2 and 2.2, respectively)...... 120 Figure 5‑5. Fresh and brackish groundwater storage over the study horizon for all three optimistic scenarios ...... 121 Figure 6‑1. Summary of total water demand for the Optimistic and Pessimistic Scenarios ...... 124 Figure A1‑1. Overview Map...... 128 Figure A1‑2. Map of Abu Dhabi key Water Supply / Demand...... 129 Figure A1‑3. Sources and Users of Water in Abu Dhabi Emirate...... 130 Figure A2-1. Temperature change (ºC) in 2050...... 136 Figure A2-2. Temperature change (ºC) in 2100...... 136 Impacts, Vulnerability Water Resources Figure A2-3. Precipitation change (ºC) in 2050...... 137 Figure A2-4. Precipitation change (ºC) in 2100...... 137
List of Acronyms
ADWEA Abu Dhabi Water and Electricity MA Millennium Ecosystem Assessment Authority MED Multi Effect Distillation ADE Abu Dhabi Emirate MGD million gallons per day APF Adaptation Policy Framework M&I municipal and industrial AR4 Fourth Assessment Report Mm3/yr million cubic meters per year of the IPCC MOR Middle-of-the-Road Bm3 billion cubic meters MSF Multi Stage Flash CO carbon dioxide 2 PET Potential evapotranspiration DSS Decision Support System Ppmv parts per million by volume ENSO El NiÑo Southern Oscillation RF Radiative Forcing FAO United Nations Food and RH relative humidity Agricultural Organization SRES Special Report on Emissions GCM global climate models Scenarios GDP gross domestic product TDS total dissolved solids GEF Global environment facility TSE treated sewage effluent GHG green house gas (emissions) UKCIP United Kingdom’s Climate Impacts GIS Geographical Information System Programme gpd gallons per day UNFCCC United Nations Framework IPCC Intergovernmental Panel on Convention on Climate Change Climate Change USGS US Geological Service Kc crop coefficient WEAP Water Evaluation and Planning model 3 Km cubic kilometers WGII Working Group II of the IPCC l/c/day liters per capita per day W/m2 watts per square meter 3 m /d cubic meters per day WMO World Meteorological Organization LOSU Level of Scientific Understanding UAE United Arab Emirates
77 1. Introduction
The Abu Dhabi Emirate (ADE), is one of the capita consumption is increasing even more at seven Emirates that comprise the United Arab roughly 8%. Emirates (UAE), which occupies an area of At present, water for domestic and industrial 67,340 km², almost 80% of the total area of UAE. uses is largely derived from desalinization, The Emirate has a hyper-arid climate with less provided by the Abu Dhabi Water and Electricity than 100 mm/yr of precipitation, a very high Authority (ADWEA). Left unchecked, rising potential evaporation rate (2-3m / yr), a very domestic consumption will increasingly be met low groundwater recharge rate (<4% of total by desalinated supplies. annual water used) and no reliable, perennial surface water resources. Surface waters that Over the past few decades there have been are present, resulting from flash flooding in efforts to further develop groundwater recharge wadis, more often damage planted areas rather zones in the western portion, near the Oman than benefit them. Mountains and Al Ain. Recharge zones and storage dams have been developed along wadi Despite this paucity of renewable freshwater, drainages, and a rainfall augmentation program the ADE has experienced explosive population is being developed (Abdulla Mandoos- Director, and economic growth, with GDP and population Center for Meteorology and Seismology, personal growth rates exceeding 8% per annum (CIA, communication). Exploration efforts have 2008). Prior to statehood, most of the population included the Groundwater Research (USGS/ of the region was supported by groundwater NDC, 1994) and Groundwater Assessment from shallow wells and the traditional Falaj Programs (GTZ et al. 2005), conducted near system of groundwater collection systems and the Liwa Crescent. Found to its north was hand dug tunnels. Most of these systems have groundwater storage estimated at about 100 since dried, and in their place is an extensive Bm3, of which 16 Bm3 is fresh (as reported by system of boreholes that mine the region’s Brook et al. by the USGS/NDC, 1993). Practically, underlying groundwater supplies. there is no modern day groundwater recharge Most socio-economic growth has been in the western aquifers of Abu Dhabi. Although supported by these groundwater resources, substantial groundwater reserves have been albeit most are brackish and saline in nature. discovered, the majority of these were recharged Despite rapid population and economic some 6,000 to 9,000 years before present and so growth and limited freshwater supplies, the the fresh groundwater water lenses are fossil in bulk of freshwater continues to be used by the nature (Wood and Imes, 1995). agricultural, forestry, and plantation sectors, Two major studies, GWRP (USGS/NDC, 1993) with some estimates that these demands are and GWAP (GTZ et al, 2005), independently more than 80% of the total annual water use of estimated the groundwater stored through the 3.4 billion m3 (Bm3). Amenity planting, forestry Abu Dhabi Emirate, with estimates of total and agriculture farms are expanding irrigated groundwater reserves of 253 Km³ (7% fresh, areas with few constraints on water use until 93% brackish) and the GWAP total estimate recently. Over the past few decades there have of 640 Km³ (79.4% saline). The GWAP analysis been government programs that have ‘greened used a substantially higher salinity threshold the desert’ and subsidized a growing agricultural of to 100,000 mg/l TDS, whereas the GWRP sector that has meant much greater water use included groundwater salinity threshold of less and increased reliance on non-traditional water than 15,000 mg/l TDS. The most striking feature sources like desalinization. of both estimates is that the amount of fresh groundwater remaining in storage is very small, Municipal water demand also contributes to ranging from 2.6% to 7% of the total. scarcity concerns, as Emirate-wide population growth is roughly 6% per year, and slightly According to the GWAP assessment more than higher in Abu Dhabi City and Al Ain while per three-quarters (12.5 km³) of the fresh water
78 Climate Change Impacts, Vulnerability & Adaptation in storage occurs in the Liwa lens and only climate, opportunities for reuse are small and about 4 km³ in the Eastern region. Moreover, climate variability and change could increase according to the GWRP assessment, at current the consumptive demands of these uses. This groundwater abstraction rates, it is projected brings into question the long-term sustainability that the fresh and brackish groundwater of these water supplies and how future water resources will be depleted in 50 years. Long- demands will be met. term strategies for water planning, management Utilizing water resources decision support tools, and conservation are not yet in place. Water this study focuses on quantification of potential projects are usually massive and require high future water stress in the region by combining in Abu Dhabi investments while the economic returns of are Adaptation for & generally low as compared to other investment climate model outputs, projected water sectors. Efforts launched to date have been budgets, and socioeconomic information. The hindered by the shortage of available funds for country's existing climatic context has already water development and conservation projects. demanded innovation in how water resources are managed. A baseline water demand modeling Water resource management typically implicates framework is developed for the Abu Dhabi numerous and diverse socio-economic sectors Environment Agency that could be used to including agriculture, human and ecosystem assess future demand and supply requirements, health, coastal zones, and infrastructure. Impacts, Vulnerability and look at the overall sustainability of the sector Water Resources The case is no different for the UAE, where under future stressors, including population, any changes in climate conditions, such as economic growth, and climate change. Program temperature and precipitation, can place further like the GTZ and Groundwater Assessment stress on already severely limited groundwater Project developed comprehensive inventory and surface water resources. Potential changes and database of the groundwater resources in climate are then a cause for serious concern throughout Abu Dhabi. and careful consideration and planning. This project relies on these databases, by Because groundwater resources in Abu Dhabi making an ADE-wide water supply and demand are derived from fairly deep geologic structures, model that harvests these data held at the and those near the coast are already highly Environment Agency of Abu Dhabi (EAD). A saline, the impact of rising sea levels along Water supply/demand model was built using the Arabian Gulf likely will not appreciably impact the groundwater quality over the next the Water Evaluation and Planning (WEAP) century. Rather, the bigger concern with regard decision support system, and this used to to climate change appears to be the potential assess potential climate change impact and for even larger growth in water demand that adaptation options for the ADE. could be superimposed on the already explosive We have found that climate change would have demand presently stressing these scarce a marginal impact on water resources relative groundwater resources. For example, while to the bigger socio-economic drivers of per- summer temperatures are already extreme capita demand, assumptions about future through the ADE, changes in winter climate, populations, and future agriculture and forestry including increasing temperatures and changes policies that would either limit or encourage in precipitation could mean incrementally larger irrigation of these sectors. While this is a report water use during the winter. about the impacts and vulnerability for the Winter is historically a time when the region has water sector with respect to climate change, a respite from the intense summer heat, water supply is uninfluenced by climate (given limited use drops, and crop irrigation and production recharge and even more restricted rainfall) so is most substantial. Because the bulk of these primary adaptation strategies fall to demand- demands are consumptive and driven by side management.
79 2. Current water stress and planned responses
Natural sources of freshwater are insufficient Technology transfer between applied research to meet demand. The main reasons for the and practice is a major impediment to water shortage problem in the Abu Dhabi sustainable resource management. The gap Emirate are related to rapid increases in water between the scientific advancements related to demands across various sectors, depletion of water conservation techniques and application groundwater resources, low annual rates of of the technology is still huge; the slow transfer precipitation and groundwater recharge, and of technologies due to both poor coordination so far, an absence of integrated water resource and poor networking among stakeholders. management strategy. Abu Dhabi supplements Leakage from distribution networks has never its remaining freshwater reserves with its large been properly assessed -low water use efficiency desalination capacity, most of these plants run and high water losses in the water distribution in tandem with the power stations. system continue to thwart any efforts to mitigate increasing consumption. The lack of The little rainfall that does occur falls in winter, maintenance and rehabilitation programs to and provides up to 80% of the Emirate’s annual improve and maintain system performance at precipitation. These short, heavy rainfalls the highest possible level has contributed to produce the best opportunities for aquifer the severity of this problem. recharge. Runoff occurs in the non-vegetated Oman Mountains and collects in wadis which The UAE faces difficulties in changing the drain into the U.A.E, eventually recharging unfavorable social habits and attitudes towards the shallow alluvial gravel aquifers. Rainfall water uses and conservation. This is mainly available for runoff and aquifer recharge varies due to poor public awareness programs in the widely in both time, space, and geographically Emirate. The education curriculum at primary though overall amounts are small in this arid and elementary schools does not address water environment (Brook et al., 2005). Summer conservation in an effective manner. rains can occur from Indian monsoons over the Arabian Sea, rare cases of the Inter Tropical 2.1. Regional Supplies: West Convergence Zone shifting northward over UAE (including Liwa) and East and causing overcast weather and thunderstorm activity. (Abu Dhabi City and Al Ain Oasis) The booming economy and industrial development in Abu Dhabi Emirate have The Western and Eastern/Central regions of the increased water demands in the various water Emirate face vastly different supply constraints. consumption sectors. Notably, the per capita Groundwater occurs in the Emirate as either share of freshwater consumption has tripled consolidated or unconsolidated surficial deposit during the last three decades. The average annual aquifers or as bedrock / structural aquifers and precipitation over UAE and the Abu Dhabi contributes 79% to the total water demand. Emirate has reached its lowest levels during the The other water source contributions are from last decade with severe implications for natural desalination and treated wastewater (see Figure recharge of groundwater systems. Groundwater 2‑2 for a breakdown). quality and quantity have deteriorated due to the excessive pumping mainly for agriculture There are six main desalination plants that meet purposes along with the extensive use of Abu Dhabi’s needs. The Emirate uses several chemicals and fertilizers in agriculture. A different methods are available to desalinate detailed discussion of groundwater quality is seawater; the three commercially proven outside the scope of this report. processes being distillation, reverse osmosis
80 Climate Change Impacts, Vulnerability & Adaptation and electro dialysis. Today, the evaporation technique is dominant in the desalination field, where 96% of desalinated water is produced by Multi Stage Flash (MSF) and Multi Effect Distillation (MED). The remaining 4% is produced by reverse osmosis. To improve the desalination process economics, the MSF process is usually coupled with electric power generation in the so called cogeneration plants. in Abu Dhabi & Adaptation for & Of the six main plants, five are situated along the Arabian Gulf coastline at Shuweihat, Mirfa, Abu Dhabi, Um al Naar and Taweelah and the can be found on the Gulf of Oman at Qidfa, Fujairah. The Qidfa, Fujairah plant began production in 2003 and is the first inter-emirate Figure 2‑1. Percentage of total supply. transfer of water from Fujairah to Abu Dhabi. Impacts, Vulnerability Water Resources Table 2‑1. Abu Dhabi Emirate groundwater reserves estimate from GWAP (GTZ, 2005a).
Volume of Drainable Groundwater (km3) Total Fresh Brackish Saline Upper Aquifer (West) 221 12.5 70 138.5 Shallow Aquifer (East) 58 4 10.25 43.8 Western Aquitard (WA) 326.7 0 9.9 316.8 Eastern Aquitard (UF) 35.2 0 25.7 9.5
Sum (km3) 640.9 16.5 115.8 508.6 Percentage of Total GW: 100.0% 2.6% 18.1% 79.4%
Sum West (km3) 547.7 12.5 79.9 455.3 Percent West 85.5% 75.8% 69.0% 89.5% Sum East (km3) 93.2 4.0 35.9 53.3 Percent East 14.5% 24.2% 31.0% 10.5%
Table 2‑2. Western Region Potable Water Consumption from Mirfa and Sila Desalination Plants.(2003)
Weekly Consumption Weekly Consumption Annual Consumption Center % of total gallons Cubic meters Cubic meters Ghayathi 7727620 35130 1826748 6% Delma 9917000 45083 2344299 8% Mirfa 4786470 21759 1131483 4% Liwa 46147640 209787 10908933 37% Madinat Zayed 32675000 148541 7724109 26% Habshan 9629000 43773 2276219 8% Asab 2500000 11365 590980 2% Sila 10536300 47898 2490697 9% TOTALS 123919030 563336 29293467 *Based on weekly consumption for last week April, 2003
81 2‑2. Regional divisions used with indications of irrigated areas, and Eastern domestic well fields. 2‑2. Regional divisions used with indications of irrigated areas, Figure Figure
82 Climate Change Impacts, Vulnerability & Adaptation Total installed capacity equals 648 million region as well, are now met by desalinated gallons per day (MGD) and 16.45 MGD in remote water. Groundwater levels in Al Ain are actually plants, for a combined capacity of 746 Mm³/yr, increasing due to the artificial recharge of 35% of which is currently unutilized (ADEA, groundwater from treated sewage effluent 2002). Al Ain City relies on this inter-emirate (TSE) and desalinated irrigation water widely transfer because much of its desalinated water used to keep the garden city of Al Ain green is imported from the Qidfa plant for domestic, (Brooks et al., 2005). agriculture and forestry usage (Brooks et al., Treated wastewater (effluent) [TSE] is a non- 2005). Western domestic demands are entirely in Abu Dhabi
conventional or non-traditional water source Adaptation for & met with desalination. growing in importance in the Emirate. As By 2003, 1.2 million people produced 140.8 Mm³ urban populations and industrial consumption of treated wastewater from 23 operating plants, expands, so do the waste volumes and the equaling 4% of the total water consumed amount available for re-use. Abu Dhabi has one that year. Utilization of the treated effluent is of the best records for collecting, treating and largely used for irrigation of parks, gardens re-using wastewater and all wastewater which and recreation facilities, and to a much smaller is produced in Abu Dhabi City and its environs degree, irrigation of fodder crops. Notably, the is collected, treated and re-used (Brooks et Impacts, Vulnerability main Al Ain city plant and the Mafraq plant, al., 2005). The use of TSE in irrigation could Water Resources with an installed capacity of 260,000 m³/d (or have positive effect on groundwater recharge, equivalent of ~725,000 persons), treat 65 % of particularly in areas suffering from overdraft. the total population’s wastewater. The Western Region population is sparse with Previously, all of Al Ain city’s domestic water 116,177 in 2001, just 10% of the entire Abu requirements were met from these domestic Dhabi Emirate population. The major mainland wellfields, however, massive increases in settlements are Ruwais, Madinat Zayed, Al domestic demands have placed increasing stress Mirfa, Ghayathi and Liwa and the main Island and resulted in declining water levels, increasing settlements are Dalma, Das and Zakum. Island in groundwater salinity, and decreasing in total populations include permanent settlements production (Brooks et al., 2005). In 2003, the associated with offshore oil & gas installations total domestic eastern well-field production is e.g. oil rigs etc. Municipal consumption is met only 26 Mm³/yr, meeting only 17% of the total from groundwater abstraction, from treated domestic requirements in the eastern region. sewage effluent (TSE) and from desalination. The balance of domestic demand in the eastern This discussion is continued in relation to the region and the full requirements for the western water balance model.
Groundwater Level Change at Hili, Al Ain 3000BC to present Groundwater decline (m)
Years before present
Figure 2‑3. Changes in groundwater levels at Al Ain over the last 4,500 years.
83 The only fresh groundwater in the Western area mainly residential, commercial establishments, is fossilized water immediately north of the Liwa hospitals, hotels, offices, and shops. In Oasis (USGS/NDC, 1994). This basin occupies government sponsored housing development an area of 2,400 Km² with an average thickness schemes and agricultural activities there has of about 30m, although the unconfined “Liwa been a significant increase in customer demand Aquifer” has a maximum thickness of 120m. for water and even more so in the farming and Brackish to saline groundwater is used in the forestry sectors. Municipal water demand in Madinat Zayed, Ghayahthi and Al Wathbah Abu Dhabi Emirate is expected to increase regions and very saline water is also used in from 208 million gallons per day (gpd) in 2000, to the Al Wathbah region. In the Western region, 700 million gpd in 2010, and then to 800 million farmers must use groundwater with salinities gpd in 2015. In 1997, per capita consumption of mostly over 10,000 mg/l and up to 40,000 was around 130 (gcd). Only five years later, mg/l mixed with fresh groundwater imported consumption had grown to 199 (gcd). from Kashona well field in the eastern region and more recently, with desalinated water from Taweelah Citation: (Brook and Hovgani, 2003). Brackish groundwater must be pumped at a considerable distance from the wellfields in the central part of the Western Region to irrigate the trees along the Abu Dhabi – Al Sila highway. All public water supply is provided from desalinated water produced by plants at Mirfa (22.3 Mm³/yr) and Sila (2.4 Mm³/yr). In 2004, a new 166 Mm³/yr desalination plant was commissioned in Shuweihat. An approximate estimate of the relative contribution from these sources is summarized in Figure 2 ‑6.
2-2 Demand Projections
Even though domestic consumption is only roughly 15% of total water consumed in the Emirate, there are numerous issues that threaten to increase municipal consumption. Figure 2-4.Summary of total sector consumption Domestic consumption in the UAE includes by region (2002).
Table 2-3. Total water consumption in Abu Dhabi for the year 2003
EAST WEST % TOTAL (ERWDA, 2002 Efficiency of Irrigation (Mm3) % (Mm3) % (Mm3) %
Domestic 107.81 7.07 332.8 19.6 440.6 13.7
Industry 11.9 0.78 36.9 2.2 48.8 1.5
Agriculture 1191 78.06 772.9 45.6 1963.9 61.0 90%
Forestry 105 6.88 407 24.0 512.0 15.9 90%
Amenity 110 7.21 145.98 8.6 256.0 7.9 80-90%
TOTAL 1525.7 100.0 1695.58 100 3221.3 100.0
84 Climate Change Impacts, Vulnerability & Adaptation Without demand management strategies off-shore facilities meet their own water demand implemented, per capita consumption is with independent desalination plants. In the likely to continue to increase at 6% annually. western region, industrial demand is restricted Additionally, total population is growing. In 2007, mostly to 18 group companies. Ruwais, for the population of the Abu Dhabi metropolitan example is an on-shore facility with the largest area was 930,000 people. Researchers estimate demand, although it is both an industrial and that by 2013, metro area population will grow residential zone. There are 1300 units and to 1.3 million, and then 2.0 million by 2020 and houses which are home to about 20% of the total 3.1 million by 2030. As water is scarce for a population in the western region. The housing in Abu Dhabi present total Emirate population of 1.5 million complex consumes 1.4 Million m³/yr of water: 57 Adaptation for & (ADEA, 2002), it is unlikely that the region % from treated Effluent and 43 % potable. will have enough water to support per capita consumption of 220+ gallons per day for 3.1 2.3. Irrigation Strategies million people. Overall, agriculture, forestry and amenity As economic development and improved watering make up roughly 82% of Abu Dhabi’s standards of living continue to be a national total water consumption, and most if not all of trend, Emiratis have become larger water this demand is met through various irrigation Impacts, Vulnerability consumers. In fact this trend may prove Water Resources strategies. (Mac Donald, 2004). Between 1979 independent of economic growth as Figure and 1985, agricultural production increased 2‑9 shows where despite lower GDP between nationally six-fold; between 1995 and 2006, 1983-1990 due to lower oil prices (main revenue agriculture in the Abu Dhabi Emirate practically driver) per capita consumption contined to doubled but has since level off, likely due to grow. water scarcity. At the same time, agriculture The Industrial sector currently only accounts contributes less than 2 percent of the UAE’s for 1.5% of total Emirate water consumption (in GDP (Federal Research Division). Agriculture 2003). This proportion will increase as expansion is generally dominated by two perennial crops, in the sector grows with the development of a dates and Rhodes grass, with some seasonal number of new industrial estates in Abu Dhabi, plantings of short season annual vegetable Al Ain and elsewhere. For the time being, most crops; a limited area of cereals and fruits are
Figure 2-5. GDP and bulk per capita water use in Abu Dhabi.
85 also grown. Most agriculture is on small private range of crops. At the former site, desalinated farms that have been established in relatively water, imported from the Qidfa, Fujairah plant, recent times, but there are also small areas is blended with indigenous, brackish water to of traditional date palm gardens and larger produce an irrigation water quality of about government forage production units. Since 1000 mg/l TDS, once again allowing for growing the 1970s, there has been a drive to increase of fruits and vegetables. agricultural production that has led to a rapid Users employ traditional water utilization and depletion of underground aquifers, lowered conservation along with new management water tables, and caused extreme increases in methods. Water conservation and new soil and water salinity. technologies to sustain supply in the semi- A considerable amount of investment has been arid climate include desalination plants, made to ‘green’ the desert. In 1974, there was construction of dams, restoration of traditional only one public park in Abu Dhabi with very little underground water channels (falaj system), well greenery, but today the number has increased drilling and aquifer testing and exploration. For to about 40, covering an area of more than 300 the last 3,000 years or so aflaj have provided for hectares. The expansion of the green areas in sutstainable agriculture and civilisation in the the Emirates is in line with the department’s Al Ain Region. While historically reliant on the goal of extending the greenery to cover 8 per aflaj, water users in the Al Ain region have seen cent of Dubai’s total urban area. During 2003, their usability decrease to declining groundwater another 30 ha were added to Dubai’s greenbelt. levels in the source or mother well areas over At present, the planted area amounts to the last 20-25 years. Despite the difficulties in about 3.2 % or 2200 ha (Ma, 2005). Amenity maintaining the aflaj flows, it is the strategy plantations use an estimated 245 Mm³/yr of of Al Ain Municipality who supports the falaj water from a combination of treated effluent, systems, as per decree by the late Sheihk Zayed desalinated water and also local groundwater. bin Sultan Al Nayhan, will continue to finance In Al Ain, traditional oasis plantations that the Falaj and the area of oases that they sustain relied previously on aflaj irrigation have since at all cost. At the same time, the water table in become supported by wells when the aflaj flows the vicinity of the aflaj shari’a itself has steadily ceased in the early 1990’s. risen in recent years due to artificial recharge of groundwater from treated sewage effluent The lack of arable land, intense heat, periodic and desalinated irrigation water which is now locust invasions, and limited water are major widely used to keep the garden city of Al Ain obstacles for the agriculture sector. Lack green (Brook et al., 2005). of precipitation means that agriculture is Localized irrigation strategies are dominated dependent on irrigation, which is sourced by drip, trickle, and bubbler methods but some from groundwater (both fresh and desalinated overhead irrigation is used on lawns and some brackish and saline), treated sewage effluent forage. Most forage is grown with drip irrigation. (TSE), and desalinated water. The main A small amount of flood irrigation (basin) is still problem is that groundwater systems can undertaken in traditional date garden areas. no longer adequately support existing, large For several reasons (rising average salinity of agricultural developments. Alternative water groundwater, difficulties in maintaining yields of sources are now being investigated and utilized. irrigation water from boreholes, a dramatically Much of the farm and forest sector use brackish increasing irrigated farm area), drip irrigation groundwater while amenity plantings rely on has become almost the sole irrigation method, both TSE and wells, especially in Al Ain city a situation which is probably unique in the where over 400 have recently been inventoried. world. Treated effluent is also used for irrigation of small scale fodder farms. Amenity watering For a while, subsidies promoted agricultural relies predominantly on TSE. For example, at expansion to the tune of 3,000 new farms (of 2-3 the Nakheel and Al Ajban farms, desalinated ha) each year, although expansion is currently water is now being utilized for irrigation, restricted due to exhaustion of groundwater allowing for a much wider and marketable supplies and has leveled off somewhat. We
86 Climate Change Impacts, Vulnerability & Adaptation in Abu Dhabi & Adaptation for & Impacts, Vulnerability Water Resources
Figure 2‑6. Expansion and plateau of Abu Dhabi Citizens Farms, 1996-2005 expect this trend to continue, if not lead towards to supply 52,775 ha of forest. It is notable that a decline of farmed hectares as water becomes some natural forests of Ghaff, Samar and Arta scarcer and more expensive (if agriculture survive without irrigation. Where water supply increases reliance on desalinated sources). is not constrained, daily irrigation schedule is based upon 8 hr/day groundwater well pumping; All forestry is irrigated by groundwater; this is said to give between 1220 and 2220 gal/ha/ however recently, there is a development to day (equivalent to 0.55 and 0.99 mm/ha/day. supply limited desalinated water to some projects in the western region. The forestry On forest sites where water is scarcer, irrigation sector is faced with operational challenges is restricted to alternate days. In general, trees related to poor water quality, lack of sufficient are under- irrigated because of water shortage quantity of irrigated water and also poor (i.e. irrigation is related largely to water supply) quality soils. Fortunately, this has led to an and acknowledge that the irrigation is not emphasis on planting indigenous species really monitored in any way. In the Abu Dhabi allowing the use of brackish and saline waters Municipality, irrigation for amenity watering through drip irrigation in an extreme arid zone is not monitored but there has been a rough environment. The Al Ain Forestry Department target of 5-8 gallons/tree/day, while 4 gallons/ estimates water use, which vary according to day is more likely due to acute shortages of site, at between 6.1 and 11.1 gallons/tree/day. water. For a description of hectares under The Forestry Department also estimate that irrigation in different regions used in our model 58,319,700 gal/day are pumped from 2,663 wells see Annex 1.
87 3. Qualitative climate impact assessment of water resources
The hyper-arid climate of the UAE suggests variability that the primary driver of water supply changes 3.6 - Rainfall variability and flash flooding will be demand and the subsequent rate of 3.7 - “Greening the desert”: a vision at risk groundwater abstraction. As the situation stands today, precipitation and recharge are not 3.8 - Vulnerability of Irrigated Agriculture major contributors to the Emirate’s freshwater 3.8.1 - Groundwater over pumping resources. The water supply is dominated by 3.8.2 - Salt buildup the abstraction of fossil groundwater or ground We conclude with a discussion of the uncertainty water that has been in underground aquifers of climate change-related impacts, and a for millennia. The intense rate of development challenge to water planners. expansion, combined with additional pressures from population growth and per capita consumption in the Emirates has called upon 3.1. Global Climate Change this non-renewable water resource. The scientific evidence for human-caused global An increase in municipal and industrial water climate change has become quite compelling in demand, due to climate change, is likely to be recent years. The Intergovernmental Panel on rather small, e.g., less than 5% by the 2050s in Climatic Change (IPCC) recently released the selected locations (Mote et al., 1999; Downing first of four parts of its Fourth Assessment Report et al., 2003). An indirect, but small, secondary (AR4 IPCC 2007), describing the science and effect would be increased electricity demand physical evidence surrounding climate change. for the cooling of buildings, which would tend The consensus among involved scientists and to increase water withdrawals for the cooling policy makers is that “[… global atmospheric of thermal power plants. For example, all of concentrations of carbon dioxide, methane Al Ain city’s domestic water requirements and nitrous oxide have increased markedly as were once met from wellfields. More recently, a result of human activities since 1750 …] and massive increases in domestic demands, from the understanding of anthropogenic warming an annual population growth rate of 8 %, has and cooling influences on climate leads to very meant that wellfields have been placed under high confidence that the globally averaged net increasing stress, resulting in declining water effect of human activities since 1750 has been levels, increase in groundwater salinity with one of warming“ (IPCC, 2007). Certainly, other a resultant decrease in total production. forcings act on the climate system beyond Population growth and per capita increase human influences, most notably solar, volcanic, changes in water demand are likely to be the oceanic, and cryogenic (ice), but when these primary drivers of water scarcity in the UAE; processes are included alongside human forcing, however, the following sections will pull from an anthropogenic “fingerprint” emerges. the international literature in order to raise CO2 is a major green house gas, contributing awareness to what can be understood as somewhere between 10 and 25 percent of the potential climate change impacts on water natural warming effect, second only to water resources. These sections include: vapor. As the earth emits long wave radiation 3.1 Global Climate Change toward space, atmospheric constituents like 3.2 Regional Climate Change water vapor, CO2, ozone, and methane absorb 3.3 GCM Scenarios for the UAE this energy flow and radiate energy back to earth. Climate models suggest that without 3.4 Temperature Increase and diminished surface water reserves these greenhouse gases the average earth temperature would be about -19ºC, and in the 3.5 Increased monthly precipitation absence of other changes and feedbacks in the
88 Climate Change Impacts, Vulnerability & Adaptation in Abu Dhabi & Adaptation for &
Figure 3-1 Global average temperature and CO2 trends (Karl and Trenberth 2003). Impacts, Vulnerability Water Resources climate system, a doubling of CO2 would warm considered, there is a net positive radiative the lower atmosphere by about 1.2ºC (Kiehl forcing on the order of 1.5 watts per square and Trenberth, 1997). meter (W/m2). In Figure 3-2, “positive” means that the earth is gaining energy faster than it is Figure 3‑1 is a plot of annual mean departures losing it (RF-Radiative Forcing; LOSU- Level of from the 1961-90 average for global temperatures, Scientific Understanding) with an underlying mean of 14.0°C, and carbon dioxide concentrations from ice cores and Problematically, CO2 has a relatively long Mauna Loa (1958 on), with a mean of 333.7 ppmv residence time in the atmosphere and while (updated from Karl and Trenberth 2003). The its sources are local, it is generally globally plots show that the rise in CO2 coincides with a distributed. Recognizing that it is a strong rise in global average surface temperatures. forcing component, the IPCC has convened panels of experts that have developed Increasing CO2 is not the only human activity “storylines of the future”, which are used to affecting our climate system and in fact, CO2 project concentrations of greenhouse gases. is only responsible for about two-thirds of the These transient concentrations are then used greenhouse effect, the reset being methane, in Global Climate Models (GCMs) to project nitrous oxide, chlorofluorocarbons, and ozone. the relative contribution of CO2 (and other Changes in land use, aerosol emissions from factors) to future warming. Most GCMs consist fossil fuel burning, the storage and use of of an atmospheric module that is coupled to the water for agriculture, etc. are all environmental other key components of the climate system, changes that affect climate (Pielke et al., 2007). including representation of oceans, sea ice, and Climatologists have tried to quantify the relative the land surface. The major GCMs include tens role of various human factors on the climate of vertical layers in the atmosphere and the system in terms of each component’s “radiative oceans, dynamic sea-ice sub-models and effects forcing”, which are summarized from the IPCC of changes in vegetation and other land surface Fourth Assessment Report (IPCC, 2007). Most characteristics (Washington, 1996; Gates et notably, the radiative forcing of CO2 is the largest al., 1999). The atmospheric part of a climate single component, with natural solar irradiance model is a mathematical representation of the (solar variability) substantially smaller. Also, behavior of the atmosphere based upon the there are human activities that counteract the fundamental, non-linear equations of classical positive forcing of CO2. For examples, aerosols physics. A three-dimensional horizontal and from the burning of fossil fuels tend to reflect vertical grid structure is used to track the heat back into space, reducing the net heat movement of air parcels and the exchange of at the surface. When all the components are energy and moisture between parcels.
89 Radiative Forcing Components
RF Terms RF values (W m-2) Spatial scale LOSU
CO2 1.66[1.49 to 1.83] Global High Long-lived N2O greenhouse gases 0.48 [0.43 to 0.53] 0.16 [0.14 to 0.18] Global High Halocarbons CH4 0.34 [0.31 to 0.37]
0.05 [0.25 to 0.65] Continental Ozone Stratospheric Tropospheric Med 0.35 [0.25 to 0.65] to global
Stratospheric water 0.07 [0.02 to 0.12] Global Low vapour from CH4
Land use -0.2 [-0.4 to 0.0] Local to Med Surface albedo Black carbon 0.1 [0.0 to 0.2] continental -Lowl onsnow Anthropogenic Direct e ect -0.5 [-0.9 to -0.1] Continental Med to global -Low Total Aerosol Cloud albedo -0.7 [-0.8 to 0.3] -Continental Low e ect to global
Linear contrails 0.01 [0.003 to 0.03] Continental Low l ra Solar irradiance 0.12 [0.06 to 0.30] Global Low Natu
Total net 1.6 [0.6 to 2.4] anthropogenic
-2 -1 012 Radiative Forcing (W m-2)
Figure 3‑2 Relative radiative forcing attributable to human activities. (IPCC, 2007)
Figure 3‑3. Historic observed global average temperatures, and projected global average temperatures based on various projections of global CO2 concentrations. (IPCC, 2007)
90 Climate Change Impacts, Vulnerability & Adaptation The CO2 storylines include both “green” critically important in determining changes in centered trajectories that moderate fossil precipitation, and climate models can provide fuel use and fossil fuel intensive trajectories, only a crude picture of how those patterns leading to either low or high green house gas may change. The currently available evidence concentrations, respectively. These different suggests that arctic and equatorial regions emission pathways then imply different mean may become wetter, and that subtropical global and regional climate warming rates. regions may experience drying. Projections of The details of these Scenarios are beyond the precipitation changes for mid-latitude regions scope of this report, but Figure 3‑3 summarizes such as the ADE are less consistent. in Abu Dhabi the projected global average surface warming Adaptation for & In some places, there is stronger consensus based on a consensus derived from several among different climate models that gives rise GCMs across a range of future projections to stronger ‘confidence’ in regional precipitation (e.g. referred to ‘A2’, ‘A1B’, and ‘B1’ Scenarios, for details about the different Scenarios, see changes. For example, a recent report by Seager http://www.ipcc.ch/pub/sres-e.pdf). Note this (2007) argues for an imminent transition to a figure includes a projected global average drier climate in southwestern North America. He points out the consistency of climate models temperature if we were to keep CO2 at 2000 concentration levels, suggesting that we are in producing a human-induced aridification Impacts, Vulnerability already committed to some additional warming caused by large scale changes in the atmospheric Water Resources beyond anything that has taken place already branch of the hydrological cycle, stating that (IPCC 2007). “the subtropics are already dry because the mean flow of the atmosphere moves moisture The consequences of the projected future out of these regions whereas the deep tropics warming are likely to be changes in and the higher latitudes are wet because the atmospheric and oceanic circulation, and in the atmosphere converges moisture into those hydrologic cycle, leading to altered patterns regions. As air warms it can hold more moisture of precipitation, groundwater recharge, and and this existing pattern of the divergence and surface runoff. Warmer temperatures and even convergence of water vapor by the atmospheric changes in other climate variables like wind flow intensifies. This makes dry areas drier and and humidity, could lead to change in water wet areas wetter.” demands for outdoor irrigation needs. Warmer temperatures, accompanied by increases in Figure 3‑4 shows projected patterns of wind and lower humidity in the interior could precipitation change. Note the general pattern lead to higher demands in the agricultural of drier conditions in the mid-latitudes and sector. Scientists agree on some of the important desert regions, and wetting in the tropics broad-scale features of the expected hydrologic and high latitudes (IPCC 2007). The dark changes, the most likely of which will be an stipples in this figure are places where there is increase in global average precipitation and consensus among models with regards to the evaporation as a direct consequence of warmer direction of future climate change. So in the temperatures. That, however, does not mean poles and some tropical regions, there is more that there will be more precipitation everywhere stippling, suggesting more model agreement, or that groundwater recharge would increase in suggesting the greater likelihood that the poles proportion to precipitation, as other factors like will get wetter and the mid-latitudes drier. changes in evaporation could overwhelm any Problematically for the ADE, Figure 3‑4 shows increased precipitation. in white no stippling, suggesting no strong trend in precipitation (either wetter or driver) 3.2. Regional Climate Change and thus little agreement among models. Thus, for the water resources sector of the ADE, At the regional scale, such as the ADE, there a conservative assumption regarding future is high confidence in projections of future precipitation is that the near future will be like temperature change, with less confidence in the recent past- very arid. projections of future precipitation change (Dai, 2006). Changes in circulation patterns will be Despite tremendous technological advances
91 Proejected Changes in precipitation from 1980-99 to 2090-99
December- February
Percent Change
+20
+10
+5
-5
June- -10 August -20
unclear Change
Figure 3‑4. Statistical summary of projected patterns of precipitation change from multiple General Circulation Models for December, January and February (left) and June, July, and August (right).
in computing capability, it is still very time rises over mountains or hills, the moisture consuming and costly to use these models condenses, producing clouds and, if conditions to simulate future climates. One of the most are right, precipitation. Although there has important compromises for achieving model been marked improvement over the last three results in a reasonable amount of time is to decades in the simulation of precipitation, it is decrease the model’s horizontal resolution. still not well represented in GCMs, especially This limitation means that it is prohibitively in areas of complex topographies, since the costly to run a GCM at a spatial resolution that coarse horizontal resolution of GCMs tends would accurately depict the effects of mountains to smooth out important landscape features and other complex surface features on regional that affect atmospheric processes. At the climates. resolution of most GCMs the models do not The problem with such a coarse horizontal adequately represent the Oman Mountains and resolution is that important processes occurring if they do, they are simply gentle ridges and do at finer scales are not well defined. Topography, not resolve finer scale features that influence for example, is very important in determining regional climate. Clearly, that level of spatial the location of precipitation. As moist air resolution is too coarse to reproduce the effects
92 Climate Change Impacts, Vulnerability & Adaptation of topography on the region’s precipitation and the middle of the 21st century. Section 3.3 goes groundwater recharge patterns (Grotch and into greater detail on the seasonal distribution MacCracken, 1991; Giorgi and Mearns, 1991; of change and the generation of specific climate Pan et al., 2004). Scenarios for this analysis.
The current inadequacies of GCMs and the In Figure 3-5, the SRES Scenarios B1 (Figure recognition that each has its own strengths and 3-5a and 3-5c) and A1B (Figure 3-5b and 3-5d), weaknesses has led researchers to conclude and annual average change in temperature and that no single model can be considered ‘best’ change in precipitation in mm/day. The colored and it is important to utilize results from a makers and labels are the individual models that in Abu Dhabi & Adaptation for & range of coupled models for regional impact contribute the creation of the distribution. and adaptation studies (Allen et al., 2000). Tebaldi et al., (2005) presented a probabilistic 3.3. Generating Climate Scenarios approach that combines the regional output for the ADE of 21 unique GCMs to produce probabilistic projections of regional, future climate change. Given the ambiguity of future change in Their statistical model combines information precipitation and the strong consensus of from each GCM, including each model’s ability changes in temperature on the order of 1ºC to the Impacts, Vulnerability to re-create the regional climate over the period middle of the 21st century, we developed relative Water Resources 1960 through 1990 (a measure of a model’s bias), “simple” climate change Scenarios that reflect and the agreement among models in future these general observation of projected climate projections. Models that diverge greatly from change from a host of GCMs. Results from other models are given less weight in deriving downscaled General Circulation Models (GCM) the final statistical distributions of change. provide the maximum and minimum projected change in temperature and precipitation for Figure 3‑5 shows probabilistic projections of Abu Dhabi city in 2050 and 2100. For each of four future seasonal temperature and precipitation climate change Scenarios (A1, A2, B1, and B2), change for the region of the United Arab the projected maximum/minimum changes are Emirates for the decade around 2050 for the calculated based on 5 GCM outputs (CCC196, low CO2 emission, B1 scenario; and the high CSI296, ECH496, GFDL90, and HAD2TR95). A1 emissions scenario. The projected mean Table 3‑1 presents absolute values (e.g., annual differences among the two Scenarios at 2050 for average temperature in Abu Dhabi in 2050) temperature are about 0.5°C. The B1 projection and projected changes in absolute values (e.g., of the change in annual average temperature is incremental rainfall relative to the 1961-90 about 1.5°C, while the A1B projected change in at 2050 is about 2.0°C It isn’t until later in the annual average). 21st century, that the projections diverge under Two summary Scenarios can be derived from the various CO2 Scenarios. these projections: 1) a best case scenario in The Tebaldi et al., (2006) results suggest a GCM which precipitation actually increases 10.33% model consensus of temperature increases a bit compared to the 1961-90 baseline and average below 1°C over the next 20 years (not shown), air temperatures warm +1.74°C by 2050; and 2) with some seasonal variation. For precipitation, a worst case scenario in which temperatures the B1 Scenarios seems to suggest a slight warm 2.67°C and precipitation decreases 21.20% “probability” of a decrease in precipitation given as an annual average in units of mm/day. There Table 3‑1. Summary of GCM Outputs is substantial spread across the distribution for Abu Dhabi in terms of both increases and decreases in annual precipitation, with the A1B scenario Temperature Precipitation showing the same kind of spread, although its -21.20% to +10.33% +1.74 to 2.67°C (2050) mean value seems to be right at the 0 mm/day (2050) relative change, suggesting equal likelihood of -37.82% to +18.42% +3.11 to 4.76 ° C (2100) either increase or decreases in precipitation by (2100).
93 Figure 3‑5a. Probability Density Function -b1_temp_2050_annual
Figure 3‑5b. Probability Density Function -a1b_temp_2050_annual
94 Climate Change Impacts, Vulnerability & Adaptation in Abu Dhabi & Adaptation for & Impacts, Vulnerability Water Resources
Figure 3‑5c. Probability Density Function - b1_precip_2050_annual
Figure 3‑5d. Probability Density Function - a1b_precip_2050_annual
95 Similarly, for 2100, increases in average monthly temperature could range from about 3.3ºC in February to about 4.5ºC in October (again, relative to the corresponding monthly average over the 1961-90 baseline periods).
Temperature strongly influences the amount of evaporation in an area. In hot, dry climate evaporation of irrigation water is a serious problem whether from the soil, plant leaves Rainfall Change (%) or other wet surfaces. Improving irrigation efficiency allows farmers to avoid severe water Temperature Change (degrees C) Temperature loss. The key is custom-designed strategies to get more output and benefit from water by creating a best-fit technology linked to local climate, Figure 3-6. Maximum and minimum projected hydrology, water use patterns, environmental temperature and rainfall change. (UAE, 2006) conditions, and other relevant characteristics.
3.5. Increased monthly by 2050. precipitation variability GCM outputs illustrated in Figure 3-6 show that temperatures are projected to be between about Rainfall within Abu Dhabi Emirate is erratic 1.6ºC and 2.9ºC warmer in 2050 than they were both in time and space. Rainfall provides water over the period 1961-90, and between 2.3ºC and for runoff, which eventually results in aquifer 5.9ºC warmer than this baseline period by 2100. recharge, especially in the eastern regions where numerous wadi systems cross over the border The precipitation projections, however, are more from Oman to provide preferential pathways for varied. Some models project a dryer region with percolation and recharge. This recharge water decreasing precipitation, while others project is important, however, it only contributes, on a wetter region with a significant increase in average, 4 % annually to the Emirate’s total water precipitation. Figure 3‑8 in Section 3.5 conveys consumption. Even so, changes in precipitation the projection of rainfall in 2050 to be between patterns threaten to eliminate even that small 20% less to 10% more than has occurred over contribution to Emirate water supply. the period 1961-90, and between 45% less to 22% more by 2100. Additionally, the IPCC notes an Precipitation projections show even greater increasing trend in the extreme events observed variation than temperature. Some models during the last 50 years, particularly heavy project a dryer region with decreasing precipitation events, hot days, hot nights and precipitation, while others project a wetter heat waves. Projections indicate this trend will region with a significant increase in precipitation. continue, if not worsen. As illustrated in Figure 3‑8, average monthly rainfall in 2050 is projected to range between 3.4. Temperature Increase and 8% less in April to about 45% more than these diminished surface water corresponding months over the period 1961-90. For 2100, average monthly rainfall changes are Reserves projected to range between 15% less in June to Projected changes in monthly temperature about 88% more in September, relative to the vary widely across the various GCMs, Scenarios 1961-90 baseline period. considered, and cities within the UAE. Average Mean annual rainfall for the western region of monthly temperatures in 2050 will be warmer the Emirate is less than 50 mm/yr and for the than they were for the corresponding months eastern region, varies between 80-100 mm/yr. over the period 1961-90:- from 1.6ºC in January An estimate of 100 mm/yr has been shown to be to about 2.5ºC in September (Figure 3‑8). required in order to activate sufficient runoff to
96 Climate Change Impacts, Vulnerability & Adaptation in Abu Dhabi & Adaptation for & Temperature Change (degrees C) Temperature Temperature Change (degrees C) Temperature Impacts, Vulnerability Water Resources
Figure 3‑7. Projected monthly temperature change, 2050 and 2100. (UAE, 2006) Rainfall Change (%) Rainfall Change (%)
Figure 3‑8. Projected monthly rainfall change, 2050 and 2100. (UAE, 2006) cause aquifer recharge (Dincer, 1974; Faloci & annual average and have a very significant Notarnicola, 1993). impact on restoring groundwater levels (ADEA, 2002). Groundwater systems are controlled by 3.6. Rainfall variability and flash recharge processes, the geology of the host flooding rocks, and residence time of groundwater and discharge processes. The resultant groundwater Some years, there is no rain at all, and in others, quality is largely influenced by groundwater rain occurring on only a few days in the year residence time and type of recharge process, can total more than three times the long term and in more recent times, by anthropogenic
97 Table 3‑2. Shwaib diversion structure.
Project Item Dimensions Capacity Mm3
Shwaib Dam Length 3000 m, height 11m 5
Approach Channel Length 3600 m, width 150 m 5.5
Shwaib Reservoirs Seven reservoirs 21
Total Shwaib Dam and Reservoirs project 31.5
activity and its availability by aquifer type 3.7. "Greening the desert": a vision and surrounding development (ADEA, 2002). at risk Currently, the highest risks of flash flooding occur in wadis Shik, Sidr and Ain Al Faydah UAE President Sheikh Zayed bin Sultan Al and the lowest risk in wadis Khuqayrah and Nahyan dreamed of turning the country green. Muraykhat. The predicted long term annual Over the last few decades, a massive programme average runoff for the former basins is 1.96 Mm³/ of afforestation has led to the planting of over yr and for the latter, 13.78 Mm³/yr. 120 million trees, as well as 25 million date palms. Some of these trees were planted in Droughts, floods, and other events that alter urban centres, where carefully-maintained rainfall may overwhelm even an advanced parks and luxuriant roadside gardens offer society’s ability to cope. Archeological evidence a pleasing quality of life for the people. Most suggests that the abandonment of several of the planting, though, has been conducted cities in the course of history can be linked to in the desert, where huge new forests have water scarcity and changes in water availability. been established. This “greening the desert” Flash flooding and any subsequent inability to initiative has an important cultural value for capture rainfall adequately will lead to extreme Abu Dhabi, and serious consideration will are runoff, nutrient loading, and, depending on needed in determining the costs and benefits proximity to coastlines, sedimentation of of continuing to green the desert, given the coastal ecosystems like sensitive corals. challenges of climate change.
Abu Dhabi has invested in new dams across Climate change has a profound impact on the the Emirate. Designed to divert wadi flow into forestry sector. This includes changing the surface reservoirs, as temperatures rise surface habitat location of forest species, especially water reserves are increasingly at risk. Warmer the less tolerant ones and the extinction of low air, while increasing evaporation of surface tolerant species. The Municipality Agriculture water, also means that the atmosphere holds Department explains that irrigation of forestry more moisture and rainfall patterns will shift. is undertaken mostly, with a small number of Increasing frequency of extreme and/or erratic farms, parks, gardens and road verge projects. rainfall events have led to dam overflow and Based on an 8-hour/day pumping regime, the flash flooding in other countries, and while combined water requirement is about 64Mm³/d. it is unlikely that these kinds of events will The Ministry also notes that trees tend to be occur in the UAE, the possibility still exists, under-irrigated and species are chosen that are putting downstream agriculture at risk of tolerant of the salinity levels of groundwater. flash floods (Postel, 1999). Water quantities that pass through the Shabit structure are 3.8. Vulnerability of irrigated summarized in Table 3-3; the main beneficiary agriculture of the structure’s enhancement of groundwater Ancient civilizations depended on irrigation to recharge is agriculture as numerous farms exist sustain agriculture just as much of the world does immediately south of the diversion structure. now. At least half a dozen major irrigation-based civilizations have been undermined by salt, silt,
98 Climate Change Impacts, Vulnerability & Adaptation neglected infrastructure, regional conflict, and prime example of the tragedy of the commons; unexpected climatic change (Postel, 1999). It is the explosion of private and unmonitored no secret that major empires throughout human wells, tapping into Abu Dhabi’s underground history have collapsed from abrupt climate resources undermines any existing sustainable change, increased salination of the soil, and water resource management strategies. It is far water scarcity. Unless contemporary irrigation more serious when drawing on non-renewable strategies are transformed, societies whose or fossil aquifers, such as those found in arid agricultural productivity is entirely dependent regions like North Africa and the Middle East, on irrigation will be undermined by similar because they have little to no replenishment in Abu Dhabi threats. In particular, as the risks from climate Adaptation for & from scarce rainfall. The issue is that agriculture change to agriculture are unequivocal and in these regions is supported by the equivalent imminent, Abu Dhabi’s reliance on irrigation is a serious consideration when devising an of deficit financing, and countries are racking adaptation plan for the water resources sector. up large water deficits that will likely have to be balanced at some point—whether by artificial Postel (1999), in her book Pillar of Sand: groundwater recharge, or shifted reliance to Can the Irrigation Miracle Last?, warns that 100% desalination. as urbanization leads to higher urban and industrial water demands, it’s likely that these Without changes in water withdrawal and Impacts, Vulnerability demands will be met through a transfer of water irrigation behaviors, further degradation of Water Resources resources from agriculture. In a country whose soil and reduction of available water resources economy is heavily dependent on agriculture, is inevitable (Postel, 1999). Fortunately, the farm-to-city reallocation of water could groundwater consumption has decreased undermine the ability to feed itself and more somewhat. The total water used in 2005 is 8% less broadly, the world’s ability to feed itself. One than that used in 2003. Aquifer depletion under way to mitigate the farm to city transfer, in a general regime of unsustainable development addition to improving irrigation efficiency, is brought about a corresponding 18% reduction the increased use of treated urban waste water in groundwater used (ADEA, 2005). The for irrigation. biggest opportunity for narrowing the supply- Impacts of climate change on irrigation water demand gap lies in slowing population growth, requirements may be large. A few new studies improving efficiency of water use, and shifting have further quantified the impacts of climate it out of agriculture—particularly given climate change on regional and global irrigation change. requirements, irrespective of the positive effects of elevated CO on crop water-use efficiency. 2 3.8.2. Salt buildup Döll (2002), in considering the direct impacts of climate change on crop evaporative demand, Salt can undermine soil productivity when but without any CO2 effects, estimated an too much remains on soil. In hotter and drier increase in net crop irrigation requirements climates, farmers must fight high rates of evapo- (i.e., net of transpiration losses) of between 5% transpiration by applying more water to the and 8% globally by 2070, with larger regional soil. As water evaporates, salt remains on the signals (e.g., +15%) in south-east Asia. (IPCC surface, poisoning crops. Soil salinity is likely 2007; IPCC SR 2008). undermining a good percentage of increased productivity achieved by advances in irrigation. 3.8.1. Groundwater over-pumping Seepage from heavy irrigation areas then raises the salinity of groundwater. Groundwater over-pumping may be the single biggest threat to irrigated agriculture, exceeding To mitigate this effect, drainage systems even the buildup of salts in soil (Postel, 1999). need to be installed at the time of irrigation Countries with large and growing populations infrastructure, rather than after the fact. and large irrigated areas are drawing down Additionally, the hyper-saline drainage water aquifers to meet today’s needs, leaving less for needs to be dealt with. Releasing this water to future needs. Groundwater over-pumping is a the Arabian Sea has potentially grave impacts on
99 near-coastal ecosystems. Reducing drainage is Tropical storms and other hazards are of key; implemented by reducing irrigation volume particular concern if and when the majority of using advanced technologies and eliminating the UAE’s water supply for human consumption system inefficiencies. Drainage water can also and otherwise relies on the country’s capacity to be captured and reused for plants with higher desalinate Persian Gulf seawater. Desalination saline tolerance. plants are easily sabotaged; they can be attacked from the air or by shelling from off- 3.9. Uncertainty of climate impacts: shore; and their intake ports have to be kept a challenge to water planners clear, giving another simple way of preventing their operation (Bullock and Darwish, 1993). There are several potential sources of According to the Central Intelligence Agency’s uncertainty associated with the GCMs used to “Middle East Area Oil and Gas Map” there is provide the results summarized above. These a stunning concentration of oil facilities in the uncertainties include the way that atmospheric region. (Middle East Area Oil and Gas Map, boundary conditions are represented in the Central Intelligence Agency map #801357, June models, the manner in which aerosols and 1990). The Persian Gulf has 29 major tanker drift are addressed, as well as the inherent ports and 16 major shore-based refineries and uncertainty associated with the greenhouse the United Arab Emirates exemplifies this gas emissions Scenarios themselves. While pattern with 10 tanker ports and 3 coastal droughts and changes in precipitation patterns refineries that share approximately 300 miles are typically regarded as inevitable, uncertainty of coastline with 40 major desalination plants surround the degree of severity and the extent (Wangnick, 1990). to which remaining resources are impacts. One team of researchers has already modeled Water use, in particular that for irrigation, gen- the effect of an oil spill near Umm Al Nar erally increases with temperature and decreas- desalination plant. Malek and Mohame (2005) es with precipitation; however, there is no evi- used a hydrodynamic model to predict the dence for a climate-related long-term trend of direction and concentration of oil around the water use in the past. This is due, in part, to the station with emphasis on the places where fact that water use is mainly driven by non-cli- seawater was used as feed water to the station. matic factors, and is also due to the poor quality They discussed the influence of oil contaminated of water-use data in general, and of time-series seawater, when it is used as the feed water to data in particular (IPCC 2007). Stresses on the desalination plant, on the performance of water resources are also evolving simultane- system equipments and production water. The found that contamination of the facilities by oil ously so population pressures on aquifers are negatively affects the efficiency of the seawater now layered with increased temperatures and desalination, the product water itself will be decreasing precipitation. polluted which would cause the complete Among the most important drivers of water stop of the potable water supply and a lower use is population, economic development, and efficiency rate generation of the thermal power changing societal views on the value of water. station. The latter refers to the prioritization of domestic In addition to the uncertainty described above, and industrial water supply over irrigation research of global historical data suggests that water supply and the efficient use of water, heavy rainfall events and prolonged droughts including the extended application of water- should be included in modeling efforts. Studies saving technologies and water pricing (IPCC of coral assemblages in the Arabian Gulf suggest SR on water, June 2008). This is particularly that the area has at least a partial link to the salient when discussing irrigation, because the monsoon and El NiÑo Southern Oscillation rules of irrigation game and working towards (ENSO) events (Purkis and Riegl, 2005). These sustainable management strategies revolves events have increased in magnitude since the around how irrigation is managed and how 1970s and it has been suggested that climate water is allocated (Postel, 1999). change may continue to change the frequency
100 Climate Change Impacts, Vulnerability & Adaptation and magnitude of the ENSO (Haines et al., 2000), the potential to significantly affect the social although the extent of the effect is uncertain. and natural systems of the UAE. Circulation Addressing the uncertainty around the changes in the Arabian Gulf is linked to ENSO events of tropical storms occurrence, on the scale of therefore changes in the cycle of these events 2007’s Cyclone Gonu, is outside the scope of may directly affect the UAE. Risks to the this report, though is an area worth further Emirate’s off-shore, desalination infrastructure research by water planners. While it is difficult whether from oil spills, or cyclones could suggest to model potential changes related to ENSO, a worthwhile investment in a strategic water heavy rainfall, and drought events, they all have reserve safe from these hazards. in Abu Dhabi & Adaptation for & Impacts, Vulnerability Water Resources
101 4. Quantitative climate impact assessment of water resources
Observed water supply and demand data Outdoor water use was treated explicitly to summarized in Sections 2 and 3 were used as account for the climate factors that drive the physical basis to develop a water resource irrigation demand, as higher temperatures, planning model to broadly characterize future lower humidity and high wind speeds increase projections of water use and supply, calibrated irrigation requirements of crops. These with historic data. This model, constructed dynamics are included in order to estimate using the Water Evaluation and Planning future irrigation demand under various climate (WEAP) platform, broadly represents the change Scenarios. A crop water simulator regional supply characteristics described in based on United Nation Food and Agriculture Section 2.1 (e.g. Regional fossil supplies in the (FAO) methods, was used to estimate monthly West, including Liwa), Central (Abu Dhabi irrigation demand for the agricultural, forestry, City), and East (Al Ain Oasis), limited renewable and amenity sectors. The FAO method uses freshwater supplies in the east near Al Ain, and estimates of potential evapotranspiration and both existing and future desalinzation that crop coefficients (Kc) to determine required supply both coastal and inland demands, as irrigation requirements. In addition, we well as municipal waste water reclaimed and used estimates of acreage planted, irrigation used again primarily for amenity (gardens and efficiencies, and leaching requirements to derive parks) uses. The water resource model explicitly estimates of monthly and annual irrigation captures total water demands of the municipal/ demands that would closely match reported industrial (M&I) sectors based on estimates of estimates. population and per capita use, which together comprise domestic indoor uses such as bathing, 4.1. The Water Evaluation and toilet flushing, washing, and water for industrial Planning (WEAP) model of production. Abu Dhabi Emirate This model simulates the observed growth in water demand by the domestic sector, with The Water Evaluation and Planning (WEAP) an increase in consumption of around 15% model was used as the Decision Support System from 2002 to 2003 (e.g. 440 to 522 Million Cubic (DSS) for this study. WEAP is an integrated DSS Meters, and the forestry sector from 510 to 607 platform designed to support water planning Million Cubic Meters), and the small recorded with consideration of both water supplies reductions of 1% and 5% in the agriculture and multiple water demands characterized and amenity sectors, respectively. A smaller by spatially and temporally varying allocation consumption in the agriculture sector is a result priorities and supply preferences. Allocation of a policy to reduce the area under irrigation in priorities identify under conditions of scarce large state fodder farms; the 2002 irrigated area resources, which demands are supplied first of 24,000 ha reduced to 17,000 ha in 2003. This before other competing demands. Supply WEAP model has the capability of including Preferences identify the water source(s) that changes in cropped area and assumptions about supply specific water demands. The WEAP representation of the Abu Dhabi Emirate water irrigation and water use strategies, and thus supplies and demands are presented in the figure the model should be capable of simulating the below, with the inset Figure 4-1 showing the broad, observed water use patterns. Estimates details of the model objects in and around Abu of supplied water use for the years 2002, 2003, Dhabi, and will be used in the discussion below and 2005 were estimated at 3,200 MCM, 3,360 to describe some of WEAP’s functionality. MCM, and 3,111 MCM respectively, and we apply the water resources model to simulate WEAP employs a transparent set of model these uses, driven by both per capita use and objects and procedures that can be used to climate driven irrigation demands. analyze a full range of issues and uncertainties
102 Climate Change Impacts, Vulnerability & Adaptation Table 4‑1. Irrigated Hectares (Ha) from GIS layers.
Region Crop Ha
E Forests (total) 88,749.92
Amenity/Urban greening/ residential properties of palaces Al Ain E 26,074.29 (total) (5814.39ha); Abu Dhabi (20,260ha)
E Farms (total) 89,571.00
W Forests (total) 105,647.5421 in Abu Dhabi & Adaptation for & W Amenity/Urban greening (total) 8580.59
W Hey/Fodder 2185.66
W Farms (total) 36,114.74 Impacts, Vulnerability Water Resources
Figure 4‑1. A WEAP schematic of the Abu Dhabi Emirate.
103 faced by water planners, including those related 4.3. Representing Water Demands to climate, watershed condition, anticipated and Supplies in WEAP demand, ecosystem needs, regulatory climate, operational objectives and available Figure 4-1 shows the representation of Abu infrastructure. The model possesses a graphical Dhabi water supply and demand as depicted in user interface that supports the construction WEAP. The inset box shows some of the detailed of site-specific network representations of objects near and around Abu Dhabi. The watersheds and the water systems contained aggregate municipal and industrial demands within them, and that facilitates multi- for the city of Abu Dhabi are represented by a participant water management dialogues single demand node (inset; red circle). Within organized around scenario development this demand object are fields that represent the and evaluation. WEAP uses a priority-based number of people, their per capita demand, their optimization algorithm as an alternative to monthly use pattern, and their consumption. hierarchical rule-based logic that uses the Transmission losses and consumption are concept of Equity Groups to allocate water in depicted as % values along transmission links times of insufficient supply (Yates et al. 2005 and at the Abu Dhabi demand site. a,b). More information on WEAP can be found at http://weap21.org. The demand priority for Abu Dhabi municipal and industrial demand is given a priority of 4.2. Data requirements and one - it has first priority for water supplies that serve its needs, which are linked to the acquisition demand node by three transmission links Several supporting datasets have been utilized (green arrows) for sources Um Al Naar, Mirfa, in this study, most notably those provided and Taweelah (desalination plants designated by the Abu Dhabi Environment Agency’s with green diamond model objects). Data Water Resources Department in the form input for the desalination sources include their of annual water resource statistical reports installed capacity in millions of gallons per that summarize regional water demands and day (e.g. Taweelah at 228 mgd and Un Al Naar supplies by sector and source. Data from at 160 mgd). In 2003, the total desalinization these reports have been used to represent the production was estimated at about 400 mgd, physical infrastructure such as desalination so these two desalinization objects represent plants, waste water treatment plants, and the bulk of the potable supply. Wastewater is well fields, their capacities; and how they are conveyed from the demand node to the Mafraq connected to various demand sites. These waste water treatment plant with a return flow include estimates available groundwater link (red arrow). The ‘Red-Line’ exiting the storage stratified by fresh, brackish and saline, Abu Dhabi demand node in Figure 4‑1 is the population and per-capita use estimates in both conveyance to the, with the two conveyance the western and eastern regions of the ADE. lines (green lines). Climate data included daily observations of Transmission links from Mafraq represent minimum and maximum air temperature, wind the reuse of treated waste water for non- speed, relative humidity, and precipitation for potable, outdoor irrigation. Irrecoverable Abu Dhabi and Al Ain airport for the period transmission losses in the distribution system 1994 through 2008. from the desalinization water treatment plant Geographical Information System (GIS) are assumed to be 15%, Consumption within datasets were also use to spatially locate the the municipal and industrial demand node supplies and demands throughout Abu Dhabi, is assumed as 10% of what is delivered to the and determine the amount of irrigated acreage node. The model also assumes that 80% of water in each region and by type (agriculture, amenity, that is returned to a waste water treatment forests). The GIS layers include those listed plant can be used for outdoor irrigation (e.g. Annex 1: Data sources and key assumptions, amenity watering). These fractions are shown and the aggregate irrigated area is summarized along the transmission links summarizes the in Table 4-1 drivers of municipal demands for the region
104 Climate Change Impacts, Vulnerability & Adaptation including estimates of population and per- In times of shortage, Abu Dhabi Irg will receive capita demand. water before Al Whathba Forest.
The average per capita domestic demand is Data attributes for the catchment model objects estimated at 525 to 600 l/cap/day, with network include representative area; irrigation timing losses of about 25%. In some areas, where the and efficiency, and climatically driven potential population uses water for irrigating the green evapotranspiration. Irrigation demands are areas around Villas, this average consumption calculated using the standard United Nations can grown to more than 1000 l/cap/day. This Food and Agricultural Organization (FAO) is a very high rate of use, with USA use rates method summarized in Crop evapotranspiration in Abu Dhabi & Adaptation for & of about 300 l/cap/day and Europe 125, l/cap/ - Guidelines for computing crop water day. By simply multiplying per capita use by requirements (Allen et al. 1998). population, the total residential water use in The WEAP representation of the eastern 2003 was about 280 Mm3, which represents region of Abu Dhai Emirate is shown in the about 45% of the desalinized water use. figure above Figure 4-2, and includes several Government and commercial use another 45% municipal/industrial demand nodes (e.g., and outdoor watering of gardens the remaining Swehan, Al Shoosh and Al-Ain); and catchment 10% of desalinized water. To reflect government, nodes representing irrigation demands (e.g., Impacts, Vulnerability
commercial, and other outdoor uses, we have Water Resources Al Shoot Irrig, Al Ain_Irrigated, Al Khazna Ag, simply doubled per capita use to 1100 and 900 etc.). The eastern-most portion of the study l/cap/day in the western and eastern regions, domain includes a representation of the Oman respectively. Mountain Wadis, and natural recharge to the In this table, per capita consumption reflects shallow, freshwater aquifer (green square just residential uses and is estimated simply labeled Shallow E FR) occurs via a runoff link as the product of population and per-capita (blue dashed arrow) from Shwaib_Hayer_ water use estimates. Government, schools, Swehan Irg object, leakage from the Swaib and commercial uses are assumed to double Dam object, which represents all surface water this rate (Abu Dhabi Water and Electricity, storage in Abu Dhabi, with a total capacity of 26 Regulation and Supervision Bureau). The mcm. This leakage rate was assumed as 20% of per-capita consumption rate is doubled in the the previous month’s storage in the reservoir. It WEAP model to reflect all M&I uses. was assumed that only the East-Fresh aquifer is a renewable resource and undergoes modern- When different outdoor demands are served day recharge via the Oman Mountains to the by different supply sources or have different west of Al Ain. priorities, another ‘Green Circle’ is introduced into the model. These catchment nodes (Figure Other aquifers represented include those 4-1 inset; green dots) represent land cover water characterized by shallow brackish water demands, including outdoor irrigation. For (Shallow E BR), shallow saline (Shallow SA); and example, the Abu Dhabi Irg node represents deeper sources such as East Aquitard Saline and the outdoor amenity water and agricultural Brackish. It was assumed that only the Shallow irrigation for the commodities represented in East-Fresh aquifer is a renewable resource and the model. The ‘Green Dot’ labeled 'Al Whathba' undergoes modern-day recharge via the Oman Forest represents the planted trees outside the Mountains to the west of Al Ain. This recharge main municipal area, which receive the same is represented by the Shwaib_Hayer_Sweihan sources of water as the 'Abu Dhabi Irg' but have Irg node, that in WEAP includes a natural, un- a lower priority (Priority 2) for receiving water. irrigated land class which applies the same FAO
Table 4‑2. Municipal and industrial water demand, 2003.
Population Per capita demand (l/cap/day)
Western 655,000 550
Eastern 533,000 450
105 Figure 4 3. The directory tree in WEAP, suggesting the data structure used to represent M&I demands (‘Red Dots’) and Figure 4‑2. Eastern region supply and Irrigation Demands (“Green Dots”) demand representation in WEAP.
hydrologic model that simulates monthly runoff Eastern region on the border with Oman to Swaib Dam as simply Runoff (mm/month) and also as a large basin in the Liwa – Beda = min(0,Precipitation – Evaporation). Swaib Zayed area. Only 22% of the fresh water is Dam is used to represent all surface water in the eastern region, where modern-day, storage in Abu Dhabi, with a total capacity of alluvium recharge occurs, accounting for 26 Million Cubic Meters (MCM). Water stored roughly 4,000 Mm3 of renewable volume in behind the Swaib Dam is recharged back to 2003. Table 4-3 summarizes the 2003 estimate the ‘(Shallow) (E)ast (FR)esh’ aquifer, with an of total available groundwater supplies. Saline assumed recharge rate equal to 20% of that held groundwater sources are assumed not used to in storage from the previous month, taking into meet M&I or irrigation demands and we have account evaporation from the water surface of assumed somewhat higher amounts of Eastern the reservoir. Brackish and Western Fresh groundwater than A 2003 estimate of groundwater resources is reported in Table 4‑3 but is consistent with suggests that fresh groundwater sources higher availability volumes that have been constituted only 7% of the total available reported by the Groundwater Assessment supply (see Section 2.1) as belts along the (GTZ et al. 2005) Programs.
Table 4‑3. Total supplies represented by the WEAP model. (GWAP/ G72,2005)
Fresh Brackish Desal (mgd) (Mm3) (Mm3)
Eastern* 4 128 528 Western 12.5 80 101
*Only the freshwater in the eastern region, near Al Ain can be considered “renewable”. All other groundwa- ter is mined.
106 Climate Change Impacts, Vulnerability & Adaptation 4.4. Representing Irrigation In the Abu Dhabi Emirate, Kc values are Demands typically much less than 1.0, as deficit irrigation is the norm given the scarcity of water. Irrigation demand for the three main irrigated Irrigation efficiency is simply the percentage land use types (e.g. agriculture, forests, and of water that is delivered to demand site but amenity) in the WEAP model is driven by climate. does not serve a beneficial use to the crops. Irrigation requirements for a demand site are A 90% irrigation efficiency implies that 10% computed using the FAO crop requirements of the delivered water is lost in transmission method, which assumes a simplified hydrological and/or lost to evaporation in a way that does in Abu Dhabi and agro-hydrological process. Parameters and not benefit the plant. Seasonal variation in Kc Adaptation for & variables used in computing crop water demand values is implemented to represent the reality include precipitation, evapotranspiration, crop that winter irrigation is more substantial than coefficients, irrigation efficiencies, leaching in summer, as more farmers fallow land in the factors, total planted area, fraction of planted summer due to the intense heat and resulting area per crop type, a crop coefficient (Kc), inefficiencies. Irrigation efficiencies were irrigation efficiency, leaching factor, and fraction assumed to range from a low of 70% for ‘Rhodes planted. Grass’, which assumed irrigation inefficiencies through transmission and application losses, Impacts, Vulnerability Agricultural irrigation demands represent the Water Resources 85% for ‘Forests’ and a high of 90% for ‘Amenity’, largest single use of water in Abu Dhabi Emirate. as trees and gardens are typically water with In WEAP, these demands are represented for the hand placed, drip irrigation. eastern and western region by disaggregating farms into three representative crop types, The leaching fraction represents an increase in including ‘Date Palms’, ‘Rhodes Grass’, and crop water demand to help leach salts from the an ‘Other Crop’ category that would include soil column. A leaching fraction of 0.2 indicates things like vegetables and grains. Evaporative that an additional 20% of crop water demands is demand or Precipitation Shortfall for each crop needed to help in soil-salt management. These is estimated in WEAP based on the estimate of coefficients used in the WEAP application for PET, the crop coefficient, irrigation efficiency, the five plants are summarized in Table 4‑4. and a leaching factor. The crop coefficient, The ‘Amenity’ type is a generic category of Kc, is used to characterize the degree to which land cover that represents green spaces, parks, irrigators apply water to their crops to satisfy gardens, etc. that have been planted around crop water demand. For a given crop, a Kc of the Abu Dhabi Emirate. We have assumed 1.0 implies that 1) the crop is fully watered, that the Kc value of the Amenity land cover is so evapotranspiration is limited by energy relatively high, consistent with the overall policy availability; and 2) the evapotranspiration of keeping those spaces green. The ‘Forests’ rate equals that of a “reference” crop, which is plant type represents planted trees that have typically alfalfa. been established throughout the country. For
Table 4‑4. Irrigation coefficients for the five represented crops/plants.
Irrigation Leaching Crop/Plant Kc Efficiency % Fraction %
Forests (trees) 0.2 85 5
Amenity 0.6 90 2
Ag-Date Palms 0.4 80 20
0.7 (winter) Ag-Rhodes Grass 70 20 0.5 (summer)
Ag-Other 0.6 (winter); 0.4 (summer) 80 20
107 mm/month mm/month (prcp)
Figure 4‑4. Al Ain “average” monthly PET and rainfall over the period 1994-2005.
this cover it was assumed that the Kc value 4.5. Calibration using observed is relatively low, implying a general strategy data of under-watering. The Forests land use type makes use of the same crop demand model Having described the general approach to used for the Agriculture and Forestry objects in estimating M&I, agricultural, amenity and the WEAP model. forestry water demands, we now summarize WEAP’s ability to replicate the broad annual Potential evapotranspiration (PET) is estimated water supply and demand for two select years, using the well known Penman Montieth 2003 and 2005. We have chosen these two years method (FAO-56) and are given in units of mm/ since they correspond to water reporting month. The PET was computed from monthly years available from the Department of Water observations of average air temperature (OC), Resources at ERWDA. Table 4-4 summarizes relative humidity (RH), wind speed (m/s), the reported water use by sector for 2003 and and solar radiation. In addition, time series of 2005 (gray columns); and the corresponding monthly total precipitation were used to modify modeled water use (columns labeled crop water requirements, although in this hyper- “Model”). arid region, annual evaporation demand far exceeds annual precipitation, and so the benefits Our estimates of Municipal and Industrial from rainfall in terms of satisfying crop water water use are less than the reported water demands are very marginal. Figure 4‑4 shows a use, but are consistent with the per-capita plot of the average monthly PET estimate for and population estimates given for 2003 and the coast (Abu Dhabi) and Interior (Al Ain). 2005. The discrepancy is likely due to other The coastal PET value is substantially lower uses of desalinized water that are part of the than the interior, as the high RH suppresses reported estimate, including irrigation. Our PET, while lower RH and substantially higher 2003 estimates of agricultural, water, and air temperatures raises PET in the interior of amenity uses closely match observations, while Abu Dhabi Emirate. Figure 4‑4 also includes our 2005 estimate of these same sectoral uses a plot of “average” monthly rainfall over the is about 15% higher than those reported. This period 1994 through 2005 for Al Ain, and should discrepancy is a result of higher evaporative be referenced with the right y-axis of the figure. demands in 2005 relative to 2003, which Annual rainfall is only about 1% of annual PET increased modeled irrigation requirements in on average. all sectors. In addition, there is a reported 40% reduction in the western forestry sector “due
108 Climate Change Impacts, Vulnerability & Adaptation Table 4-5. Comparison of Historical Estimated and WEAP Modeled Demands.
East (Mm3) West (Mm3) TOTAL (Mm3) 2003 Obs Model Obs Est. Model Obs Est. Model Est. M&I 152 152 428 320 580 472
Agriculture 1109 1200 840 770 1949 1970
Forestry 123 115 484 445 607 560 in Abu Dhabi & Adaptation for &
Amenity 111 114 134 134 245 248
TOTAL 1495 1581 1887 1669 3381 3250
East (Mm3) West (Mm3) TOTAL (Mm3) 2005 Obs Obs Model Model Obs Est. Model Est. Est. Impacts, Vulnerability M&I 111 170 641 351 752 521 Water Resources
Agriculture 980 1230 760 750 1740 1980
*Forestry 125 115 237 488 363 603
Amenity 118 124 137 154 255 278
TOTAL 1334 1639 1775 1743 3109 3382
*The Environment Agency of Abu Dhabi reports a substantial reduction in forestry in the ‘Uo El Dabsa Plantation’ in 2005.
mostly to the down-scaling of the Uo El Dabsa and the sectoral demand. plantation”, which we did not assume. Figure 4-6 shows that WEAP allocated about The allocation algorithm in WEAP automatically 78% of the total delivered water supply from allocates water supplies to the various demands, brackish groundwater sources, 3% from fresh with results of that allocation from the 5 year groundwater, and 13% from desalinized water, simulation (2002 through 2006) summarized in while reused water made up about 6% of the Figure 4‑5 and Figure 4‑6. total supply. These results are fairly consistent Figure 4‑5 shows the WEAP estimate of total with the supply make-up shown in Table 2.1. It annual demand for the agriculture, amenity, is important to realize that the WEAP allocation forestry, and M&I demands for the years 2002 algorithm is making the allocation “decision” through 2006. This simulation assumes that from the various supply sources to the demand the M&I demands increase only due to the sites based on demand priorities and supply growing population, as per-capita demands preferences made a-priori. were fixed over the simulation period. For the The WEAP-based, climatically driven water agriculture, forestry and amenity demands, it resources model of the ADE adequately reflects was assumed that the cropping pattern and the spatially and temporally specific water cropped area did not change, thus the year- supplies and demands. This model was used to-year variability are only due to climatic to simulate future water demands and supplies variability. The figure includes the total based on Scenarios and assumptions about annual potential evaporative demand for future climate, population growth, per-capita these two years to illustrate the magnitude of the climatically forced fluctuation of PET. water use, and sectoral demands. The Scenarios, There is a strong correlation between PET assumptions, and results are described below.
109 Annual Demand
Figure 4‑5. WEAP estimates of total annual water supply used to meet the demands.
Annual Supply Delivered by Source
Figure 4‑6. WEAP model estimates of total annual demand (left axis) and potential evapotranspiration (solid line, right axis).
110 Climate Change Impacts, Vulnerability & Adaptation 4.6. Scenarios and Key in the 40-year projections. Scientists agree on Assumptions some of the important broad-scale features of the expected hydrologic changes, the most It is impossible to know definitely the path of likely of which will be an increase in global economic growth, demographic changes, water average precipitation and evaporation as a use patterns and priorities, etc. throughout direct consequence of warmer temperatures. the ADE over the next 30 to 40 years. For this Regional changes, however, are more uncertain reason, the analyst must make assumptions and in fact could be quite different from region- regarding the future and then investigate what to-region, with some place experiencing more in Abu Dhabi those assumptions might mean for the water and others less precipitation. Generally, Global Adaptation for & supply and demand balance. In this study, Climate Models agree that the mid-latitudes these assumptions are bundled into a set of and sub-tropics will be warmer. Scenarios that fall into three broad categories, Climate Scenarios are rooted in downscaled labeled “Optimistic”, “Pessimistic”, and General Circulation Models (GCM), which “Middle-of-The-Road”. For each of these three provided a maximum and minimum projected broad Scenarios, we will make assumptions change in temperature & precipitation for Abu about the drivers of future water demand, Dhabi in 2050 and 2100. Below, we report the including population growth rates, per-capita Impacts, Vulnerability projected maximum/minimum changes for 4 Water Resources water use, and climate change. Accompanying Scenarios (A1, A2, B1, and B2). For each of the these drivers are assumptions regarding 4 Scenarios (A1, A2, B1, and B2), the projected future water use priorities such as possible maximum/minimum changes are based on reductions in agriculture and amenity watering, 5 GCM outputs (CCC196, CSI296, ECH496, and future water supply sources such as new GFDL90, and HAD2TR95) area as follows: desalinization capacity or the development of strategic reserves through aquifer storage and These projected climate changes are used as recovery projects. These later assumptions will guidelines in the development climate change be referred to as “adaptation options”, and will Scenarios that are used by the WEAP model be included as part of our Scenarios, which are to simulate ADE water supplies and demands. summarized in the scenario matrix of Table 4‑8 We developed three climate change sequences, (Page 113). The study horizon for our analysis given as time series of monthly mean air is 2008 to 2050. temperature and total monthly precipitation for the period 2005 through 2050. While GCMs 4.7. Developing Climate Change are able to simulate large-scale climate features Scenarios realistically, they typically exhibit biases at regional-scales. The regional biases are As explained previously, there is strong scientific problematic for analysis of climate implications consensus that the earth has been warming, for hydrology and water resources (Maurer, that this warming is driven substantially by 2007). human emissions of greenhouse gases, and that Recognizing the regional limitations of GCMs warming will continue. Climate models project has led to the application of “downscaling” that temperatures will increase globally by 1 as a means of trying to understand how local to 2ºC in the next 20-60 years. The projections scale processes, of greater interest to water are fairly consistent for the next 20 years, with resource planners, might respond to larger- a 1ºC increase, but exhibit larger uncertainty scale weather and climate changes (Wilby et al., 2004). Regardless of the technical approach, Table 4‑6. 5 GCM outputs projected maximum/ the primary goal is to process or interpret the minimum changes. GCM output so that it reflects the large-scale features and temporal trends from the GCM Temperature Precipitation simulation, but also the historical patterns +1.7 to 2.7°C (2050) -21% to +10% (2050) of climate variables at the regional and local scale (Wood et al., 2004). Downscaling can +3.1 to 4.8 ° C (2100) -38% to +18% (2100). produce more sub-regional detail and eliminate
111 system biases between observed local climate warming and a 20% decrease in total annual and climate generated by GCMs. Downscaling precipitation, with the best-case or optimistic does not necessarily provide more reliable scenario includes a more modest 1.0ºC warming information nor increase our confidence in a and 10% increase in precipitation over the next particular GCM scenario for climate change. 50 years. Note that because of the extreme aridity in the UAE, the optimistic scenario of Downscaling techniques generally fall into a 10% increase in precipitation is practically several classes, including simulated (dynamical), insignificant, while a 20% decline in precipitation statistical and bias-correction/disaggregation, suggests that the ADE would continue to and sensitivity methods. Dynamical downscaling need to manage its water resources from the involves the use of regional climate models run perspective of even greater aridity. No scenario at a relatively high resolution over a limited suggests that the future climate change will area with boundary conditions (and sometimes mean increased renewable water supplies for interior domain information as well) prescribed the ADE. from the lower resolution GCM. Statistical downscaling methods involve deriving statistical Climate change will likely have its most relationships between observed small-scale important impacts if there were substantial (often station level) variables and larger (GCM) warming in the winter months, as the summers scale variables, using analogue methods are already extremely warm and dry. Climate (circulation typing), regression analysis, or change could mean more winter season neural network methods (Mearns, 1999; Yates evaporative demands and thus more water et al., 2003, Clark and Hay, 2004). demands for the domestic, amenity, and agricultural sectors. This sensitivity analysis Our climate Scenarios are based on repeating was used to understand the response of the the observed climate from 1994 through 2008, hydrologic system to a warmer climate, with but then adding an absolute, random change particular emphasis on water demand. in temperature (T’ = dt + T) and a percent In an effort to make the scenario analysis change in precipitation P’ = dp*P to the efficient and informative given the broad range historical record. This results in new time series of GCM results and the uncertainty in future of temperature and precipitation for the period socio-economic conditions, we developed three 2008 through 2050, with changes in temperature categorical Scenarios which attempt to bracket and precipitation bound by the magnitude the range of possible future climate and socio- of the changes suggested by GCMs. These economic outcomes referred to as: Optimistic, Scenarios are akin to a sensitivity analysis of Pessimistic, and Middle-of-the-Road. The climate change, as we are assuming that the Scenarios are explained in more detail in the climate of the past repeats itself into the future, following section but are summarized here by with a predefined, albeit random, change in Table 4-7, and Figures 4-7 and 4-8. temperature and precipitation dictated by GCM results. In Figure 4-7, we graph the average monthly temperature for the Middle-of-the-Road For the worst-case or pessimistic scenario, the (MOR) scenario for both the coastal (light climate models suggest a 2.7ºC annual average blue) and interior (dark blue) areas. A 5-year moving average is included in the plot to Table 4‑7. Summary of climate changes included in demonstrate the embedded warming trend of WEAP modeled scenarios. about 2ºC for this scenario. Figure 4-8 graphs Climate Changes over 1961-90 precipitation trends for all Scenarios, including baseline Climate Out- Temperature Precipitation the “Optimistic”, “Pessimistic” and “Middle-of- come Change change the-Road”. 1) Optimistic + 1.7oC +10% 4.8. Summary of Modeled 2) Pessimistic + 2.7oC -20% Scenarios 3) Middle of the Road + 2.2oC +5% Using Optimistic, Pessimistic, and Middle-of- MOR) the-Road assumptions about future climate as
112 Climate Change Impacts, Vulnerability & Adaptation Avg. Monthly Air Temperature - MOR Scenario in Abu Dhabi & Adaptation for & Impacts, Vulnerability Water Resources
Figure 4-7. The average monthly temperature for the Middle-of-the-Road (MOR) Scenario.
Annual Precipitation Scenarios
Figure 4‑8. Total annual precipitation for the three climate change Scenarios.
113 well as water demand and population growth, very water use intensive, the question of long- we developed three unique Scenarios that were term sustainability of groundwater resources analyzed as part of this study to establish a range is critical. Current irrigation practices in these of plausible, future water balance conditions sectors suggest that non-renewable groundwater throughout the ADE including: supplies could be pumped dry through the next few decades. Much of the adaptation strategies Optimistic - lower population growth rates, modeled include decreasing amenity area and improved per capita demand, moderate summer watering (when evaporation and climate change temperature are highest), decrease forestry Pessimistic - more warming and extreme and agricultural area, layered on top of different climate change, high population, not as suggested population growth rates and per successful per capita-use reductions capita consumption rates.
Middle of the road - ‘business as usual’ growth rates with ‘expected’ or average 4.8.1. The Optimistic Scenarios climate projection (1, 1.1, and 1.2)
In addition, we have developed and run five The Optimistic Scenarios embed lower other Scenarios which tier off of the three population growth rates, more success in baseline Scenarios, making assumptions about reducing per capita demand, and moderate future adaptations to reduce water demand. future climate warming. The idea behind this The paragraphs below include descriptions of Optimistic Scenario was to model stated policy all the Scenarios that were created and analyzed objectives, optimistically assuming they will be as part of this study, as well as summaries in successfully implemented, and then layering Table 4‑8, Page. 113. climate change on top of those assumptions.
The Scenario drivers included assumptions Given the current rate of population growth about population growth (column 2), per and aggressive development policies, one capita demand (column 3), and climate change could imagine a Scenario where population (column 4), and a set of adaptation options growth rates stay very high into the middle (column 5). For the Optimistic Scenario (1), we of the 21st century, but water conservation have assumed that a high population growth programs achieve some success in reducing rate of 8% per annum continues until 2015, with per-capita demand, amenity water use is the rate decreasing to 4% through 2025 and then curtailed through fallowing of planted area to 2% for the remainder of the study period. This and summer time irrigation is reduced as a Scenario assumes that conservation programs strategy to just maintain green-space viability are successful and per capita water demand through the extreme summer heat. Reductions for domestic, industrial, and garden watering in agriculture and forestry water demand are is reduced to 800 l/cap/day by 2010 and then to achieved through reductions in planted area 700 l/c/day by 2012 according to stated policy of 30% after 2015. Scenario 1.2 makes the same objects, with this demand rate continuing assumptions as Scenario 1.1, but without through the end of the study period. Note that climate change to better illustrate the relative this still is an extraordinary per-capita rate. impact of climate on overall demand. The climate change assumptions are shown 4.8.2. The Pessimistic Scenarios in column 3, with a 1.7ºC warming through 2050 and a 10 increase in precipitation for the (2, 2.1, and 2.2) Optimistic Scenario. The Pessimistic Scenarios assume greater Many if not all of the Emirate’s water shortage climate warming, high population growth issues are demand driven, so we have modeled rates, and marginally successful per capita- adaptation strategies accordingly while use reductions. For the Pessimistic Scenario operating in the context of possible climate (2), it was assumed that population growth changes by 2050. For example, given that the continues at a rate of 8% per annum until 2015, amenity, forestry, and agriculture sectors are tapering off to 6% thereafter. This Scenario
114 Climate Change Impacts, Vulnerability & Adaptation Table 4‑8. Summary of scenarios used in Abu Dhabi Emirate climate change analysis.
Scenario Drivers
Scenarios Domestic Water Annual Pop’n Climate Change Use (liters/cap/ Adaptation Options Growth Rate1 (2050) day)
8,4,2% 800 (by 2010) 700 + 1.7oC over 1961-90 hi to 2015 (by 2012) [in line baseline, 1) Optimistic None med to 2025 and with stated policy +10% precipitation low to 2050 objective] over 1961-90 baseline in Abu Dhabi & Adaptation for &
+ 2.7oC over 1961-90 1100 all years 8% to 2015, then baseline decline 2) Pessimistic (behavior None 6% thereafter -20% precipitation doesn>t change) over 1961-90 baseline
1100 to 2015; 8,6,4% +2.2oC over 1961-90 900 from 2015 3) Middle of the hi to 2015 baseline through 2020 None Road (MOR) med to 2025 and +5% precipitation then 800 through low to 2050 over 1961-90 baseline Impacts, Vulnerability 2050 Water Resources
Decrease amenity 1.1) Optimistic 8,4,2% 800 (by 2010) 700 + 1.7oC over 1961-90 area and summer + reductions in hi to 2015 (by 2012) [in line baseline, watering by 20%; amenity, forestry med to 2025 and with stated policy +10% precipitation decrease forestry and and ag water use low to 2050 objective] over 1961-90 baseline agricultural area by 30% after 2015
Decrease amenity 1.2) Optimistic 8,4,2% 800 (by 2010) 700 area and summer No warming with adaptation, hi to 2015 (by 2012) [in line watering by 20%; No trend in no climate med to 2025 and with stated policy decrease forestry and precipitation change low to 2050 objective] agricultural area by 30% after 2015
2.1) Pessimistic Decrease amenity + Municipal 1100 to 2015; + 2.7oC over 1961-90 area and summer Demand 900 from 2015 8% to 2015, then baseline watering by 20%; Management, through 2020 6% thereafter - 20% precipitation decrease forestry and reductions in then 800 through over 1961-90 baseline agricultural area by amenity, forestry 2050 30% after 2015 and ag water use2
Decrease amenity 2.2) Pessimistic area and summer No warming with adaptation, 8% to 2015, then 800 (by 2010) 700 watering by 20%; No trend in no climate 6% thereafter (by 2012) decrease forestry and precipitation change agricultural area by 30% after 2015
1100 to 2015; 3.1) MOR with no 8,6,4% 900 from 2015 No warming climate change hi to 2015 through 2020 No trend in None Reference med to 2025 and then 800 through precipitation Scenarios low to 2050 2050
Notes * per-capita use is domestic, industrial, and outdoor uses by citizens. ** Per capita demands uses a factor of 2 to reflect industrial and outdoor uses. (e.g. 550 l/c/d * 2). *** "Domestic water us when modelled in line with stated policy objective is not considered an adaptation strategy except for Scenario 2.1 where pessimistic population growth is counter balanced by suggested per capita reductions"
115 also assumes that conservation programs are include a 2.2ºC warming through 2050 and a mostly unsuccessful in reducing per-capita 5% increase in annual precipitation relative to demand. The climate change assumptions the 1961-90 baseline. Scenario 3.1 tiers off of include a nearly 2.7ºC warming by 2050 relative Scenario 3, but assumes no warming in order to to the historic baseline, with the ADE becoming assess the relative impact of climate change on even more arid due to a 20% decline in annual water demand (see further explanation in the average precipitation. Reference Scenario).
Scenario 2.1 assumes the same adaptations as Scenario 1.1 (reductions in amenity and 4.8.4. The Reference Scenario (3.1) agricultural water use), but differs from the To demonstrate the marginal impact that optimistic baseline Scenario implying greater climate change has on water supply and demand reductions in domestic water use. Scenario relative to the other drivers of population 2.2 tiers off Scenario 2.1 but without climate growth, per-capita demand, and water use by change to illustrate the relative impact of the amenity, forestry, and agriculture sectors, climate on demand. Scenario 3.1 tiers off the MOR Scenario but assumes no future climate change. This final 4.8.3. The Middle of the Road Scenario was also run, assuming no change in Scenarios (3) per-capita demand, no reductions in sectoral use, a continued population growth rate of 8%, The Middle-of-the-Road (MOR) Scenario (3) and no climate change. With no assumptions assumes that population growth is high, but about future conditions considered and current considerable measures are taken to reduce patterns of use and population growth assumed, the recent high population growth, as rates this was referred to as the ‘reference’ Scenario quickly fall from 8% then 6% per annum, with and suggests an extreme future total water a final rate of 4% through 2050. The climate demand condition. change assumptions for the MOR Scenario
116 Climate Change Impacts, Vulnerability & Adaptation 5. Results and Discussion
The climate change assumptions for the three water use and amenity, forestry, and agriculture main Scenarios are reflected in the previous water use patterns remain at current levels section in Table 4‑8, column 3. To remind you, through the full simulation period. While the over the 1961-1990 baseline, the optimistic Reference Scenario is highly unlikely, it does climate change Scenario models a 1.7ºC warming suggest an upper bound on future water needs in Abu Dhabi through 2050 and a 10 % increase in precipitation if there were no policy interventions. Adaptation for & for the optimistic Scenario; the pessimistic The Optimistic Scenario (1) suggests a future Scenario models 2.7ºC warming through 2050 ADE population of nearly 7,000,000 by 2050, and a 20 % decrease in precipitation; while the requiring more than 5,000 Mm3 of water annually. middle of the road (MOR) scenario models Despite reductions in per-capita water use 2.2oC warming through 2050 and a 5% increase assumed in the Optimistic Scenarios, overall in precipitation. Many if not all of the Emirate’s water demand increases, driven by population water shortage issues are demand driven, so we growth in the M&I sector. The Optimistic have modeled adaptation strategies accordingly Impacts, Vulnerability Scenario with adaptation (1.1) suggests that Water Resources while operating in the context of possible future total water demand could be kept near climate changes by 2050. current levels even with substantial population 5.1. Water Demand growth. Reductions in water demand from the three big outdoor users (agriculture, amenity Figure 5‑1 shows the total annual water demand and forests) saves more than 1,000 Mm3 per year projections for all Scenarios through the end when compared to the Optimistic Scenarios of the simulation period (2050). The total without these adaptations. Future climate water demand is computed as a requirement, change in the Optimistic Scenarios results in but does not necessarily reflect the amount of a relatively small increase in water demand of water supplied to meet those demands. Total about 3% by 2050 (1.2), and thus a comparison demand ranged from a low about 4,000 Mm3 for of all three Optimistic Scenarios suggests that the Optimistic Scenario with adaptation (2.1) societal adaptations to reducing water demand to more than 18,000 Mm3 for the Reference will likely be more important than future Scenario, where population growth, per-capita warming.
Scenarios of Future Annual Water Demand for the ADE
Figure 5‑1. Total annual water demand estimates for the nine Scenarios.
117 Future climate change in the Optimistic 2.1 and 2.2 include adaptations in the form of Scenarios results in a relatively small increase reduced per-capita demand and reductions in in water demand of about 3% by 2050 (1.2), outdoor irrigation from the amenity, forestry and thus a comparison of all three Optimistic and agriculture sectors. These adaptations Scenarios suggests that societal adaptations reduce annual water demand to about to reducing water demand will likely be more 8,000 Mm3, suggesting the importance that important than future climate warming. Figure reductions in per-capita and other sectors 5‑2 summarizes the demands for the four sectors water use would have on overall water demand for this Scenario. Note that the adaptation throughout the ADE. Note the marginal impact does lead to reductions in agriculture water of climate change on total water demand, with demands. The plot includes the projection of the increase in demand attributable to climate future agriculture demands without climate warming of about 3.7%. change influences and suggests that warming increases agriculture demands by about 7% by For the MOR Scenario, population grows to the middle of the 21st century. Climate included more than 13,000,000 million, and while there changes in the forestry and agriculture demands are per-capita demand reductions, they are not are about 5% (not shown). substantial enough to reduce overall demand, which grows to about 7,000 Mm3 by 2050. With Population under the Pessimistic Scenario no adaptations in the other demand sectors (2) grows to more than 20,000,000 by 2050, (amenity, forestry, and agriculture) all water and combined with high per-capita use, demand growth is attributable to M&I demand. M&I demands outpace the demands of the Climate warming induces a 4.3% in total water other three sectors (amenity, forestry, and demand, with increased, intensive outdoor agriculture), with total annual demand nearing water demand. 12,000 Mm3 by 2050! With the same assumptions about future population, Pessimistic Scenarios The Middle of the Road Scenario (3) puts the
Future Water Demand by Sector
Figure 5‑2. Water demands by sector for the Optimistic Scenario with Adaptation and climate change (1.1). The plot includes future agriculture water demands without climate change (1.2), suggesting an approximate 7% increase in agriculture demands due to climate warming alone by 2050.
118 Climate Change Impacts, Vulnerability & Adaptation total water demand estimate at about 7,000 5.2. Water Supply Mm3, which is more than double the current In WEAP water demand is computed as a total estimate, with nearly all the demand growth requirement based on the given assumptions, occurring in the M&I sector. Comparing the but this requirement does not necessarily two MOR Scenarios (with and without climate reflect the amount of water delivered to meet change) suggests that warming leads to a those demands. To supply the computed water marginal increase in total water demand by needs, water infrastructure is represented in 2050 of less than 5%. the model that includes desalinization plants, Not surprising, all Scenarios suggest that in Abu Dhabi pumps, treatment facilities, groundwater Adaptation for & future population, per-capita water use, and aquifers with a assumed capacity, a distribution future decisions about outdoor irrigation of network, etc. Certainly in the UAE, water supply the agriculture, forestry and amenity sectors capacity and availability constrains the amount will most likely dominate total water demand. of water delivered to the various end-uses. Climate change, manifesting itself primarily as Quantifying this “unmet demand” is of course climate warming, will likely increase demand subjective. For example, in the agriculture, by less than 5%, which is small relative to the amenity and forestry sector, the vegetation changes from the other factors. The water and crops that have been planted could most Impacts, Vulnerability demand estimates just presented are based on certainly use more water to be healthier and Water Resources the assumption that there is water available more vibrant, but in the hyper-arid environment to meet those demands, with the demands of the ADE, it makes sense to deficit irrigate, computed from assumptions that include as water is simply to precious (and expensive). population, per-capita use, climate, and the In WEAP, the difference between the computed irrigation strategy for each outdoor use. Since “demand” and the model based allocation of WEAP tracks both the demand and supply supply to meet those demands (e.g. “Supply sides of the water accounting ledger, we now Delivered”) is referred to as “Unmet Demand” investigate these Scenarios from the supply or the supply deficit (Figure 5‑3). Since the side of the equation. M&I sector is nearly 100% reliant on desalinized
Future Water Supplies
Figure 5‑3. Supply allocation for Optimistic Scenario with Adaptation-
119 water to meet its demands, Unmet Demand for To continue to support irrigated agriculture this sector can be thought of as “additional where brackish groundwater sources are desalinization capacity needed”. For the inadequate, irrigation requirements are made- forestry and agriculture sector that rely on up through pumping of saline groundwater groundwater, “unmet demand” suggests the supplies. Fresh groundwater supplies remain non-sustainability of the water use activity and/ nearly constant, as they have been constrained or the overdrafting of groundwater aquifers. to make up only 10% of the total groundwater supply in WEAP, otherwise the alluvial, For the analysis of water supply, we will focus freshwater aquifers in the western portion of on the Optimistic with Adaptation (1.1) and the ADE would be quickly overdrafted. Once the Pessimistic with Adaptation (2.1), where this 10% of demand is met through the fresh both include their respective climate change groundwater resource, brackish and then saline forcing. From this analysis, it is very apparent groundwater sources can supply the remaining that unless future per-capita water use is not irrigation needs. substantially curtailed, future demands will only be met through increased desalinization WEAP assumes that all sources can adequately capacity, while the agriculture and forestry supply crop water requirements, as WEAP sectors would increasingly need to turn to makes no distinction between water supply type, more saline groundwater to meet irrigation except the distinction of preference from which requirements. Renewable freshwater resources supply to draw from first (e.g. first brackish in the eastern portion of the ADE are simply and if there is an inadequate supply, then draw not substantial enough to be considered a from the saline groundwater). The supply major contributor to the future water resource allocation for the Pessimistic with Adaptation portfolio on the ADE. (2.1) Scenario is nearly identical to Scenario 1.1 because we have constrained supply to current In Figure 5-3, desalinzed water supply grows levels (e.g. no change in desalinized water or up to its currently installed capacity but then waste water treatment expansion). capacity does not change over study horizon. Fresh groundwater resources remain constant. Figure 5.4 shows the estimated unmet demands
Total Unmet Demand
Figure 5‑4. Total unmet demand for the Optimistic and Pessimistic Scenarios with Adaptation.
120 Climate Change Impacts, Vulnerability & Adaptation for the Optimistic and Pessimistic Scenarios 5.3. Groundwater Supplies with Adaptation (1.2 and 2.2, respectively). Both Scenarios suggest substantial unmet In the WEAP model it is necessary to define the demand for the M&I sector, which can be initial storage state of each of our aquifers at the used to quantify the amount of desalinization start of the simulations. We have represented capacity that would be necessary to meet future the alluvial fresh and brackish aquitards of demands. These Scenarios imply a need for both the eastern and western regions, and it is additional desalinization capacity of more than our understanding that different organization 5,000 Mm3 and 1,000 Mm3 for the pessimistic and research groups over the years have drawn in Abu Dhabi and optimistic Scenarios, respectively. different conclusions regarding the available Adaptation for & volume of fresh and brackish groundwater. No Unmet demand in the amenity sector drops one debates, however, that the groundwater to near zero after 2016 in response to the being used, whether fresh or brackish is reductions in summer-time irrigation and effectively being mined as there is no substantial, reductions in planted area. While there is less modern-day recharge of the groundwater shortage in the agriculture and forestry sector, systems of the ADE except for a small amount demands still go unmet. Renewable freshwater in the extreme eastern region, as groundwater resources in the eastern portion of the ADE are throughflow from the Oman Mountains. Brooks Impacts, Vulnerability simply not substantial enough to be considered Water Resources et al reported a mean annual total of 31 Mm³/yr a major contributor to the current or future estimate of groundwater entering the Emirate water resource portfolio on the ADE. The only as groundwater, with the largest contribution way to continue to supply irrigation water to occurring within Wadi Dank catchment, the agriculture and forestry sector at current benefiting the area around Al Quaa. Recall that levels would be to increase the use of more saline groundwater or perhaps bank unused, the current water demand for the ADE is more desalinized water that would normally be than 3000 Mm3/yr, so only about 1% of current wasted to the ocean in an aquifer storage and demand is supplied with a “renewable” supply. recovery (ASR) scheme in well suited alluvial Our analysis has assumed that for the year 2002, deposits interspersed throughout the ADE. there is about 350 Bm3 of brackish and fresh
Total Fresh and Brackish GW Storage
Figure 5‑5. Fresh and brackish groundwater storage over the study horizon for all three Optimistic Scenarios.
121 groundwater available, excluding an assumed only concerned with growth in the urban sector, fresh groundwater source in the western the groundwater storage results for all three region of the country, near Liwa and Madinat of those Scenarios are nearly identical to the Zayed. This number is higher than the estimate Optimistic Scenarios results just presented. reported in Table 2.1, but research by GTZ suggests a substantial freshwater lens in the 5.4. Adaptation and Mitigation to western region that is partially taken to account Climate Change: Hand-in-Hand here. Future analysis could, of course, modify this assumption. Brooks et al. note that “the The analysis just presented suggests the likely GWRP calculated a total groundwater reserve range that climate change and other socio- of 253 Km³ (7% fresh, 93% brackish) and the economic factors will have on the water supply- GWAP total estimate of 640 Km³ (2.6 % fresh, demand balance in the ADE. Given the current 18.1 % brackish, 79.4% saline) is much larger state-of-the science with regards to future since groundwater of salinity of up to 100,000 climate, the analysis reports assumptions mg/l TDS was included, whereas the GWRP about future per-capita demand and population included groundwater with less than 15,000 growth, and the priorities and policies associated mg/l TDS”. The GWRP assessment (USGS, with agricultural production and development 1996) projects that the fresh and brackish will overwhelm the impacts of climate change on the water resources sector. While this likely groundwater resources will be depleted in 50 the case, the analysis drives home the point years at current groundwater abstraction rates. that serious consideration should be given to Their analysis does not include the freshwater the long-term goals and sustainability of the sources in the western region. Given our initial agriculture and forestry sectors. If these sectors estimate of fresh and brackish groundwater, continue to use water at their current rate, these resources would be depleted in about they will continue to strain a limited resource. 150 years given current extraction rate from Climate change will only hasten that position. the agriculture and forestry sectors of about 2,500 Mm3/year. This variance highlights the On the M&I side, “if freshwater supply has importance of the assumptions regarding the to be replaced by desalinated water due to current fresh and brackish groundwater supplies climate change, then the cost of climate change in determining their long-term availability. includes the average cost of desalination, which is currently around US$1.00/m3 for seawater and Figure 5‑5 shows the total storage of the US$0.60/m3 for brackish water (Zhou and Tol, fresh and brackish groundwater for the three 2005). The cost for freshwater chlorination is Optimistic Scenarios. In the analysis, only the approximately US$0.02/m3” (IPCC SRES, 2008). agriculture and forestry sectors are depending Water conservation will be needed to avoid the on groundwater as their supply source. continued expansion of desalinization capacity, Interestingly, the relative difference between since increased dependence on desalinized the Optimistic Scenario with adaptation and No water is sub-optimal. Climate change (1.1) and the same Scenario that Increasing desalinization capacity would seem assumes no climate change (1.2) are only slightly to be a quick and easy adaptation to future different, suggesting the marginal impact that demand, but it does not come without a cost from climate change would have on groundwater both a financial and environmental perspective. resources. The Optimistic Scenarios (1) does Increasing, to achieve water resource reliability, not include any reductions in agriculture or the water resources management strategy has forestry demand over the study horizon and also essentially been in investing in more energy imposes the moderate climate change forcing. to produce more water. But this option must However, as was just stated, the relative impact acknowledge that desalinization and the of climate change on groundwater storage is distribution of water accounts for a significant quite small, so all of the decline in groundwater share of total energy consumption, as power storage is attributable to the continued high plant emissions account for a significant share demand from the agricultural and forestry of Green House Gases (GHGs). Desalinization sectors. Since the Pessimistic Scenario is really is not a “Green” solution. Moreover, the latest
122 Climate Change Impacts, Vulnerability & Adaptation report of the IPCC holds out hope that global to re-examine their long-range objectives, warming can indeed be mitigated through GHG particularly in the forestry and agricultural reductions. The key for sustainable adaptation sectors, and continue to encourage water to climate change for the ADE should fully conservation. Likewise, the ADE is awash in incorporate the objective of reducing their renewable energy potential through solar or overall GHG emissions (i.e., reducing their wind-powered pumping, that would be both fuel “carbon footprint”) as an additional objective cost savings and would avoid GHG emissions. within their long-range water resource planning The challenge is to integrate such strategies strategy. Thus adaptation to climate change and within the water resource planning process to in Abu Dhabi mitigation of climate change must go hand-in- produce the best operating outcomes for the Adaptation for & hand. Perhaps the rising cost of electric power system as a whole in terms of cost, reliability will motivate ADE natural resource planners and social/environmental consequences. Impacts, Vulnerability Water Resources
123 6. Conclusions
Figure 6-1 summarizes the current average through the next few decades. To reduce the annual water demand estimates (2003 through rate of groundwater depletion, the agriculture 2008), and for four future Scenarios, averaged sector could consider adaptations such as over 2045 through 2050. A comparison of maintaining the culturally important date the Optimistic and Pessimistic Scenarios palm orchards and keeping some Rhodes grass highlights the need to curtail per-capita use for livestock feed, but fallowing field crops. in the M&I sector. The Optimistic Scenarios The forestry sector could realize substantial indicate increases in water use driven primarily reductions in a real extent of irrigated trees, by the M&I sectors, but also points to the fact with the sector focusing on those stands with that reductions in the agriculture and forestry the highest aesthetic and social service (e.g. sectors could keep future water use at near trees near public spaces and those close to current levels. Without strong reductions in roadways). For the amenity sector, there could per-capita water use and reductions in outdoor there be substantial reductions in green space irrigation in the forestry and agriculture sectors, watering during the summer months, and the the Pessimistic Scenarios suggest that future planting of species that can tolerate longer water demand could jump nearly three-fold by spells or go dormant without water. 2050, even with reductions in the agriculture and forestry sectors. While some gains could While the Arabian Gulf seems to be a source be made in reducing demands in the amenity of unlimited water, pollution by land-based sector, this sectors water use relative to the activity could increasingly impair the quality others becomes even smaller by 2050. of coastal water bodies that serve as feedwater for desalination plants. ‘Hot spots’ of marine Given that the amenity, forestry, and agriculture pollution are typically near centers of more sectors are very water use intensive, the question intense human activity such as the cities, of long-term sustainability of groundwater harbors and industrial areas of the ADE, which resources is critical. Current irrigation practices are also the areas where desalinated water is in these sectors suggest that non-renewable most needed for socio-economic development. groundwater supplies could be pumped dry Desalinization has been proven to be technically
Total Water Demand- 2045 - 2050 Average
Figure 6‑1. Summary of total water demand for the Optimistic and Pessimistic Scenarios, compared with simulated current water demands averaged over the period 2003 through 2005.
124 Climate Change Impacts, Vulnerability & Adaptation Table 6-1. Adaptation options for water supply and demand.
Supply-side Demand-side Prospecting and extraction of groundwater Improvement of water-use efficiency by recycling water Increasing storage capacity by building reservoirs and dams Reduction in water demand for irrigation by changing the cropping calendar, crop mix, irrigation method, and area planted Desalination of sea water Reduction in water demand for irrigation by importing agricultural products, i.e., virtual water Expansion of rain-water storage Promotion of indigenous practices for sustainable water use Removal of invasive non-native vegetation from riparian areas Expanded use of water markets to reallocate water to highly valued uses in Abu Dhabi Water transfer Expanded use of economic incentives including metering and pricing to encourage Adaptation for & water conservation feasible, but it is expensive from cost, energy, infrequently. Climate change may be only one of and ecological perspectives. The process of many drivers affecting strategies and investment desalination is not environmentally friendly and plans (and it may not be the most important seawater desalination plants also contribute to one over the short-term planning horizon), the wastewater discharges that affect coastal and partly due to uncertainty in projections of water quality. This is mostly due to the highly future hydrological changes. (IPCC SR Water, Impacts, Vulnerability Water Resources saline brine that is emitted into the sea, which June 2008) may have higher temperatures, contain residual Practices that increase the productivity of chemicals from the pretreatment process, heavy irrigation water use – defined as crop output metals from corrosion or intermittently used per unit water use – may provide significant cleaning agents. The effluent from desalination adaptation potential for all land production plants is a multi-component waste, with systems under future climate change (as well multiple effects on water, sediment and marine as in the instance of heightened agricultural organisms. It therefore affects the quality of the or domestic demand). At the same time, resource it depends on. Table 6‑1 suggests some improvements in irrigation efficiency are critical general adaptation strategies that have been to ensure the availability of water both for food identified by Working Group II of the IPCC in production and for competing human and the Fourth Assessment Report (IPCC, 2007). environmental needs (IPCC, 2007). The challenge, however, is that demand- There is high confidence that adaptation can side management options may lack practical reduce vulnerability, especially in the short effectiveness because they rely on the cumulative term. Water management in the face of climate actions of individuals. On the M&I side, public change therefore needs to adopt a scenario- education of water seems paramount to achieve based approach (Beuhler, 2003; Simonovic the kinds of per-capita water use rates that are and Li, 2003) as we have in our study. This is comparable to other countries of the world. being used in practice in countries such as the Supply-side options generally involve increases UK (Arnell and Delaney, 2006) and Australia in storage capacity or abstraction from water (Dessai et al., 2005). A second approach to courses and therefore may have adverse coping with uncertainty, referred to as ‘adaptive environmental consequences. Demand-side management’ (Stakhiv, 1998), involves the options may lack practical effectiveness increased use of water management measures because they rely on the cumulative actions of that are relatively robust to uncertainty. individuals. Some options may be inconsistent Integrated water resources management with mitigation measures because they involve should be an instrument to explore adaptation high energy consumption, e.g., desalination, measures to climate change, but so far it is in its pumping, and have so far been implemented infancy (IPCC SR, 2008).
125 7. References Allen, M., Stott, P.A., Mitchell, J.F.B., Schnur, IPCC SR on Water, (2008). “Climate Change and R. and T.L. Delworth (2000). Quantifying the Water” Technical Paper of the Intergovernmental uncertainty in forecasts of anthropogenic Panel on Climate Change Available from: http:// climate change. Nature, 407, 617-620. www.ipcc.ch/pdf/technical-papers/climate- Brook and Houqani (2003) “Assessment of the change-water-en.pdf Water Situation in the Western Region of the IPCC (2007) WGII, IPCC The Working Group II Emirate of Abu Dhabi. Available from http:// contribution to the IPCC Fourth Assessment www.ead.ae/TacSoft/FileManager/Publications/ Report. Working Group II: Impacts, adaptation reports/TERC/Inception%20%20Report%20 and vulnerability . Available online: http://www. Western%20Region.pdf ipcc-wg2.org/ Brook et al., (2005). Water Resources Of Jorgensen, D.G & Al Tikriti, W.Y, (2002). A Abu Dhabi Emirate, United Arab Emirates. hydrologic and archeological study of climate Environment Agency Abu Dhabi. change in Al Ain, United Arab Emirates. Global Bulloch, J. and Adel Darwish,(1993), Water Wars: and Planetary Change, 35 (2002) 37-49. (London, Gollancz. Karl, T.R. and K.E Trenberth. (2003). Modern (2008), CIA FACT BOOK. Global Climate Change, Science, 302(5651): Clark, M. P. and L. E. Hay. (2004). Use of medium- 1719 – 1723 range numerical weather prediction model Kiehl, J.T. and K.E. Trenberth. (1997), Earth’s output to produce forecasts of streamflow. Annual Global Mean Energy Budget, Bulletin Journal of Hydrometeorology, 5(1): 15-32. of the American Meteorological Society. 78: 197- Dai, A. (2006). Precipitation Characteristics in 208. Eighteen Coupled Climate Models, Journal of Mac Donald, M. (2004) Preliminary Assessment Climate, 19, 4605-4630 of the Water Situation in the Eastern Central Dincer, (1974) Region of the of Abu Dhabi” Emirate.
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126 Climate Change Impacts, Vulnerability & Adaptation CIA, (1990), Middle East Area Oil and Gas Map, Wangnick, K. ed., (1990) IDA; Worldwide Central Intelligence Agency map #801357, June Desalting Plants Inventory Report No. 1990 appendices 6 & 7. (Gnattenburg, Germany: Wangnick Consulting, 1989. Mote et al., (1999) Washington, W. (1996). An Overview of Climate Pan, Z., RW. Arritt, E.S. Takle, W.J. Gutowski, Modeling. In Final Report: An Institute on the C.J. Anderson, and M. Segal. (2004). Altered Economics of the Climate Resource, K.A. Miller Hydrologic Feedback in a Warming Climate and R.K. Parkin (eds.). Introduces a ‘‘Warming Hole.” Geophysical in Abu Dhabi Research Letters, 31:L17109. Wilby, R.L., S.P. Charles, E. Zorita, B. Timbal, Adaptation for & P. Whetton, and L.O. Mearns. (2004). Guidelines Pielke Sr., R.A., J.O. Adegoke, T.N. Chase, C.H. for Use of Climate Scenarios Developed from Marshall, T. Matsui, and D. Niyogi, (2007). A new Statistical Downscaling Methods. Report paradigm for assessing the role of agriculture prepared for the IPCC Task Group on Data in the climate system and in climate change. and Scenario Support for Impacts and Climate Agricultural and Forest Meteorology Special Analysis (TGICA). Available at http://www.ipcc- Issue, 132, 234-254. data.org/guidelines/dgm_no2_v1_09_2004.pdf Postel, S. (1999) Pillar of Sand: Can the Irrigation (accessed April 05, 2007). Impacts, Vulnerability Water Resources Miracle Last?, W. W. Norton & Company: 1999. Wood and Imes, (1995) Purkis and Riegl, (2005) Wood, A. W., L.R. Leung, V. Sridhar, and D.P. R. Seager, M.F. Ting, I.M. Held, Y. Kushnir, J. Lu, Lettenmaier. (2004). Hydrologic implications G. Vecchi, H.-P. Huang, N. Harnik, A. Leetmaa, of dynamical and statistical approaches to N.-C. Lau, C. Li, J. Velez, N. Naik, (2007). Model downscaling climate model outputs, Climatic Projections of an Imminent Transition to a More Change, 15(62):189-216. Arid Climate in Southwestern North America. Yagoub, M.M. (2004) “Monitoring of urban Science, Vol. 316. no. 5828, pp. 1181 – 1184. growth of a desert city through remote Tebaldi, C., R. L. Smith, D. Nychka and L.O. sensing: Al Ain, UAE, between 1976 and 2000” Mearns. (2005). Quantifying uncertainty in International Journal of Remote Sensing. 25 (6) Projections of Regional Climate Change: a 1063-1076. Bayesian Approach to the Analysis of Multimodel Yates, D., J. Sieber, D. Purkey, and A. Huber- Ensembles. Journal of Climate, 18(10): 1524- Lee, (2005a), WEAP21 a demand, priority, and 1540. preference driven water planning model: Part Trenberth, K. E., A. Dai, R. M. Rasmussen, and 1, Model Characteristics, Water International, D. B. Parsons, (2003). The changing character of 30,4, pg 487-500. precipitation. Bulletin of American Meteorology Society. 84, 1205-1217. Yates, D., D. Purkey, H. Galbraith, A. Huber-Lee, and J. Sieber, (2005b), WEAP21 a demand, priority, United Arab Emirates 2006, Initial National and preference driven water planning model: Part Communication under the UNFCCC 2, Aiding freshwater ecosystem service evaluation, US Geological Survey / NDC Administrative Water International, 30,4, pp. 501-512. Report (1994) Groundwater Resources of the Yates, D., S. Gangopadhyay, B. Rajagopalan, and Liwa Crescent Area, Abu Dhabi Emirate K. Strzepek. (2003). A technique for generating Vorosmart, C et al. (2000) “Global Water Resources: regional climate Scenarios using a nearest- Vulnerability from Climate Change and Population neighbor algorithm, Water Resources Research, Growth” Science Magazine Vol. 289. 39(7), 1199.
127 Annex 1: Data sources and key assumptions
Map 1...... 1 (EA) Reports1. We brought these EA maps as Map 2...... 1 .pdfs into GIS, geo-referenced them, and then created a separate ‘regional’ file for use when Map 3...... 130 calculating hectares per region of irrigated Map 4. WEAP Schematic and areas. Imported GIS layers...... 131 Map 5. Eastern Region, Figure A1-2 conveys the Abu Dhabi Emirate, irrigated areas and WEAP nodes...... 1 alone, a data layer that also includes the Map 6. Western Region, previously mentioned regional divisions within the Emirate. It also includes a simplified irrigated areas and WEAP nodes...... 1 depiction of the irrigated areas, farms, and Spatial Data Sources And forests layers provided by the Environment Agency. Assumptions Figure A1-3 is a map from the Environment Figure A1-1 is a general overview of the country, Agency. We used this as a base for placing including elevation data, Emirate capital city Desalination Plants and Waste Water Treatment points, and three regions used in discussion Plants (WWTPs) in our WEAP schematic. The used throughout the report as based on a map can be found in an existing Environment delineation in an existing Environment Agency Agency (EA) Report (Brook, n.d.).
Figure A1‑1. Overview Map
1Combined from Figure 31:Location of water sources and users in Abu Dhabi Emirate (2003) [Brook et al., 2005], and Figure 1: General Location Map for the Study Area [Dawoud et al.,] An ArcGIS Database for Water Supply/ Demand Modeling and Management in Abu Dhabi Emirate, UAE
128 Climate Change Impacts, Vulnerability & Adaptation in Abu Dhabi & Adaptation for & Impacts, Vulnerability Water Resources Figure A1‑2. Map of Abu Dhabi key Water Supply / Demand Abu Dhabi key Water A1‑2. Map of Figure
129 Figure A1‑3. Sources and Users of Water in Abu Dhabi Emirate. in and Users of Water A1‑3. Sources Figure
130 Climate Change Impacts, Vulnerability & Adaptation Data Sources And Assumptions • 2006water resources statistics-English • Additionally, water resource-specific spreadsheets on Desalination and Waste- We relied predominantly on the data provided water Treatment Facilities, e.g. ‘Water In- to by the Environment Agency. Including the formation of Existing Desalination Plants following spreadsheets (See table): in Abu Dhabi Emirate’ from AADC Well- • 2002 water resources statistics fields 2005.xcl • 2003 water resources statistics These are summarized in the tables bellow. in Abu Dhabi & Adaptation for & Table A1-1. Abu Dhabi Emirate groundwater reserves estimate from GWAP (GTZ, 2005a).
Volume of Drainable Groundwater (km3)
Total Fresh Brackish Saline Upper Aquifer (West) 221 12.5 70 138.5 Shallow Aquifer (East) 58 4 10.25 43.8 Western Aquitard (WA) 326.7 0 9.9 316.8 Eastern Aquitard (UF) 35.2 0 25.7 9.5 Impacts, Vulnerability Sum (km3) 640.9 16.5 115.8 508.6 Water Resources Percentage of Total GW: 100.0% 2.6% 18.1% 79.4%
Sum West (km3) 547.7 12.5 79.9 455.3 Percent West 85.5% 75.8% 69.0% 89.5% Sum East (km3) 93.2 4.0 35.9 53.3 Percent East 14.5% 24.2% 31.0% 10.5%
Table A1-2. Demand site assumptions.
Population (2001) DEMAND Growth(Key\Annual City Name Transmission Link à Return Flow à SITES Population Growth Rate[%]/100) Um Al Naar Desal Central/East Abu Dhabi 527000 Taweelah Desal Mafraq WWTP Mirfa Desal Madinat Zayed Madinat Zayed West 17869 Mirfa Desal settlements WWTP Taweelah Desal East Al Ain 328000 Al Ain WWTP Qidfa_Fujirah Desal Eastern Aquifer (BR) Al Khatim/Al Kha- East Khazna 102500 Um Al Naar Desal zna WWTP Eastern Aquifer (BR) Three Northern East Swehan 102500 Um Al Naar Desal WWTP Shuweihat_Ruwais Desal West Ghayahti Sett. 11377 Ghayahti WWTP Ghayahti WWTP West Al Mirfa 12325 Mirfa Desal Mirfa WWTP West Ruwais 19925 Shuweihat_Ruwais Desal Ruwais West Islands 13768 Shuweihat_Ruwais Desal Islands Other Western 34456 West Liwa Settlements Pop’n Mirfa Desal Liwa WWTP Muzayrah 4147 Liwa 13799 Qidfa_Fujirah Desal Three Northern East Al Shoosh Shallow East Aquifer WWTP (FR)
131 Table A1-3. Catchment site assumptions
CATCH- Sub Sector Area (Ha) Transmission Link à Return Flow à MENTS7 Amenity Al Khatim_AlKhazna 15691.89*Key\Irrigation\ Forests WWTP Planted\Forests; 11000 23000*Key\Irrigation\ Farms- Total Eastern Aquifer Al Khanza Planted\Farms; 34000 (BR), Al Khazna Agriculture Farms- Rhodes 40% ShallowEast (FR) Wadi Grass Farms- Date Palms 25% ShallowEast (BR) Farms- Other 25% ShallowEast (SA) Farms- Fallow 10% 4652.77+551.55*Key\ Amenity Irrigation\Planted\ Amenity Al Ain WWTP 1735.9+9711.52*Key\ Forests Irrigation\Planted\For- ests Eastern Aquifer Al Ain Irri- 4000.37*Key\Irrigation\ (FR), Al Khazna gated Areas Farms- total Planted\Farms Wadi Farms- Rhodes 40% Eastern Aquifer (BR) Grass Farms- Date Palms 25% ShallowEast (FR) Farms- Other 25% ShallowEast (BR) Farms- Fallow 10% ShallowEast (SA) Amenity 11000 Forests Farms- total 3100 Um Al Naar Desal Abu Dhabi Farms- Rhodes Irrigated 40% Al Wathba discharge Grass Areas Farms- Date Palms 25% Farms- Other 25% Mafraq WWTP Farms- Fallow 10% Amenity 12856.1*Key\Irrigation\ Forests Planted\Forests ShallowEast (BR) Al Shoosh Farms- Rhodes Eastern Aquifer Irrigated Grass (BR), Northern Areas wadi Farms- Date Palms Farms- Other ShallowEast (FR) Farms- Fallow Amenity 43949*Key\Irrigation\ Western Aquifer (FR) Forests Planted\Forests Madinat Farms- total Zayed Irri- Farms- Rhodes Madinat Zayed wadi 40% Western Aquifer (BR) gated Areas Grass Farms- Date Palms 25% Farms- Other 25% Western Aquifer (SA) Farms- Fallow 10%
132 Climate Change Impacts, Vulnerability & Adaptation Table A1-3. continued
CATCH- Sub Sector Area (Ha) Transmission Link à Return Flow à MENTS7 Amenity 38999*Key\Irrigation\ Forests Upper West (FR) Planted\Forests Farms- total Ghayathi Ir- Farms- Rhodes Ghayathi Wadi rigated Areas 40% Grass Upper West (BR) in Abu Dhabi
Farms- Date Palms 25% Adaptation for & Farms- Other 25% Upper West (SA) Farms- Fallow 10% Amenity 7186*Key\Irrigation\ Eastern Aquifer (FR) Forests Planted\Forests 32000*Key\Irrigation\ Farms- total Wagan Qua Planted\Farms Irrigated Wadi Dank Farms- Rhodes Areas 40% Grass Eastern Aquifer (BR) Impacts, Vulnerability
Farms- Date Palms 25% Water Resources Farms- Other 25% Eastern Aquifer (SA) Farms- Fallow 10% Amenity 15600*Key\Irrigation\ Forests Planted\Forests 19500*Key\Irrigation\ ShallowEast (BR) Farms- total Shwaib, Hay- Planted\Farms Shallow East Aqui- fer (FR), Northern er, Sweihan Farms- Rhodes 40% wadi Irrigated Grass Areas Farms- Date Palms 25% Farms- Other 25% ShallowEast (FR) Farms- Fallow 10% 3500 * 100 ; 3500 km2 * Natural 100ha/1km^2 Amenity 5000*Key\Irrigation\ Forests Planted\Forests 3000 * Key\Irrigation\ Ghantoot Farms- total Planted\Farms Al Wathba Dis- Samba Irri- Taweelah Desal Farms- Rhodes charge gated Areas 40% Grass Farms- Date Palms 25% Farms- Other 25% Farms- Fallow 10% Al Wathba 38999*Key\Irrigation\ Um Al Naar Desal Al Wathba Dis- Forest Planted\Forests Mafraq WWTP charge Amenity Forests Western Aquifer (FR) Liwa- Ham- Farms- total Western Aquifer mim Irri- Farms- Rhodes 40% (SA), Liwa wadi gated Grass Western Aquifer (BR) Farms- Date Palms 25% Farms- Other 25% Western Aquifer (SA)
133 Annex 2: Climate projections
GCM outputs for 2050 and 2100 population that peaks in mid-century and declines thereafter, and the rapid The climate projections used in the Water introduction of new and more efficient Sector Report were based on a Climate Change technologies. Major underlying themes Projections study that SEI prepared for the are convergence among regions, capacity Climate Change Executive Committee of the building, and increased cultural and social UAE in April 2006. For that study, the authors interactions, with a substantial reduction used the climate projection tools MAGICC in regional differences in per capita (Model for the Assessment of Greenhouse-gas income. The A1 scenario family develops Induced Climate Change) and SCENGEN (A into three groups that describe alternative Regional Climate SCENario GENerator) to directions of technological change in the establish the regional climate baseline (1960- energy system. When considering non- 1991) and project future regional temperature fossil intensive scenario subgroups, future and rainfall. MAGICC and SCENGEN are carbon emissions are among the midrange coupled, interactive software tools that can of the four storylines. be used to examine future climate change and its uncertainties at both the global-mean and A2 storyline: corresponds to a very regional-mean levels. The report provided a heterogeneous world with a strong summary of climate change projections for underlying theme of self-reliance and selected urban areas of the UAE. The focus was preservation of local identities. Fertility on four climate indicators, as follows: patterns across regions converge very slowly, which results in a continuously average temperature and precipitation increasing global population. Economic over the 1961-1990 period (annual and development is primarily regionally monthly) oriented and per capita economic growth average temperature and precipitation and technological change are more for the year 1990 (annual and monthly) fragmented and not as fast-paced as in the other storylines. Future carbon emissions average temperature and precipitation under this scenario are among the highest under climate change conditions (annual of the four storylines. and monthly values for the years 2050 and 2100) B1 storyline: this corresponds to a convergent world in which global average change in temperature and population peaks in mid-century precipitation under climate change and declines thereafter, as in the A1 conditions relative to the 1961-90 baseline storyline, but with rapid changes in (annual and monthly values for the years economic structures toward a service and 2050 and 2100) information economy, with reductions in There are a total of 36 IPCC emission Scenarios material intensity, and the introduction of included in MAGICC/SCENGEN See Table a widespread clean and resource-efficient A2-1. These IPCC emission scenarios are technologies that lead to a reduction in grouped into four major categories, each with energy and material use. The emphasis its own “storyline” of how global development is on global solutions to economic, paths could unfold and each with their social, and environmental sustainability, resulting annual emission levels (IPCC, 2000). A including improved equity, but without brief overview of each Scenario storyline is as additional climate initiatives. Future follows: carbon emissions under this scenario are among the lowest of the four storylines. A1 storyline: corresponds to a future world of very rapid economic growth, global B2 storyline: corresponds to a world in
134 Climate Change Impacts, Vulnerability & Adaptation which the emphasis is on local solutions HAD295 and HAD300 are GCMs developed at to economic, social, and environmental the Hadley Centre for Climate Prediction and sustainability. It is a world with Research, which is part of the Meteorological continuously increasing global population Office of the United Kingdom). at a rate lower than A2, intermediate levels of economic development, and less Each Scenario-GCM combination provides a rapid and more diverse technological different estimate of projected temperature change than in the B1 and A1 storylines. and rainfall due to the fact that underlying While the scenario is also oriented toward assumptions are different. A driving concern in Abu Dhabi environmental protection and social in using MAGICC/SCENGEN results was to be Adaptation for & equity, it focuses on local and regional able to adequately represent a plausible range levels. Future carbon emissions under this for the UAE regarding future temperature and scenario are among the midrange of the rainfall levels. For this reason, it was important four storylines. that the analysis consider a sufficient number of Scenario-GCM combinations that could Additionally, there are a total of 17 General provide a robust and defensible indication of Circulation Models (GCMs) included in future climatic conditions. For this analysis, MAGICC/SCENGEN. Each GCM represents the one Scenario from each of the four storylines Impacts, Vulnerability main components of the climate system in three was considered, and were each analyzed by Water Resources dimensions as simulated in computer modeling the five different GCMs, as summarized in experiments, yet are differentiated by a range of Table A2-2. Hence, the resulting scenario-GCM underlying assumptions they use. The models combinations come to a total of twenty. are named relative to the institution where the experiments have been conducted (e.g., The Scenario-GCM combinations can also be represented spatially using Geographic Table A2-1. Summary of 36 emission scenario Information Systems (GIS) software. Below and 17 GCM options. we include four maps depicting average change in temperature (AT) and precipitation (AP) IPCC Emission Scenario across the country based on A1B-AIM-HAD295 A1 A2 B1 B2 GCM Scenario-GCM outputs see Figures A2-1 to
A1ASF A2-ASF BA-IMA B2-MES BMRC98 A2-4.
A1B-AIM A2A1MI B1AIM B2AIM CCC199 The results in the Tables A2-3 and A2-4 provide A1B- A2AIM B1ASF B2ASF CCSR96 the maximum and minimum projected change NEW in temperature & precipitation for Abu Dhabi A1CAI ASGIM B1HIME B2HIMI CERF98 city in 2050 and 2100 that our model was based A1CME A2MES B1HIMI B2IMA CSI296 upon. The projected maximum/minimum
A1CMI A2MIN B1MES B2MIN CSM_98 changes are for reported for the 4 scenarios (A1, A2, B1, and B2). For each of the 4 scenarios A1FI-MI B1MIN ECH395
A1GAI B1TME ECH498 Table A2-2. Emission scenarios and GCMs A1GME GFDL90 used for the UAE. A1IMA GISS95 IPCC Emission Scenario A1MES HAD295 A1 A2 B1 B2 GCM A1MIN HAD300 A1B-AIM A2-AIM B1AIM B2AIM CCC199 A1T-MES IAP_97 CSI296 A1TAI IMD_98 ECH498 A1V1MI MRI_96
A1V2MI PCM_00 GFDL90
WM_95 HAD295
135 2.21 - 2.25
2.26 - 2.29
2.29 - 2.38
Figure A2-1. Temperature change (ºC) in 2050
3.64 - 3.72
3.73 - 3.79
3.80 - 3.91
Figure A2-2. Temperature change (ºC) in 2100
136 Climate Change Impacts, Vulnerability & Adaptation in Abu Dhabi & Adaptation for & Impacts, Vulnerability Water Resources
Figure A2-3. Precipitation change (ºC) in 2050
Figure A2-4. Precipitation change (ºC) in 2100
137 (A1, A2, B1, and B2), the projected maximum/ From these tables we derived two summary minimum changes are based on 5 GCM outputs tables to capture first the range of potential (CCC196, CSI296, ECH496, GFDL90, and changes, as suggested by the scenario-GCM HAD2TR95). [Maximum/minimum changes are combinations chosen and second, the average yellow-shaded and dark blue font]. projected change based on the range.
Table A2-3. Annual average maximum change, 2050 and 2100.
MAXIMUM PROJECTED CHANGES IN ABSOLUTE VALUES
Temperature (degrees C) Precipitation (%)
Year 2050 B2-AIM B1-AIM A2-AIM A1B-AIM A1B-AIM A2-AIM B1-AIM B2-AIM
Abu Dhabi 2.57 2.46 2.73 2.90 11.25 10.57 9.53 9.94
Year 2100 Temperature (degrees C) Precipitation (%)
Abu Dhabi 4.73 3.50 6.02 4.79 18.55 23.29 13.53 18.32
Table A2-4. Annual average minimum change, 2050 and 2100.
MINIMUM PROJECTED CHANGES IN ABSOLUTE VALUES
Temperature (degrees C) Precipitation (%)
Year 2050 B2-AIM B1-AIM A2-AIM A1B-AIM A1B-AIM A2-AIM B1-AIM B2-AIM
Abu Dhabi 1.68 1.61 1.78 1.90 -23.09 -21.71 -19.58 -20.41
Year 2100 Temperature (degrees C) Precipitation (%)
Abu Dhabi 3.10 2.28 3.93 3.13 -38.09 -47.81 -27.77 -37.61
Table A2-5. Summary of GCM Output Range for Abu Dhabi
Temperature Precipitation
+1.74 to 2.67°C (2050) -21.20% to +10.33% (2050)
+3.11 to 4.76 ° C (2100) -37.82% to +18.42% (2100)
Table A2-6. Summary of climate changes included in WEAP modeled scenarios
Climate Changes over 1961-90 baseline
Climate Outcome Temperature Change Precipitation change
1) Optimistic + 1.7oC +10%
2) Pessimistic + 2.7oC -20%
3) Middle of the Road MOR) + 2.2oC +5%
138 Climate Change Impacts, Vulnerability & Adaptation 139 140 141
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi 142 Figure Table 3-1:MajorlandtypesintheAbuDhabiemirate CO Asl MEA Km Km IPCC IIED IBAs Ha GIS GHG GEF GCM FAO EN Figure Figure Figure 2 2
7-1: Expectedchangesinannualtemperatureand 8-1: Themultiplestateecosystemrepresentation, 9-1: Theadaptivemanagementcycle, 7-2: Numberofclimatechangemodelsin ensemble average.Source:IPCC(2007)WG1 precipitation intheperiod2080-2099relativeto1980-1999, from Schefferetal.,2001 from Frankinetal.,2007 out of21independentmodels.Source:IPCC(2007)WG1 the IPCCreportwhichindicateanincreaseinprecipitation Above sealevel square kilometer carbon dioxide Millennium EcosystemAssessment kilomter Climate Change Intergovernmental Panel on Environment anddevelopment International Institutefor Important BirdAreas hectare Geographical InformationSystem green housegas(emissions) Global environmentfacility general circulationmodels Agricultural Organization United NationsFood and endangered species ...... List ofFigures List ofAcronyms List ofTables ...... VU UNFCCC UNEP UNCDD UKCIP UAE SRES Ppm PET NT NARS mm m ...... vulnerable species Convention onClimateChange United NationsFramework Programme United NationsEnvironment Combat Desertification United NationsConventionto Impacts Programme United Kingdom’s Climate United ArabEmirates Scenarios Special ReportonEmissions parts permillion potential evapotranspiration near-threatened species Systems National AgriculturalResearch millimeter meters Page Page
180 165 146 159 159 143
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi 1. Introduction
Abu Dhabi is one of seven emirates that together terrestrial surface, extending over a variety comprise the United Arab Emirates (UAE). The of terrestrial biomes which are extremely UAE has a total area of 83,600 km2 (8,360,000 ha), heterogeneous with wide variations in with Abu Dhabi being the largest, occupying topography, climatic, geological and biological an area of 67,340 km2 and representing 86.67% conditions (MEA, 2005). They are found on all of the total UAE area. The UAE is situated in continents in both the northern and southern the Eastern corner of the Arabian Peninsula, hemispheres and are home to more than 2 between latitudes 22 degrees and 26.5 degrees billion people or about one quarter of the earth’s north and longitudes 51 degrees and 56.5 population as well as many agricultural and wild degrees east. It is bounded by the Gulf of Oman crops centres of origin. They include important to the East and the Persian Gulf to the North ecosystems rich with unique and diverse Sultanate of Oman and Saudi Arabia to the communities of animals and plants. Some south, and Qatar and Saudi Arabia to the west. dryland ecosystems are exposed to a range of climatic and non-climatic factors and stresses The climate of the UAE is characterized by high that threaten their existence such as drought temperatures (up to 49˚C in July), high humidity and desertification, land degradation, pollution, and low rainfall. The average, annual rainfall competition with invasive species and climate in the mountain region (140-200 mm) and along change (UNCCD, 1997). the east coast (100-140 mm) is generally higher compared to the gravel plains (100-120 mm), Inspite of the many variations between with the west coast receiving the lowest average drylands in terms of level of aridity, elevation, of less than 60 mm (Boer 1997). The population geological and biological conditions, etc., they of the UAE has been growing very fast from share many common characteristic including; 2.41 million in 1995 to 3.77 in 2000 (Ministry of the low and erratic precipitation and high Planning, 2005) diurnal temperature variability. Moreover, dryland species and ecosystems have generally The term drylands is used to define the hyper-arid, developed distinct coping mechanisms to cope arid, semi-arid and dry subhumid ecosystems. with the harsh climatic conditions (low and Aridity zones as mostly used in the scientific erratic rainfall and high temperature). literature are derived from the area’s mean annual precipitation (p) and the mean potential People living in drylands, particularly rural evapotranspiration (PET), i.e. given as P/PET. communities, often rely on a combination This ratio is referred to as aridity index and is of rain-fed agriculture, livestock raising and used to classify dry lands as hyper-arid (ratio less other income generating activities that are than 0.05), arid (0.05 to 0.20), semi-arid (0.20 to extremely vulnerable to the climate change 0.50) and dry subhumid areas (0.50 to 0.65). impacts anticipated under most models. In some regions and due to the frequent and Drylands are particularly vulnerable to climate severe rainfall fluctuations soil formation change because of their inherent fragility that and water supply have already reached makes small changes in temperature and rainfall unsustainable levels (IIED, 2008). Dryland patterns a serious threat to their biodiversity. people historically managed to maintain and According to the IIED (2008), dryland regions sustain their livelihoods under the very difficult are expected to undergo significant climate conditions of the drylands, by developing very changes, but there is considerable variability unique coping strategies under both farming and uncertainty in these estimates between and pastoral systems. These systems are known different scenarios. The IPCC (2007), projected by their instability and high resilience and are in that dryland, particularly the deserts are going harmony with the basic properties of drylands to become hotter and drier. Based on UNEP which used to support the continued practice (2007), these changes are expected to impact of transhumance and of nomadism. Nomadic plant life and productivity through changing people adopt mobility and dispersion over wide growth conditions and increasing the risk grazing as coping mechanisms. Currently there of wildfires, which could change the species is a greater appreciation of the efficiency of composition and decrease biodiversity. traditional pastoral systems based on mobility Drylands occupy some 40% of the Earth’s and the exploitation of extensive resources (Niamir-Fuller, 2000).
144 Climate Change Impacts, Vulnerability & Adaptation il e mn te ims xeinig the experiencing biomes affectedlargestbiodiversitybe will change, and the ecosystems among be Mediterranean will and grasslands years 100 next predictthat dryland biomes such assavannahs, the over assess change to biodiversity (2000) Chapin and Sala by models Simulationaltitude.metersin 150 poles, or the displace terrestrial species some to 125 expectedkm towards Each is temperature in drylands. rise one-degree in productivity distribution reduced species and in climate shifts of predict change models Simulation biodiversity. drylandthreaten to expected temperaturesare regional or local in and patterns precipitation in changes Significant 2007). (IPCC,processes ecological dryland of determinants major are evaporation higher rates alia, and lower inter rainfall cause, both will of warmingwhich Climate biodiversity andrelatedecosystems. drylands the on impacts significant changes have could climatic projected and on-going the that indicated have studies capacity,many but etc. pressures (Edouard G, 2001). Inspite of this human-related high adaptive fires drought, variability, climate e.g. exposed frequently are to recover from the many stresses to which they capacity have and resilient more generally are drylands in prevailing ecosystems and Species development ontheplanet. human of sustainability that the compromise levels profound may at have biodiversity global to on impacts expected is the atmosphere in gases greenhouse of build-up the from The predicted global climate warming resulting 2. dryland ecosystems Potential risksto
changes expectedby2050(Nature,2004). eventually become extinct as a result of climate a sample of 1,103 land plants and animals would chance). A recent study suggest that 15–37% of in changes 10 of major out (8 function, and and structure ecosystem chance), 10 animals of and out plants (5 of percent 20–30 for risk observed significant extinction increased an is; most drylands in changes the among that, global to stated (2007) IPCC response The 2008). (IIED, warming a as direction expected the change of with consistent were changes systems, more than 89 percent of the significant 29,000 observed changes in terrestrial biological drylands of a an assessment increasing In significantly. being vulnerability of change capable climate factor major with land dry on many impacts that the increase to indicated interact could factors also report MEA The biodiversity 2005). (MEA, on rapidly change very increase will ecosystems all across climate of impacts Ecosystem projected Millennium the that noted also The has Assessment risk. at billion 1 people placing and people more million affecting 250 than directly degraded, drylands, are sub-humid world’s areas, dry and the semi-arid of arid, including cent per seventy (2005b), UNCCD the to According pressures. induced human and change climate of impacts Drylands are currently witnessing the combined and climatechange. significantly by a combination of land use change 145
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi 3. Terrestrial Ecosystems of the UAE
The terrain of Abu Dhabi is generally dominated waterbirds and conservation of the waterbirds by low-lying, sandy desert and salt flats and their habitats is an important element in the (sabkhas). In the eastern side there are the conservation of overall biodiversity of the country. Hajar Mountains which rise to more than 2,000 The Arabian Peninsula serves as a staging post meters. Satchell (1978) describes the UAE as between Africa and Asia for migratory species, having two distinct regions: and the many lagoons, mud flats, khors and An eastern mountain region: with a sub- mangrove stands found along the Persian Gulf montane zone of outwash plains characterised and the Gulf of Oman provide ideal nesting by Acacia tortilis. In the eastern region, the and feeding sites. With nearly 50% of all the barren, jagged mountains form part of the bird species on the Central Asian Flyway and Hajar range in neighbouring Oman; they rise rapidly to 1,300m and then descend to Share of Abu Dhabi a narrow coastal lowland plain along the Land type Emirate (%) Gulf of Oman. The northern ridges of these Shrub, savanna grass land 8% mountains, known as the Ruus al Jibal or Musandem, face the Strait of Hormuz and Barren or sparse vegetation 90% are in an enclave of Omani territory. The Wetlands and water bodies 1% highest peak is 2,087m, and the slopes drop Urban and built up area 0.1% precipitously, creating a highly irregular coastline with spectacular valley sand; Table 3-1: Major land types in the Abu Dhabi emirate (Environment agency). Western desert region: divided into a coastal belt and inland desert and scrub characterised covered under the Central Asian Action Plan by ghaf (Prosopis cineraria) trees. to conserve migratory waterbirds and their The natural landscape in both of these regions habitats found in the UAE, the region presents includes wide range of terrestrial habitat types, a bird watchers paradise, with over 400 bird which can be broadly classified as: species recorded.
inland sand sheets and dunes, piedmont The country assumes much greater significance alluvial and interdunal plains, to conserve waterbirds and their habitats (UAE, mountains and wadis, 2006) see also Annex 5 on wintering birds). An coastal sand sheets with dwarf shrub inventory of Important Bird Areas (IBAs) in the vegetation, Middle East showed this ecoregion to contain coastal and inland sabkha. 14 out of 33 areas identified in Oman, and 11 out of 20 areas in the UAE (Evans, 1994). Khor Other important man-made habitat types, such Khalba on the UAE's east coast, bordering as cropland, planted forests, oases and urban Oman, contains an endemic subspecies of the areas represent a relatively small area (see white-collared kingfisher (Halcyon chloris ssp Table 3-1). These major habitat types (see box kalbaensis), which is endangered, with only 44- 2 on % of ecosystem types) could be subdivided 55 pairs remaining at the site (Aspinall, 1996). into more specialized ones with unique abiotic Thirteen IBAs have been identified in the UAE, features, flora and fauna. The total protected almost all concerning island seabird colonies area of 14 sites in UAE is 25,000 Ha, representing and intertidal feeding sites for shorebirds (Evans 0.3% of total land in 2003. And the total number 1994). The UAE contains a significant population of breeding mammals during 1992-2002 is 34 of the Socotra cormorant (Phalacrocorax with 8 threatened species. nigrogularis) a species endemic to the Arabian According to Country Report for the Central Peninsula and listed as endangered on the IUCN Asian Flyway Overview, UAE is an important Red List (IUCN, 2001). The UAE has six of the area for the wintering, breeding and staging fourteen known breeding colonies in the world.
146 Climate Change Impacts, Vulnerability & Adaptation UAE coasts in many sites including Abu Dhabi Abu including sites many in UAEcoasts the along flourishing are mangroves that shows the substrate layers. A visual of inspections readily capacity water-holding the and inundation of extent and water frequency salinity, the substrate are: or coast specific the of along species distribution plant and abundance the different determine that factors main over the Among areas. dominating stands individual some with species of number high relatively a to habitat a presents it as productive more is vegetation coastal UAE, in sabkha, habitat terrestrial dunes, sand other to with Compared headlands. rocky low and cliffs and flats flats tidal coastal marsh, include beaches, rocky and sandy mats, cyanobacterial zone salt coastal the mangroves, of habitats Main coast (approximately75kmlong). uf os (0 k ln) ad h rcy and Ocean) (Indian rocky Oman of Gulf steep sometimes the and long), km (600 coast Gulf lowArabian are and areas sandy the coastal namely identified, separate Two east. the to coast Oman of Gulf the and north, the in coast for Gulf extends Arabian the comprises and km, UAE650 about mainland of coastline The 4.1. CoastalZones ecosystems. major these of each for will situation biodiversity section This and characteristics the on with distinct information provide ecosystems. and zones habitat major seven zones, have Researchers identified of coastal to mountains. variety the inlands a flat from has ranging emirate habitats, Dhabi Abu The 4. Abu Dhabi ecosystems in Major terrestrial h wne ris bt n eea trs the perennial grasses. terms, and shrubs general Dwarf by dominated in is vegetation but rains, after winter appear the that annuals of amount large a are home to a high diversity of plants, including coast the of dunes white The areas. wide over found frequently are qatarense Zygophyllum the inland, with less influence of sea the species Chenopods habitats coastal constitute the main dominant species. Towards saline more In a listingofimportantFloratheUAE). for 6 Annex (see Zygophyllum and aegypti-aca nul such annuals the is zone coastal the in species dominant Other Island. ht eut oe fe ocsoa rainfall occasional after come events. result that floorings periodic from formed sabkha, Inland surface. the to close lies table water the where areas in profound is salt of accumulation The vegetation. of type any support not can it sea– the of action tidal of means by formed surface sabkha the on salts of concentration high the Due to n.d.). (Aspinall, cover plant significant any of devoid usually is that desert encrusted salt- flat, to referring term Sabkha’Arabic an is 4.2. CoastalandInlandSabkhat beside some beside perennials Halophytic ireta cycloptera, Biernertia Suaeda 147
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi Plant species particularly halophytes found in woodland is observed. The acacia is found in the sabkha could only be found in the margins association with shrubs such as Lycium shawii are restricted mainly to the margins. Other and Gaillonia aucheri (= Jaubertia a.), as well species could grow only after heavy rainfall as the succulent cactus-like Euphorbia larica which dilute the concentration of salts. e.g and semi-succulent Ochradenus arabicus. Zygophyllum qatarense. Other species found in the alluvial plains 4.3. Sand Sheets and Dunes are the Prosopis cineraria and Acacia ehrenbergiana along with A. tortilis/ Scattered The majority of land in UAE is covered by sand in a few localities in the east of Abu Dhabi sheets and dunes particularly the southern A. ehrenbergiana is found in sandy to silty areas. Two types of sands are identified a) interdunal plains. The toxic species of Rhazya white coastal sands originated from marine stricta (‘harma’) which is generally regarded sediments. b) The yellowish to grey siliceous as a gravel plain species is usually found in the sands found mainly in large tracts of the inland east of the country. Its toxicity derived animals and are produced from the weathering of quartz. to shrink from grazing it, giving it the chance Coastal white sands are derived from recent to increase and dominate – to the extent that marine sediments and are rich in carbonate. its presence is usually regarded as a sign of Generally sand sheets absorb rain water and act land degradation that dominate after the as reservoirs for water in the short to medium disappearance of other species such as Acacia term. The most dominant plant species in the tortilis and Haloxylon salicornicum. Both sand of UAE is the Cyperus conglomeratus. Haloxylon salicornicum and Aerva javanica are often associated with Rhazya. Other associated perennials include Diptery- gium glaucum and Limeum arabicum. Cype- The other species that also indicate land rus being unplatable, was able to survive the degradation from heavy human disturbance is heavey grazing better than other species, such Calotropis procera (ushar), an extremely fast- as Centropodia forskaolii, Panicum turgidum growing tree that can begin producing flowers at and Pennisetum divisum. Observations in one an early age and found in the alluvial plains and of the protected ares (Al Wathba) have shown low dunes. Species like Haloxylon salicornicum that good germination of Cyperus occurs after is only slightly tolerant of salt and could be incidents of heavy rainfall in the late spring, replaced by other species like Zygophyllum when temperatures are already quite high qatarense as soil salinity increases. Other again. It also indicated the occurrence of many regular associates on interdunal plains include premature death of seedlings under insufficient the perennials Fagonia ovalifolia, a small rainfall during the sensitive early stages of its woody plant, Heliotropium digynum, found growth. South of Abu Dhabi City, some stands mainly on sandy interdune corridors, and H. of shrubby tree (Haloxylon persicum) (‘ghada’), acciferum, a plant that tolerates more saline, are found, mainly in the form of poorly estab- gravelly substrates. lished plant community. The interdunal plain which is already species- poor, is dependent on winter rainfall and in 4.4. Piedmont Alluvial and years of low precipitation its seedlings may Interdunal Plains not be able to germinate. Another factor that limits the growth of annual plant is the high soil The alluvial plains are found along the western salinity. Inland sabkha is frequently developed edge of the Hajar Mountain range. They consist in the interdunes, and vegetation may be of pebbles and coarse rock detritus at the foot completely lacking there. of mountains and sand and finer gravel further west, plus interstitial alluvium. Small trees, 4.5. Mountains and Wadis dwarf shrubs and succulents are the dominant plants in the alluvial plain. The north-eastern The Hajar range is the major mountain system part of the UAE is dominated by Acacia of south-eastern Arabia, about 20-50 kilometers tortilis (‘samr’)-the classic species of rocky wide dissected by numerous wadis, and reaches and gravelly plains. In the Madam Plain of East elevations of more than 1000 m. The mountain Coast a vegetation type similar to open Acacia extends some 700 km from the Musandam
148 Climate Change Impacts, Vulnerability & Adaptation by moving sand and become disconnected from up silted been dried, have wadis some flooding, and water of lack through and time, Over sea. wadis were originally river beds stretching to the Some Oman. and UAE the between route a as used is instance, for Qawr, Al Wadi between countries. even or villages, and towns mountains, between or travelling dunes a through as whether is route, wadi the of use traditional Another valleys. however,are Arabic, wadis the from translation literal the to the According word. of version Westernised the to according - or plain. In other words, wadis are watercourses lake sea, it be lead, they wherever to water the carry they resistance, least of course the being and, wadis these into runs areas surrounding by the Waterfrom weathering. caused and surface earth’s - areas the of dune movement the as such processes natural or plains or gravel - mountains in the in depression a is wadi A of number high species (UAE, relatively 2005). a by represented (Asteraceae ), Apiaceae) ( composites umbellifers and (Poaceae ) with grasses UAE, the types habitat in other to compared life plant of diversity highest the of one contains mountain The south-east. the in Oman) (eastern Sands Wahiba the to close to north the in Peninsula Adiantum capillus-veneris. by thefernAdiantumcapillus-veneris. accompanied typically watercourses, artificial and wadis of banks the along conditions shady UAE, white small numerous flowers. The only known species of with orchid in the plant lily-like a is years, drier in even common, particularly and annuals, of amount large a with flourish wadis the winters, wet In m. 1500 about to ascending tree common a as Zizyphus spina-christi (Christ’s Thorn), is found At lower altitudes, in wadis and on rocky slopes Lycium shawiiandGailloniaaucher. by accompanied frequently is and wadis many lower the in fringes. particularly biodiversity in rich being by characterized always are beds Wadi condition. climatic favourable such of presence fern bryophytes and the wide spread and of the lichens mountain particular in plants, poikilohydric of presence The altitudes. higher at plants of growth the for conditions climatic more favourable provide temperatures decreasing and precipitation increasing as temperature, and precipitation by determined is zone wadis and mountains in vegetation the terms, general In high in mountain situations. common locally are europaea) (Olea 1000 meters elevation. Further south, olive trees above vegetation the of constituent important the Arabian almond country, the of north-east far the In summits. the is mountains shrub the throughout Common cordata ssp. salicifolia become more dominant. like trees wadis, higher altitudes. On rock debris, especially near although increasing elevation, and is with rarely encountered above disappears 500 m, gradually species Acacia spinosa. C. and cartilaginea Capparis and chamaerapistrum Pulicaria glutinosa, Ochradenus aucheri, shawii, Physorrhynchus Lycium aucheri, Gaillonia accompanied by a number of perennials such as include the the slopes mountain lower the in species dominant in and Important Mountains emirates. the Hajar of parts to eastern restricted are Boer (1999) noted that large numbers of species flow intotheseaafterheavyflooding, however,Others, destination. still original their Onychium divaricatum are indicators for the trvs n moist in thrives veratrifolia, Epipactis , often reach up to the to up reach often viscosa, Dodonaea dominates the edges of edges the dominates tortilis Acacia remains common at much at common remains Euphorbia Acacia tortilis and and pere-grina Moringa (Amygdalus arabica) is an shdls tenuifolius , Asphodelus ehoi apollinea. Tephrosia Euphorbia larica 149 Ficus
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi 4.6. Freshwater Habitats and terraced fields. The field in the mountain is very Oases rich in wild species beside date palm plantations. In places with abundant water supply, farms Natural fresh water habitat is very rare in UAE have been established (e.g. Liwa), and fields and is restricted to the permanent streams and of Chloris gayana (Rhode’s grass) are spread pools present in the mountains. In such habitat around the country. Typical wildflower species of with highly moist conditions some aquatic the agricultural areas include Anagallis arvensis, plants are found such as Potamogeton lucens, Chenopodium murale, Eruca sativa, Euphorbia P. pectinatus, Najas marina and Zannichellia peplus, Fumaria parviflora, Melilotus indica, palustris. Arundo donax and Juncus. Heavy Portulaca olereaca, Oxalis corniculata, Rumex rain conditions could also lead to formation of dentatus, Sida urens, Sisymbrium erysimoides, temporary streams with wadis carrying flowing S. irio, Sporobolus spicatus, and Vicia sativa water. (Brown and Sakkir, 2004). Freshwater Oases exist throughout the UAE 4.7. Urban Environments on e.g. the plains on either side of the Hajar Mountains, and in many desert sites of Abu The vast urban developments in UAE Dhabi Emirate. The largest desert oasis is located have largely impacted the natural vegetation in the Liwa Crescent. It consists of a series of cover. However, a number of new species have individual oases spanning over more than 100 started to appear, making use of the inductive km. Oases in coastal plains are usually irrigated environment brought about by the afforestation by a ‘falaj’ system where the underground water programs and available irrigation water. Some of these plants are indigenous to the UAE, including is tapped from the edge of the mountains and Aeluropus lagopoides and Sporobolus spicatus then diverted along open channels to the oasis. (both common in irrigated urban areas), others This a 3000-year old system used in UAE. could be exotic such as Cressa cretica (garden In case of ‘ghayl’ system in the mountains, water beds), Coronopus didymus and Fimbristylis sp. is extracted from the upper reaches of the wadi (both locally abundant in lawns in Abu Dhabi), bed to be fed along open watercourses built Euphorbia prostrata, E. serpens and Sonchus into the sides of the wadi and then directed to oleraceus (Brown and Sakkir, 2004).
150 Climate Change Impacts, Vulnerability & Adaptation Walsh (1974) defines mangroves as a woodland a as mangroves defines Walsh(1974) 5.1. Mangroves subsequent the in sections. given is types faunal floral and some on details More invertebrates. of species 5,000 and 4,000 between and reptiles, of species of mammals, 416 bird species, 55 species to approximately 400 species home of vascular plants, 50 a is Dhabi Abu that indicated 2008) of the UAE. A recent study in Abu Dhabi (UAE, some hydrophytes in the inundated ecosystems and mountains, the of wadis in humid shaded the growing hygrophytes some are there Also, and halophytes. psammophytes annuals, xerophytes, (ephemerals, biennuals), therophytes shrubs, as the flora of the UAE mainly comprises thorny environments have arid their impact on the The plant structure and 1998). life, Sargeant, retention and (Boer matter water organic and low nutrients capacity, nature, sandy aridity, their Moreover,by characterized are UAE the of etc. soils the wadis mountain, coastal, e.g. types habitat different across scattered widely prevailing UAE is the the of flora the of conditions, like desert Because UAE. the within areas green urban and vegetation, palm date with oases several are there these, from Apart and wadis, desert rocky-mountainous vegetation. plain, gravel dune, sand swamp, reed marsh, salt mangrove, seagrass, according to the following ecological categories: UAEnatural the terms, classified be could flora general In periods. dry in disappear and rains after appear therophytes The therophytes. are greatest number of species recorded in the UAE the that highlighted they species, bryophyte 20 about to addition In Africa. and Asia both from more than630species,andcompriseselements and contains UAE the of flora the (1999), Boer developed, and has Kürschner to According emirate develop. to continues the which at rate rapid the to due primarily threat, under severe come have species and habitats Many species. animal and plant habitats, of variety Abu 5. Abu Dhabi Important florain b hs rmral nme and number remarkable a has Dhabi osby u t te as sme climate, summer harsh the to due possibly UAE,the in naturally Avicenniaoccurs marina mangrove, of species one Only 2001). Johnson, fishery and inincreasing (Laegdsgaard coastline the on production important are and fish juvenile for important refuge and protection provide They be coastal (Dahdouh-Guebas environments to to exporters and producers known biomass are Mangroves 2003). (Ning disturbance. the following recovery rates affecting stress thermal to led have 35°C Temperaturesabove Saenger,1993). and 1992; (Duke, temperature distribution mangrove as affect moisture such factors Climatic (McLeod ability dispersal affecting through distribution mangrove influence also may currents coastal and mixing tidal as such processes coastal that, known widely also is currents. It of action the by away seedlings the alluvial wash otherwise could that activity wave strong to exposed fine-grained not are that shores and a substrate require Mangroves ees f xgn n ntrly cu i the in occur naturally intertidal zones(Chapman,1976). and oxygen of levels low with sediments shifting salinity, water in fluctuations to adapted macroalgae and micro many and species tree woody of constituted is of characteristic tropical regions subject to marine, the action of tides. It and land between coastal ecosystems in a transitional environment formation below the high-tide mark. They exist in 2000). al. et ., 2006). al., et t al., et 151
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi although there is speculation that in the past, expected to impact the mangroves and the a second species, Rhizophora mucronata, also destruction of mangroves could also exacerbate thrived in some areas. the negative impacts of climate change on coastal ecosystems and infrastructure based on In Abu Dhabi Emirate, the main strands of a paper by IUCN (2006). Climate change impacts mangroves are found east of Abu Al Abyad on mangroves will not occur in isolation; the island, with isolated occurrences further response of mangroves to climate change will be to the west (for instance, just west of Jebel a result of these impacts acting synergistically. Dhanna). The trees rarely exceed 3 to 4 m in The paper stressed that the damage caused by height. The stands are much denser than any the tragic 2004 Asian tsunami was exacerbated mainland vegetation type in the Emirate, and by over clearing of mangroves and other coastal are extremely important habitats for marine life “bioshields”, inappropriate coastal development and many species of bird. The roots anchor the and inadequate information and preparedness. trees firmly in the mud, and the upper parts of the roots grow out of the water as characteristic 5.2 . Mountain and Jebel vegetation ‘pneumatophores’. Their primary function is to absorb air and transport it to the roots beneath Jebel Hafit, which is part of the Hajar mountain the water. Avicennia marina is a C3 species and range, is considered as the only true mountain transpires large amounts of water. Since the in Abu Dhabi Emirate, although part of it is uptake of dissolved salts cannot be reduced to located in Oman. It stands high above the any significant degree, the accumulation of toxic surrounding plain to over 1000 m asl. Jebel Hafit concentrations of salt in their aerial organs is is characterized by a least developed virgin soil potentially a serious problem for the plants. very rich in humus. The mountain is considered This problem has been overcome by the as the most important site within Abu Dhabi presence of salt-excreting glands on the leaf Emirate due to a number of characteristics, as surface, which results in the plants often coated briefly described below: in a whitish layer of salt. Climate change is highly rich floristic diversity, representing
152 Climate Change Impacts, Vulnerability & Adaptation pce ta ae tews asn fo the from absent otherwise are that nonhalophytic of species number a are present Also from thesurroundingsabkha. dust saline windblown the to due presumably and rosmarinus as such halophytes including jebels, interest. A number of plant island species occur on the typical research represent considerable of thus are Jebels and habitats m. 60 largest the to with high, up m 10 to 5 about to up typically are but height, and area both in vary tops flat with exposures rocky These sabkha. features. They are mostly surrounded by barren in coast the more western parts along of the Emirate as prominent found are jebels Tertiary well astheFicus johannisssp.. as mountain, the on locally occurs UAE, the in species rare a is which ritchieana Nannorrops orientalis trees were observed. The dwarf palm of group small a Tarabat, Wadi In habitats. sandy of characteristic otherwise mountain and the on include occurring shrubs Other the summit,andascendingrockycliffs. large, to up roadside the by and detected with leaves, leathery species populations a cartilaginea, large Capparis in locally occurring widespread, fairly is which exposed rubescens, Salsola the are on identified species Other shrub slopes. mountain dwarf common a is natural along channels. found drainage often is but altitudes, Euphorbia, t summit. the to close occurs still but frequent, elevation, as increasing such and perennials aucheri Gaillonia by accompanied often Hafit, Jebel of slopes lower the in widespread and tortilis Acacia distribution ofmanyglobaltaxa. the for limit western the represents site the of thetotalareaUAE small area which represents less than 0.002% very a within exist sp.) 380 (approx. Dhabi Abu in species known the of third one a over ecosystem; and or area other any to not and species these many of to habitat only the is mountain this a species a epapposum, Rhanterium eilc aphylla, Periploca og, ean cmo a all at common remains hough, Te aiiy is salinity The spp. Salsola aoyo salicornicum Haloxylon are larica Euphorbia eoe less becomes Acacia With shawii. Lycium rwa erythraea Grewia Acridocarpus Seidlitzia turgidum andPennisetum divisum . Panicum sp. by Indigofera comosum, accompanied Calligonum tops often jebels, the larger on some of dominant be rainfall. can heavy drummondii after jebels some of flanks the on abundantly appears erythraeum lily the Furthermore, hispidissima. Arnebia perennial facultative bristly, the and aegyptiacum Eremobium parviflora, Savignya as such annuals, desert of number a are plants the Among ones. larger the of plateaux the on gullies in or rocks behind accumulate that soil of pockets small in grow plants These area. surrounding as their floral composition. Floods can wash Floods composition. floral their as well wadi beds as characteristics physical their the of terms in habitats, dynamic highly it within influence creating flooding climate severe seasonal The the as such extremes microhabitats. and variability favourable of mosaic a create to All combine water. conditions these to access regular and light availability; microclimate; and microtopography in heterogeneity spatial significant of presence substrate; of types different of existence the to rich vegetation, particularly the lower ends due biodiversity their for recognized are Wadibeds 5.3. Wadi bedsvegetation n h salr ees a wl as well as jebels, smaller the on Dipcardi Salsola 153
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi away many plant species and at the same time flora as they provide good environment bring the seeds of new plants to grow in these for date plantations together with other unique microhabitats. Important grasses of agricultural crops (Brown 2004). Date palm wadi beds are Cymbopogon commutatus and C. plantations provide habitats for a number of schoenanthus, as well as Cenchrus ciliaris. wild plant species. Farms have sprung up in desert areas where there is a sufficient supply of 5.4. Flora of the oases water (e.g. Liwa), and fields of Chloris gayana (Rhode’s grass) are dotted around the country. The natural oases at Al-Ain and Liwa, which Typical wildflower species of the agricultural were the habitat for the earliest agricultural areas include Amaranthus spp., Chenopodium settlements in Abu Dhabi, are the largest in murale, Emex spinosa, Eruca sativa, Euphorbia the emirate, and they continue to expand with prostrata, Launaea procumbens, Melilotus irrigation. Some of the oases are naturally indica, Phyllanthus rotundifolius, Portulaca occurring, while others are man-made; however, olereaca, Sisymbrium erysimoides, Sporobolus generally they have similar wild and domestic spicatus and Trigonella hamosa.
154 Climate Change Impacts, Vulnerability & Adaptation conservation. Moreover, and beside the seabirds seabirds. important This makes it particularly important in terms of globally of and habitat breeding regionally a is Emirate Dhabi Abu flats, mud to coastal mountains andinlandwetlands. the from diversity habitats the to of related Emirate Dhabi Abu The Emirates. Arab relatively high number of species recorded from United the in recorded birds the all of 96% almost Emirate representing alone, Dhabi Abu in birds of species 416 of history natural various groups in the country. It indicated the of presence members been by and also ERWDA) have (formerly Dhabi Environmental Abu surveys the - Agency by birds’ recently of undertaken number A while 82%aremigratory. areresident 18% birds land identified 271 the 35% around with 65% about to reaching Emirates, in species of majority the constitute birds Land ravens. brown-necked small breeding populations in the desert, so are maintain to known also and are owls eagle Buzzards desert lark. finch black-crowned the and the courser cream-coloured as the lark, such hoopoe species desert-adapted Dhabi, Abu mostly in identified are birds of species and Various Emirate. Dhabi birds Abu the in mammals) (reptiles, biodiversity higher vertebrate overall of 81% nearly constitute Birds 6.1. Birds can befoundinthewild. and animals, domesticated as or either accidentally times, geological recent introduced under UAE been in have species 11 species, 41 remaining the From wild. the in extinct be to known are indica) Hystrix and nimr, pardus Panthera hyaena, Hyaena arabs, lupus Canis ibexnubiana, Capra aegagrus, Capra leucoryx, Rodentia, and Insectivora Chiroptera). Of these 48 species, 7 species Lagomorpha, (Oryx Perissodactyla, Hyracoidea, Artiodactyla, mammals These (Carnivora, Orders 8 Familiesof 18 within exist UAE. the in recorded been Forty-eight species of terrestrial mammals have 6. in AbuDhabi terrestrial ecosystems Fauna ofthe of water birds. Of birds. water of n Bonnce Raven(Corvus Brown-necked and aethereus) Red-billedTropicbird nigrogularis), Osprey Cormorant haliaetus),Socotra like species some still but bird species breed to during summer(May-August), taken protect been the avifauna of the Emirate. Most of the have measures conservation the in significant some it of species because and world, bird Arab valued highly the of one bustard of houbara wintering the hosted it colonies, breeding hayoi macqueenii, Chlamydotis (Phalacrocorax (Phaethon (Pandion 155
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi wadis and 5% are found in the desert habitat.
6.2. Threatened bird species
Several species found in the Emirate are regarded as internationally important or priority species, meaning they are [rare, threatened (globally or nationally) and have restricted breeding range]. Of the 15 species listed as ‘Globally Threatened’ by the BirdLife International in the UAE, four (4) are water birds and rest are terrestrial species. Of the 11 terrestrial only the Saker Falcon (Falco cherrug) is listed as endangered (EN), while species such as Houbara (Chlamdydotis macqueeni), Imperial Eagle (Aquila heliaca), ruficollis) breed during winter (November-April) Greater Spotted Eagle (Aquilaclanga), Lesser months. Seven habitat types are identified as Kestrel and Lappet Faced Vulture are listed as birds’ habitat in Abu Dhabi, mainly green areas vulnerable (VU). Five species are listed as near- with artificial plantations, gardens/parks and threatened (NT), includes Pallid Harrier (Circus wetlands. These habitats present the grounds macrourus), European Roller and Cinereous for feeding, resting and breeding of different Bunting (Emberiza cineracea). species of birds. 16% of the total bird species are found in the mountains, rocky habitats and The main threatening factors identified
156 Climate Change Impacts, Vulnerability & Adaptation the important Sooty Falcon, are particularly particularly predators are Falcon, Sooty certain important the with including falcons, and eagles as or birds such species shooting of the and hunting 2004) (IUCN, introduced of species birds migratory wild other by include Influenza Avian as identified habitat. such transmission disease threats ecological expected natural Other the impacted infrastructure which have directly or indirectly include the urban development and industrial of the Golden Skink (Mabuya aurata aurata 2004 (Soorae,2005). (Mabuya Skink UAE and was discovered on record Jernain Island in new the for Golden record a is new which a septemtaeniata) also the is There of snakes. and amphisbaenids They lizards, the by deserts. dominated in are known widely are Reptiles 6.4 the jerboaandseveralspeciesofhedgehog. the sand cat, Rueppell’s fox, cape hare and even in the Western region of the Abu Dhabi such as gazelle. Some of the nocturnal species are found mountain and sand the – Dhabi Abu in survive striped hyaena and over jackal. Two species of desert oryx, gazelle wolf, the include the These decades. last the in extinction suffered animals have of species are Several Dhabi goats. Abu and camels in fauna common most The 6.3. Mammals and habitats. presence their and birds of the distribution impact potentially that could factors the among mentioned been has change Climate practices. such to vulnerable . Reptiles 157
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi 7 Vulnerability assessment of Drylands ecosystems
This section will attempt to assess the of human activities on Earth since 1750 has vulnerability and impacts of drylands been warming. The report emphasized the high ecosystems with focus on Abu Dhabi emirates. uncertainties in prediction of arid ecosystem
It will present information on climatic changes, responses to elevated CO2 and global warming. potential impacts and adaptation measures for However, it projected a generalized warming of the drylands ecosystems. over 3ºC and a 100% increase in frequency of extremely warm years and the likely reduction 7.1. Observed Climatic changes in in rainfall in Southern Africa, Sahara & Central dryland ecosystems Asia and likely increase in West Africa, East Africa and South Asia (IPCC, 2007). An assessment by the IPCC of long-term trends in precipitation amount over many large 7.3. Current climate and expected regions for the period 1900-2005, indicated that climatic change in the UAE drying has been observed in the Sahel, the Mediterranean, southern Africa and parts of The climate of the UAE is characterized by high southern Asia. The report has also indicated temperatures (up to 49ºC in July), high humidity that more intense and longer droughts have and low rainfall. The average annual rainfall in been observed over wider areas since the 1970s, the mountain region (140-200 mm) and along particularly in the tropics and subtropics (IPCC, the east coast (100-140 mm) is generally higher 2007). These observations are linked to higher compared to the gravel plains (100-120 mm), temperatures, decreased precipitation; changes with the west coast receiving the lowest average in sea surface temperatures, wind patterns, and of less than 60mm (Boer, 1997). decreased snow cover. The IPCC groups the Saudi peninsula into the More relevant to dryland regions is that areas Asian division, a region expected to undergo a affected by drought have and will continue to wide range of climatic changes over the next increase (IPCC, 2007). Little was reported in century. An assessment by the IPCC of trends in the IPCC Working Group 2 report regarding precipitation for the period extending from 1900- the observed impacts on crops and livestock in 2005 indicated that drying has been observed in drylands or other developing country regions the Sahel, the Mediterranean, southern Africa (Rosenzweig et al. 2007). A study had shown and parts of southern Asia, regions with similar that very dry land areas across the globe climate characteristics to the peninsula. The (defined as areas with a PDSI of less than –3.0) IPCC reported that more intense and longer have more than doubled in extent since the droughts have been observed over wider areas 1970s, and this was associated with an initial since the 1970s, particularly in the tropics and precipitation decrease over land related to subtropics, but may have increased slightly in the El Niño-Southern Oscillation and with the Arabian Peninsula (IPCC, 2007). subsequent increases primarily due to surface warming (IIED, 2008). A recent consortium of climate scientists from the Middle East recently compiled a database 7.2 Projected climatic changes in of climate observations over the last half dry land ecosystems century, and reported that both maximum and minimum temperatures in the region have The IPCC (2007) has left no doubt that global shown a statistically significant increase and the warming is occurring and that climate change number days exceeding the 90th percentile have is human-induced, concluding that “warming of increased throughout the region (Zhang et al., the climate system is unequivocal” and stating 2005). However, the report indicates that there with 90 percent confidence that the net effect have been no coherent trends in precipitation
158 Climate Change Impacts, Vulnerability & Adaptation n rcptto ot f 1 needn models. Source: IPCC(2007)WG1. independent 21 of out precipitation increase in an indicate which report IPCC the models in change climate of Number 7-2: Figure ensemble 1980-1999, average. Source: IPCC(2007)WG1. to relative annual period 2080-2099 the a) in precipitation in b) and changes temperature Expected 7-1: Figure eisl wl eprec increasing availabilitywaterreducedandrunoff leadingto in experience (see Figure 7-1a), and may possibly Arabian see will decreases century next the over 3-5ºCtemperatures from the that peninsula project models Climate patterns thoughouttheregion. its already low precipitation (see Figure 7-1b), 7.4. show oppositedirectionsofchange. which Africa, Intertropical over the (ITCZ) Zone or Convergence Ocean, Indian and Arabian Sea the to linked be will region this over climate in shifts the if disagree models the of in UAE particular the (see Figure 7-2). It appears as and if many peninsula, Arabian the over trends precipitation for change of direction the on disagree models the half approximately that indicates are but Mediterranean, droughts the in severe expected that and 2007), Sea (IPCC, Arabian the over intensity in increase to likely very is monsoon summer Indian the that suggests report IPCC the example, El-Fadel, For 2002). and Bou-Zeid (i.e. literature the or models either in addressed explicitly rarely is region the and 2007), (IPCC, peninsula Arabian the in high change climate expected relatively in uncertainty is there that indicates report repeated are throughout the conclusions literature, the most recent IPCC same these While (Arnell, 1999;Millyetal., 2005). serious impacts on biodiversity as any changes any as biodiversity on impacts serious have could patterns rainfall in changes factor, water where areas In biodiversity. decrease and composition species the change could which wildfires, of risk the increase could temperature rising that and lands sub-humid and dry of biodiversity the on impacts serious have can patterns rainfall changes and temperature in small that noted 2007 UNFCCC- UNEP, NCs). IUCN, UNEP, (IPCC, ecosystems drylands to threat major a as and change climate highlighted national reports other assessment many international Emirates, the major in the ecosystems dryland as and biodiversity to threat interference human identify Although most of the available national literature different these sources ofstresses. to vulnerability the consider will section This systems. natural the impacted among themajorfactorsthathavesignificantly fast The development and land use change stresses. are identified multiple non-climatic to and exposure climatic of function a is Dhabi Abu in ecosystems terrestrial of Vulnerability ecosystems ofAbuDhabi Vulnerability of terrestrial is a limiting a is 159
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi in water availability could disproportionately aquifers. This will have implications on the affect human livelihoods. growth of important species and threaten their existence. Moreover, the impacts of climate change on drylands may have significant repercussions Non-climatic stressors can increase vulnerability on populations and economies particularly in to climate change by reducing resilience areas where people are highly dependent on (IPCC, 2007) e.g. human-induced degradation drylands biodiversity. In general terms, the of ecosystems may increase vulnerability to faster the climatic changes, the greater will be climate extremes. The MEA demonstrated how the impact on people and ecosystems (UNEP, drylands are challenged by the major drivers of 1997). Heat and water are limiting factors in the ecosystem services change – habitat change. dryland of the Abu Dhabi Emirate, and changes in temperature or water availability can have Many non-climatic factors are identified as disproportionate effect on its biodiversity. threatening the biodiversity in Abu Dhabi. UNEP also highlighted the fact that higher There is a general agreement that in addition to temperatures could threaten organisms that natural causes like drought, the main threats are are already near their heat-tolerance limits. coastal development and urbanization where 40% of the population is concentrated in the Decreasing precipitation could impair the two main coastal cities of Dubai and Abu Dhabi, growth of annual and perennials species in Abu accounting for about 60% of the population Dhabi, on which a large number of human and (Ministry of Information and Culture, 2006). animals depend. This link between rainfalls Overexploitation of natural resources (fishing, and plant growth in Abu Dhabi Emirate was hunting, over-grazing and water extraction) that illustrated by the observation that increase in are linked with the vast population increase and rainfall, over the spring of years 1982, 1983, and changes in lifestyle have also been identified as 1987 has been associated with the appearance a significant threat to biodiversity. of a greater number of perennials. This was further demonstrated by the wide spread of The fast economic growth without consideration Zygophyllum hamiense along the Abu Dhabi to the natural environment has been identified as to Al Hair road. Adverse impacts are observed one of the most important factors contributing during severe flooding where patches of eroded to destruction of biodiversity. Toreng et desert are exposed, linked to an increase in al., (2008) elaborated on the importance of waterborne particles and the disappearance of biodiversity in UAE and the threats it faces. some species of the natural vegetation, which They highlighted that, despite being regarded relies on a minimum soil depth (Western, 1988). as a vast deserted and unfertile area with one of Floral and faunal biodiversity in Abu Dhabi is the lowest human populations in the world, the expected to be affected by impacts on water UAE hosts a unique and remarkably adapted resources. A low rainfall future, would lead fauna and flora. (Boer, 1999), on the other to lower levels of surface runoff and less soil hand, listed domestic pollution, eutrophication, moisture that will impact the germination of reclamation, landfill and sedimentation, hunting, many plant species that are not particularly persecution, and unsustainable harvesting, alien adapted to drought, such as the wadi plants. introductions including predators on islands, The scarcity in plant species will affect the disturbance, mismanagement and development existence of animals that feeds on them and as among the main factors leading to habitat thus the whole food chain. and species loss. Decreasing precipitation could also lead Overgrazing to less recharged water and less available groundwater. The increasing temperatures Excessive grazing by camels is rated among associated with climate change would also the greatest threatened factors to the inland reduce water availability through increasing desert ecology of the UAE (Hellyer et al., 2001). potential evapotranspiration. Sea level rise Their severe impact was attributed mainly associated with climate change is expected to the rapid increase in their number since to lead to inundation and intrusion of salt the unification of the Emirates. Although water into important coastal ecosystems and the ecology of the region included grazing by
160 Climate Change Impacts, Vulnerability & Adaptation o uvv ad o opnae o te os in loss the numbers. for compensate to and survive to species the for chance a provide could grazing could also lead to loss of habitat, while moderate which grazing heavy by only reduced is species perennial of growth the that And herbivores. to impact time exposure short the to due season germination, of the significantly within plants to perennial or annual unlikely is grazing that indicated further study The 2001). al., et (Oba production maximize biomass and biodiversity plant maintain desert, to the of required be may grazing some that ecology indicating the grazing replenishing camel for the supports evidence Some (Gallacher etal,2008). movement their controlling regulations of lack considerations for camels have been behind the freely through graze out the and desert. move Social and to cultural allowed currently are that centuries, camels are the only domestic animals previous in herbivores large other and camels 00 Zaady 2000; al., et conditions. economic new the suit to manifold sizes herd and the introduction of water tankers increased subsidies livestock involving changes economic report The precipitation. response to erratic climates with limited annual includes plants, animals, that and people sustainability” as a of rational “triangle sophisticated a a of maintenance long-term into the permitted has that knowledge centuries and practices many of set complex over evolved have nomadic regions semi-arid and that arid in stated systems grazing ICAEDA, by report A oe oe oe hr o te ol’ ln area, land world’s which the of third ecosystems, one over cover dryland because It occurs by variations. primarily climatic and caused activities human is It areas. sub-humid asthe dry and semi-arid, arid, in land desertification of degradation defines UNCDD The degradation Desertification andland de ta socio- that added 161
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi are extremely vulnerable to over-exploitation particular oil and gas surveys, on biodiversity. and inappropriate land use. Other factors Land degradation reduces natural vegetation cover, and affects productivity. According to a Hunting and trapping of large mammal species study conducted by ICARDA Arabian Peninsula has resulted in very low population levels of Regional Program, working in collaboration Panthera pardus ssp. nimr and Hemitragus with the National Agricultural Research jayakari. Over the last few decades, the UAE has Systems (NARS), and other institutions over lost most of its big fauna such as the Arabian 90% of the total area now suffers from some leopard, Mountain Gazelle, Arabian Tahr, sort of overgrazing, and 44% is severely or very Development for tourism and recreation is severely degraded. The loss of biodiversity threatening habitats in and around Jebel Hafit, likewise undermines the environmental health which is Abu Dhabi’s only mountainous area. of drylands and makes them more prone to Habitat degradation and destruction are almost further degradation. inevitably accompanied by threats to individual According to IIED (2008) the major threat plant and animal species. The risk is that habitats to dryland biodiversity is land degradation are degraded to such an extent that they no longer resulting from climate variability coupled provide the means of support to specific species. with human induced factors like urbanization Examples of species that have become extinct and overgrazing, it is upon this bio-physical in the wild in Abu Dhabi include the Arabian and socio-economic base that climate change leopard, the Arabian wolf and the striped hyena impacts will unfold. Andrea (2006) stated that (Drew & Tourenq, 2005). recently, land degradation in more arid regions Oil spills are a threat to the entire coastline of of the world such as the Arabian Peninsula this ecoregion. Large vehicles and trucks cause coupled with progressive population growth has damage to bird and turtle nesting sites. Off- become a serious concern. Andrea (2006) also road driving inland causes much damage to the stressed the potential impacts of deforestation vegetation, which is slow to recover due to the and other forms of land resource exploitation, in limited annual rainfall.
162 face of adverse conditions. As we look to assess to look we As conditions. adverse of face the in even well function can biodiversity high with ecosystem an whole, a as – forms other to is the ecosystem of susceptible to some type of damage, element but resilient or each outbreaks, flooding); or disease pathogen wildfires, as (such periods short or climate) in shifts as affected by disturbances over long periods (such biodiverse ecosystem is highly less likely a to collapse portfolio, or be well-balanced adversely a Like ecosystem. an in change instability catastrophic ecological or promote may key and unfilled, leave niches biodiversity in Losses and isabletoresistchange. disturbance, and damage to resilient highly is same space. An ecosystem with high biodiversity different the in interact fauna many and flora of types distinct how its of is metric health a ecosystem biodiversity, of element key balances. One chemical or physical to and alterations patterns, climate in shifts pollution, use and function, as land such and influences human including structure ecosystem may which change drivers of range wide a are There 8. and climatechange ecosystem thresholds, Biodiversity, ht pplto i nt ag eog t re- to enough large not is population meaning a that populations, breeding in shortages biodiversity lossto: 2003). Researchers have attributed much of this of geologic historic mass extinctions (Balmford, 1997), rates extinction the Hughes, exceeding) not (if rivaling 2002; Erlich, and (Ceballose biodiversity of loss extraordinary an seen have centuries two last the speaking, that agree Generally researchers biodiversity. on change climate and (human) anthropogenic of role the but function, ecosystem on biodiversity of role It is important then, to understand not only the remain akeyconcept. will function ecosystem and biodiversity UAE, the on change climate of impact potential the overgrazing, orpollution);and habitat destruction(e.g. deforestation, climate change. species (e.g. overfishingandhunting); over-harvesting ofbothpredatorandprey Over-harvesting of species can lead to critical 163
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi populate itself, and imbalances in the food-web, restricts the ability for species to migrate or meaning that there is either not enough food for expand. Thus, even if total habitat space is top predators or there are too few predators to large, but is subdivided into small fragments, control the population of prey species. In these the net effect results in small, non-diverse (and circumstances, the imbalances can quickly often functionally deficient) ecosystems. stack up synergistically in a positive feedback Finally, climate change may already be cycle: for example, as top predators dwindle, responsible for some species losses and prey species multiply quickly and begin to threatens to lead to rampant reductions in deplete food sources for other species or change biodiversity globally. Climate change shifts the the physical or chemical properties of their basic substrates upon which ecosystems rely: ecosystem. For example, overfishing of Codfish as temperatures increase and precipitation in the rich kelp (seaweed) forests of the Gulf of patterns are altered, ecosystems which used to Maine allowed sea urchins to prosper, which in thrive in one region may be displaced to other turn destroyed the kelp habitat (Jackson et al, areas or disappear altogether. For many biomes 2001). Cod is now extinct in the North Atlantic, around the world, this shift may look like a mass and the habitat has, for all intensive purposes, movement of ecosystems towards the poles or changed permanently. higher elevations, while ecosystems already Habitat destruction results in the loss of near the poles or at high elevation may be lost ecosystem area or an impedance in ecosystem completely. function, and is, by far, the most pressing threat While the story is both complicated and to biodiversity worldwide. Pollution and habitat uncertain, it is likely that many sedentary misuse can destroy or impede key elements of or non-migrating species will be unable to an ecosystem, lending to severe imbalances and move at the pace of climate change, and even loss of ecosystem functionality. For example, migratory species may find their migratory overgrazing in arid ecosystems commonly leads routes falling out of synchrony with weather to the trampling of biogenic crusts and the loss and food patterns. For all of these reasons, it of critical vegetation cover, which, in turn, leads is likely that climate change alone will lead to to increased runoff and erosion, nutrient losses, significant biodiversity losses (Salaet al., 2000), and can promote invasive species. and the effect will be compounded where there The direct loss of habitat by land use change can are already significant environmental stresses, also result in the loss of biodiversity as parts of such as those described previously (Thomas et an ecosystem are transformed for another use, al, 2004). there is less area for the native ecosystem to use. The relationship between species diversity 8.1. Biodiversity and ecological and area has been recognized since at least thresholds the early 20th century, and was formalized by Williams (1964) and, later, Rosenzsweig (1995) In 2000, Sala and others predicted that as a logarithmic curve. In numerous studies, as “Mediterranean climate and grassland larger areas are examined, the number of species ecosystems likely will experience the greatest increases (i.e. from a small plot to a continent). proportional change [loss] in biodiversity” Geographical constraints, the ability to move, by 2100 due to the combined influence of migrate, and compete, and the ability to climate change, land use change, changes in escape small-scale disturbances all govern the atmospheric CO , and introduced (invasive) relationship between area and speciation. 2 species. Except for far northern and southern Within a specific type of biome or ecosystem, as latitudes, where climate change is expected to the physical size of the ecosystem is reduced, have the most significant impacts, changes in the number of species which can be supported land use are expected to be responsible for the in the ecosystem is also reduced. Expansion heaviest toll on biodiversity. According to the of urban areas, deforestation, sedimentation, Sala et al. (2000) analysis, if we assume that and agricultural expansion are all mechanisms interactions amongst the drivers of biodiversity of direct habitat destruction. Fragmentation change are synergistic and multiplicative,
164 Climate Change Impacts, Vulnerability & Adaptation sentation, Source Schefferetal.,2001. Figure 8-1:Themultiplestateecosystemrepre- , 06. h IC 4 IPCC The 2006). al., et (Groffman, ecosystem” small the in produce responses larger driver where environmental an or in changes phenomenon, quality, or ecosystem an property in change as “abrupt defined an been has threshold ecological An the UAE. in importance particular of be could threshold type. functional induced disturbance or climate a of theory The different completely ecosystem an a shift into and threshold, or point, tipping critical a reach could change of driver single a that feasible is Secondly,it above. the particular of drivers, or a synergistic combination of many of combination driver a powerful many, most amongst the only by may shifted biodiversity be and change understood biodiversity poorly of are interactions drivers of the nature amongst the First, Sala assertion. the to caveats important two are There change. small relatively a hot see to analysis, expected are in this deserts used definitions the By factors. change of array wide the to due losses severe most the to exposed be may ecosystems savanna and grassland, Mediterranean, then th seset report Assessment 165
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi considers that “there may be critical thresholds of maximum ecosystem stability, with two areas beyond which some systems may not be able to of “attraction” (labeled as F1 and F2). adapt to changing climate conditions without Along the solid line, as conditions change radically altering their functional state and smoothly, the state of the ecosystem changes system integrity” (IPCC, 2007). Practically smoothly. However, a significant perturbation speaking, defining the criteria to reach a in either the state or the ambient conditions threshold is very difficult to determine: either may be enough to push the ecosystem into it requires empirical evidence from similar a new steady state. This shift could be both systems which have undergone some threshold perceived and labeled as a catastrophic change. change, or a nearly flawless mechanistic model In this representation, the depth of the wells (a potentially unachievable gold standard). is a measure of the ecosystem’s resistance The theory of whether distinct, quantifiable to change (its intrinsic stability at particular thresholds exist in complicated, natural conditions), while the steepness of the well ecosystems continues to be debated in the walls represents the resilience of the ecosystem literature (Burkett et al., 2005; Briske et (given a disturbance, how likely is the ecosystem al., 2006; Groffman et al., 2006), but there is to return to its initial state). general agreement that the concept is at least illustrative, if not functionally applicable in many In this case, resilience can be envisioned as the circumstances. To be susceptible to threshold magnitude of a disturbance required to push the behavior, an ecosystem must have the potential ecosystem into a new steady state (Carpenter et to obtain multiple stable states. Ecosystems al., 2001). In the context of climate change and of all sizes are always in a state of flux, with biodiversity, climate change would be a shift various components continually recovering in ambient conditions, driving the ecosystem from disturbances; therefore, ecosystems do through a smooth transition along a steady- not simply obtain a ‘climax’, but may reach a state line. However, if land use change, habitat stable equilibrium, in which the functional state destruction, or pollution weakens resilience, it of the system remains essentially the same may be trivial to push an ecosystem into a new despite disturbances. Some have described steady state. the steady state as a suite of positive and A threshold could be crossed by stressing negative feedback loops, which balance to keep multiple state variables, or even a single ecosystem function relatively constant (van de important state variable such as climate change Koppel et al., 1997). or precipitation availability. Changes in critical In some cases, either extreme disturbances loadings, such as nutrients, temperature, or or (more often) chronic disturbances may be water availability can trigger a catastrophic enough to either enhance a positive feedback change, and external anthropogenic forcing can cycle or attenuate a negative feedback cycle, and also push a threshold envelope. the state of the ecosystem shifts dramatically. The concept of a threshold is a useful concept, The shift from one stable state to the next yet may lack a specific application in real world requires that the system be pushed past a management. Ecosystem models have been built particular threshold before settling into a new to explore the nature of ecosystem equilbria, and steady state (Scheffer et al., 2001). in these process-based models, it is relatively Current ecosystem theory suggests that multiple trivial to simulate threshold behavior. Since steady states can be envisioned in a three even process-based models inevitably rely on dimensional space (see Figure 8. 1) representing some degree of empirical numerical estimations, the ecosystem state and conditions on a flat thresholds are, to some degree, built into these plane, and a measure of ecosystem stability in models. However, in practice, it is difficult to the vertical plane (Scheffer et al., 2001). The define the boundaries of a natural ecosystem “ecosystem state” is simply the functional form state and the contributing conditions such of an ecosystem under a certain set of conditions. that a threshold can be quantitatively defined. The conditions may include climate, chemical, To define a threshold effectively, either the and physical properties of the area. The line behavior has to have been observed already in represented on the flat plane traces the region a similar ecotype, or the understanding of the
166 Climate Change Impacts, Vulnerability & Adaptation Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi system across multiple spatial scales has to be or disappear: Similarly to desert margin so comprehensive that it is reasonably certain a ecosystems, both natural and managed threshold exists (Scheffer, 2001). ecosystems in Wadis and on mountains are at risk as temperatures rise and precipitation It is worth noting that in the literature, although patterns change. In many parts of the world, ecosystems are described as having multiple species which survive on the mountains of steady states in almost all circumstances the alternative state is one of severe degradation arid regions persist because the mountains relative to the original condition. So, for receive either marginally more precipitation, example, while a lake ecosystem can either or have slightly cooler temperatures than persist as a clear water system with a diverse lowlands. These so-called “sky-islands” are range of invertebrates, benthic life, and fish, or able to support a higher diversity of both as a eutrophic, nutrient overloaded pool with plant and animal species, and many will be heavy algal cover, clearly the original condition threatened by changes in climate. As global is preferred for biodiversity, function, and temperatures increase, the only available environmental quality. climatically acceptable area for these species will be at higher elevations, which almost 8.2. Implications of climate change always have less area available; if temperatures on UAE dryland ecosystems increase as dramatically as expected in some scenarios, many of these ecosystems will be displaced altogether (i.e. made locally extinct; The implications of climate change for the arid ecosystems of the UAE are several fold, Halpin, 1994). In seasonally moist wadis, a and we explore several case examples in the similar balance could be threatened by more next section. However, we can potentially intermittent runoff. Plants which require state several widely applicable principles for continual soil moisture could be exposed to ecosystem changes in hot, arid regions. extended droughts, and experience elevated rates of erosion as heavy precipitation floods Increases in aridity and reductions in these ecosystems. soil moisture: In general, if precipitation remains low but both daytime and Drylands shift towards invasive annuals or evening temperatures increase in the shrubby perennials: Dryland ecosystems UAE, we would expect that soil moisture are highly responsive to the frequency and will decline significantly. The amount of magnitude of rain pulses (Xu et al., 2004; moisture available to plants is a function Huxman et al., 2004; Sponseller, 2007). At the of precipitation, infiltration into soils, and smallest of precipitation pulses, infiltration evapotranspiration, or the amount of water may not extend more than several millimeters which evaporates from surfaces or is released into the soil, and can stimulate photosynthetic by the stomata of plants. As temperatures activity in biological soil crusts (an important increase, evapotranspiration rises, and micro-ecosystem of fungi, bacteria, and algae soil moisture declines (Xu et al., 2004). If discussed in more depth later) while remaining precipitation events are more severe yet less ineffective in triggering growth in vascular frequent, we would expect more water to run plants. Annual grasses with dormant seed off soil surfaces and thus remain unavailable bank may germinate with heavy early-season to plants. precipitation, while the growth of perennial shrubs can be enhanced by sufficient mid- Narrower margin of semi-arid grasslands season rainfall (Huxman et al., 2004). Shallow- and scrublands: The shift towards more rooting grasses are able to take advantage arid soils will render it increasingly difficult of short mid-season rain pulses as small for even highly drought-adapted plants to as 5 mm (Sala and Lauenroth, 1982), while survive along desert margins. In the African deeply rooted perennial shrubs rely on low- Sahara, extended drought periods (decade- lying water reserves and larger precipitation length, or longer), regularly extend sandy events, but are able to withstand extended desert margins into previously productive droughts. Once established, grasslands landscapes (ref). can become dominant through repeated Mountaintop and wadi ecosystems reduced brushfires, which destroy perennial shrubs.
168 Climate Change Impacts, Vulnerability & Adaptation os snhoy ipcig oh oa and migratory species. local both impacting synchrony, loose in UAE,will dependent precipitation highly the particularly biota, interdependent that species some in (Visser fallen population have correspondingly, abundances and breed not do earlier, insects these on feed which birds migratory However, well. as advanced correspondingly has growth vegetation early the annual abundance 2000), of insects warmer which Reiter,rely on and to (Schwartz due temperatures hemisphere northern the throughout advanced has spring of date the co-dependent biota (Morisette between these synchrony disrupt that critical may patterns concern seasonal in significant changes is there precipitation in researchers, phenological changes Amongst patterns. to adapt plants elastic as periods growth spring delayed or earlier either of in form the in shifts materialize may be will throughout shifts these UAE, biomes the In cycles. phenological of change range wide climate a of impacts expected the of One heat. summer intense of and near or complete senescence by the onset growth, of period the following immediately flowers or seeds distributing plants periods, intense short, see bursts of growth to during winter or spring rainy uncommon not is stress. It heat avoid and availability water of cycles are timed to take maximum advantage phenological plants, desert many For heat. excessive and availability water seasonal on dependent be often temperatures, can patterns biotic cool but or availability restricted light are biota by that rare is it tropics, arid the In water. and temperature, availability light, of resource seasonal governed by are primarily phenology) called (all fauna of migration and hibernation, offlora foraging, and in fruiting patterns and flowering, growth, Annual the phenology: in Shifts the semi-ariddrylandsofUAE. in shrubs or grasses of dominance the shift to expect may we rainstorms), intensity high (evenly areas. regime distributed low rainfall intensity rainfall concentrated or infrequent the on small Depending in resources available using water resources, and effectively pool nutrient by dominance ecosystem retain shrublands established Alternatively, ., 1998). There is a significant risk significant a is There 1998). al., et et al., 2008). For example, as change Avian migrationandphenological for biodiversityintheUnitedArabEmirates. implications its and change, ecosystem of type threshold- follow,a for potential the explore we extensively more which studies case four the been of each In studied. have which similar other biomes from lessons heed and change, ecosystem vulnerabilities in dryland the UAE explore that pertain to can climate we However, to climatechangealoneintheUAE. due consequences environmental potential of unlikely that we can make a definitive assessment intensity and timing as an ecological driver, it is rainfall of importance the Given 2006b). (UAE, 2100 by more 22% to less 45% as wide as gap a and 2050 by more 10% to less 20% from predict Models 2007). IPCC, (see particular UAEin the and general, in Peninsula Saudi the in change precipitation volumes and patterns with climate There are significant uncertainties in predicting 8.3. cvnes bzad ad aes, predators ravens), and (buzzards scavengers larks), as (such insectivores are species avian the Amongst birds. are Emirate Dhabi Abu the Nearly 81% of listed higher vertebrate species in thresholds intheUAE induced biodiversity Examples ofclimatechange 169
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi stopover sites is critical for migrant’s survival. The reproductive success of a migratory birds depends on critical habitat being available at the right time of year, a condition which could quickly be undermined with climatic change.
The phenology1 of migratory birds is closely linked to the phenology of the sites these birds visit for winter feeding, summer breeding, and interseason passage. For some species, migration appears to be triggered by the state of vegetation at the site they are at (as the vegetation or forage quality declines, the birds depart), while for other species, migration is closely linked to a precise time of year. As the climate changes, there is a distinct risk (already seen in some well-studied species) that bird populations will increasingly migrate asynchronously with their food sources, arriving either well before or after and raptors (owls, eagles, and falcons), and a peak available forage. For example, the Great Tit wide variety of herbivorous and wading water (Parus major) in the UK forages on caterpillars birds (ducks, plovers and terns). About 70% during its breeding period; however, caterpillar (271) of the avian species are land based birds, abundance follows the arrival of spring and has while the 30% (117) are water-based. Over 80% advanced by nearly 15 days over two decades as of the land birds, and 90% of the water birds are spring temperatures in the northern hemisphere migratory. rise. This migratory species breeds according to a photoperiod (daylength) signal, and appears Migrants in the Central Asian Flyway migrate to now be temporally mismatched, putting the from the UAE towards northern Central Asia in population at significant risk (Visser et al., 1998). the spring, breed, and return to the UAE as a winter feeding ground (Central Asian Flyway, There is not necessarily a clear or predictable 2005). Long-distance migrants in the East pattern to help determine if migrant species African / West Asian Flyway are funneled over will be impacted by these timing changes. For the Arabian Gulf and through the UAE as they example, Walther and colleagues (2002) found pass from African wintering grounds to Asian that short-distance migrants tended to trend and European breeding grounds. For wading towards earlier arrivals with changing climate, water birds, the many lagoons, mud flats, khors while late-arriving long-distance migrants and mangrove stands found along the Persian either did not change arrival times or even Gulf and the Gulf of Oman provide ideal feeding delayed them. These phenological shifts may sites. create a significant mismatch between peak It is known that forage quality in wintering forage availability and food demands. A more grounds is a critical predictor of survivorship recent analysis attempted to generalize the for migratory bird species. In poor conditions, impacts of climate change on multiple types female birds are slow to depart for northern of bird species, both migratory and resident; breeding grounds, and may not have enough Sekercioglu and others (2004) suggest that energy to make the journey or arrive soon under a business-as-usual climate change and enough to breed and reproduce successfully land use practice scenario “by 2100, we expect (Marra et al., 1998). Less well studied, but 6-14% of all historic bird species to be extinct, equally important, the quality of forage at 7-25% to be functionally extinct, and 13-52% to
1Phenology: seasonal biotic patterns which follow abiotic phenomena
170 Climate Change Impacts, Vulnerability & Adaptation Sakkir (2004) note that the arid lowland interior unique (Drew support fauna endemic turn in which ecologies, and plants soil of variety a flats. support by dunes salt These Sabkha interrupted tracts and plains dunes, gravel large of and strips sheets by sand dominated of Arab United are the of Emirates regions inland low The savanna ecosystems grasses, invasives,anddesertin Transitions betweenshrubs, natural and dryland ecosystems). mudflats, mangroves, (coastal forage reduced reductions as well as both availability with cope to Species have shift. may climates as loosing stopover sources for food and risk their at overwintering particularly are UAE, migrants the In and more extinctionsthanaverage.” have piscivores, to predicted are Specialists scavengers. nectarivores, frugivores, to herbivores, rates extinction than-average greater- project We deficient. functionally be , 03. rw and Brown 2003). al., et in forage area forage in coastal belt and the desert interior can widely can interior desert the and belt coastal Sudanian the between differentiation zonal the UAE, the In use. land availabilit y,and nutrient temperature), and light (precipitation availability, climate particular soil of substrate influences and joint a the of by governed is ecoregion an in community dominance the Generally, climatic attributable coastal broadly Sudanian differentiations. be may the belt within subtle more boundaries even boundaries and zones, The these 2004). between Sakkir, and (Brown Amaranthaceae) (Asteraceae, perennials annuals and flowering and (Cyperaceae), (Fabaceaesedges ), legumes Gramineae), (Poaceae, Prosopis cineraria or “Ghaf”) numerous grasses richer (i.e. trees significantly some including flora, a has belt Sudanian The Calligonum). Astragalus, Silene, Spergularia, (i.e. herbs (i.e. and annuals flowering vegetated, shrubs and Ononis) legumous sparsely some is but region Arabian semi-arid interior. The hyper-arid Arabian Sudanian) an and (or savanna, Nubo-Sindian belt of coastal narrow a zones: biogeographical overlapping two considered be can UAE the of Acacia tortilis, Acacia Medicago, 171
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi be defined climatically (Boer, 1997), although senesce and dormancy. However, extended increasingly harsh land use practices along droughts can begin to reduce the ability of even the coast may rapidly overtake contemporary the most drought tolerant grasses to survive climate as an ecosystem driver. In undisturbed with no rainfall. Some arid systems (such as soil savannas, the frequency and intensity of biota) have been shown to display a heartiness rainfall and temperature fluctuations drive the threshold, failing to thrive when temperatures distribution of grasses, trees and shrublands. increase without a concurrent increase in Land uses and disturbances add a level of precipitation (respiration increases with complexity to the story: Grazing dynamics temperature and a negative carbon balance (both intensity and timing) can quickly shift leads to senescence; Xu et al., 2004). Recent can force semi-arid grasslands towards either observations show that the Sahara desert was shrub or grassy monocultures; fire frequency previously a wooded savanna ecosystem, which alters the balance of shrubs and grasslands; dried out significantly about 4,300 years ago, and human disturbances, such as road building and then lost all vegetation cover approximately and mineral extraction, commonly introduce 2,700 years ago (Claussen et al., 1999; Kröpelin exotic and invasive species. In the UAE, some et al., 2008). exotics have been introduced for horticultural purposes (such as Prosopis juliflora, an acacia) Increasing aridity, when coupled with intensive and are spreading invasively (Essa et al., 2006). land use, is particularly damaging. In arid regions, herbivores play an important role in To date, the most significant threats to the maintaining biodiversity and providing nutrients dryland ecosystems of the UAE have been from to soils, but in wet years, both native herbivores land use and development practices: camel and livestock can increase dramatically, leading overgrazing of sensitive vegetation (Gallacher to overgrazing in following years (Holmgren, and Hill, 2008), rapid urban development (Brown 2006). The Millennium Ecosystem Assessment et al., 2004), and unchecked groundwater on Desertification (MEA, 2005) suggests that extraction (Zoebisch and DePauw, 2004; Brook transitions from low to high pressure grazing et al., 2005). However, changes in the already force a rapid transition from grasslands to extreme climatic conditions of the UAE could shrublands, with a subsequent increase in significantly impact the already strained erosion, loss of biodiversity, productivity, and ecosystem. The semi-arid Sudanian coastal ecosystem services, such as groundwater belt could see rainfall reductions, or shifts in recharge. A potential climate-change induced intensity and timing, which could lead to shifts threshold then may be induced by either in the dominance of grasses, shrubs, and trees, a changing balance of temperature and or even a loss of biota altogether. precipitation, or relatively small changes in Many researchers (Ogle and Reynolds, 2004; climate coupled with increasing land use and van de Koppel et al, 2004; Holmgren, 2006) grazing pressures in the UAE. have found that in desert ecosystems, plant functional types respond to precipitation pulses 8.4. Adaptation to climate change differently: relatively small amounts of rainfall in drylands trigger growth and respiration in biological soil crusts at the top several centimeters of soil, The IPCC defines climate change adaptation while less common, but larger precipitation as: 'Adjustment in natural or human systems in events trigger the growth of grasses and response to actual or expected climatic stimuli or sedges. These grasses survive drought years by their effects, which moderates harm or exploits producing large seed stores in rainy years which beneficial opportunities'. An alternative definition then sprout in future rainy years. is offered in the inter-agency report, Poverty and Finally, rare heavy rainfall events can migrate Climate Change, as The ability to respond and through soils into groundwater and contribute adjust to actual or potential impacts of changing to the growth of trees and shrubs with deep climate conditions in ways that moderate harm taproots. These shrubs survive drought through or take advantage of any positive opportunities that the climate may afford.
172 Climate Change Impacts, Vulnerability & Adaptation the relativelyreliablerainfall. on depend also plants perennial the of Some rain. winter the of advantage takes that cycle life a to adjusted having annuals, winter be to UAEappear the in 80 species plant all of Some cent per rain. next the until dormant lie will this time they’ll have to produce new seeds that their life cycles last only a few weeks and during Subsequently, these plants develop quickly and material and releasethemonlyafterrain. plant older with seeds their protect Some rain. sufficient after only germinate and drought of periods long survive to able are that short very period of time. a Some plants in produce seeds cycle life their complete and rapidly develop to leaves. ability the succulent has species plant in Other water the storing often source, this of use make plants some and year often water that only will reach ground the level are for is most of the dew areas, flowers some In and inconspicuous numerous, more are andprickles spines and hairs leafless, appear plants some trees, tall fewer There countries. temperate in plants from appearance different totally a have could UAE the in species Plant temperatures andlowrainfall. high levels, salt high to adaptations interesting plant 450-500 of between show Many species. introduced and range indigenous number may UAE the in species (1989), Western to According conditions. arid the survive to ways interesting developed have plants many desert, burning (Medina fire and desiccation from cells insulate to living bark corky or nutrient and water store to systems ground e.g.below large having species land dry for characters certain has induced example, for drylands rainfall, resilient the of characterizing pattern most erratic and seasonal the The among conditions. climatic are unfavorable to ecosystems Dryland Autonomous adaptation both cover change. will section autonomous and planned adaptation to climate This important. particularly is climate in changes to responses efforts individual these Understanding (autonomous). self-directed occur can through it or spontaneously planned be can Adaptation , 92 SST, 99. n the In 1999). SBSTTA, 1992; al., et different plantorgansareasfollows: by adaptation for Examples temperature, high to exposure the minimize and resources water scarce and of use make adaptation to designed specifically in are the play to role of soil a have parts plants Different especially adaptations. individual controlling species in habitat, vital are conditions local Generally in feedinghabits. camels and hares tend to be largely nocturnal by day. Hence many herbivore species such as be can than night by volume of terms in more much but varies water stored of The amount loss. water prevent to an layer with wax outer covered are some they Moreover, summers. dry long, during used be can that sap contain globular, are halophytes, which or leaves bear species, Salt-tolerant e.g. leaves to reduce others evapo-transpirations, like needle small, very their develop many of leaves- modification the is plants dryland Leaves: bear spinesorprickles may and tough and hard usually is shoot the root long shoot, pattern – mostly in the ratio of 1: 6. Moreover, short a by characterized always are plants dryland The system: Shoot than shootstoreachoutforwater. roots longer have plants Young dactylifera. palm date the and cinerea Prosopis as such species local of true as such is This systems. perennials root deep have usually trees Woody system: Root tmt coe uig a tm ad pn by open and time day during close stomata the where plants desert some in observed adaptation is unique very A Photosynthesis: flowers. attractively-coloured large bear which of both mountains, the in and sands the in species are Exceptions year. of time that at agents insect suitable of because lack relative a of wind-pollinated be to likely more plants are orautumn Desert summer the in pollination. flower which o indicates method flowers of the colour The Flowers: its evaporation. dense with prevent and water the trap to spines or hairs covered be may Stems Some give much support against the blowing winds. which jointed much are stems Some Stems: n motn aatto i the in adaptation important An species Capparis Acacia tortilis, Acacia Tribulus Phoenix 173
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi night when gas interchanges take place, and Insitu conservation of species has also been water is used much more efficiently. The planned in the Emirates. Based on Al-Abed and absorbed carbon dioxide is temporarily stored Hellyer (2001), adaptation efforts in shrubland overnight and then transfused through the and woodland areas, could be focused on the plant during the day while the stomata are restoration and rehabilitation of impacted closed. This phenomenon occurs in several ecosystems. Currently only two protected areas, common UAE species including Portulaca one terrestrial, Al Wathba Wetland Reserve, and oleracea, Aizoon canariehse and Citrullus the second marine reserves, Morrawah Marine colocynthis. Protected area, have been formally established through official decrees. Al Wathba, an inland Autonomous adaptation by Fauna wetland with an area of 4.9 km² was declared as protected area mainly to protect the breeding Desert ecosystem is home to a wide range colony of the Greater Flamingo Phoenicopterus of animals which are biologically adapted to roseus, while the Morrawah Marine protected extremely harsh climatic conditions and survive Areas (MMPA) covers 8 islands and intervening for long periods of time with little or no water. waters covering an area of 4255 km² and has Most of the desert animals have autonomously been established to protect overall marine developed adaptive strategies to their dry biodiversity including birds. environment by e.g. “burrowing or spending long Two more protected areas, the Jebel Hafit periods resting in holes well below the surface, National Park with a proposed area of about while others move rapidly beneath the surface 96 km² and Umm az-Zamul National Park of uncompacted sand. Some possess hard or with an area of more than 10000 km² have thorny skins. The camel is a typical animal been proposed. To provide protection for which is the most adapted mammal to the resident and migratory species of land birds desert conditions. With all his organs modified such as Egyptian Vulture, Sand Partridge, to store and efficiently utilize the water. Hoopoe Lark and the Golden Eagle (Aquila Planned Adaptation Strategies chrysaetos) and Eagle Owl. The proposed protected areas are expected to provide Although ecosystems have adapted to changing protection mainly from human interference conditions in the past, current changes and disturbance. However, more research and are occurring at rates not seen historically, studies are needed to identify the impacts of consequently, coping with future climate change climate change on different plant and animal will require effective adaptation in dryland species as well as their natural habitat, and to areas. Throughout the UAE, significant effort develop the appropriate adaptation measures. has been expended toward afforestation and the IUCN (2006) identified a number of measures construction of green areas. Such green tracts that need to be implemented to increase the while conserving tree species, they provide adaptation of mangroves to impacts of climate shade and evaporative cooling effects, as well change including: restore degraded areas that as some degree of protection from sandstorms have demonstrated resistance or resilience for cities in the UAE (Salloum, 2001). to climate change; understand and preserve connectivity between mangroves and sources Adaptation efforts could include the expansion of freshwater, establish baseline data and of these afforestation programs, with a monitor the response of mangroves to climate significant focus on the more efficient use of change and to implement adaptive strategies to water for tree and plant production. While compensate for changes in species ranges and green areas provide an invaluable service environmental conditions. According to IPCC- to dryland ecosystems and protection of TAR, identifying peripheral species of interest the inhabited areas which they border, it is and protecting their habit will likely enhance important to manage their development in a planned adaptation for natural ecosystems. manner integrated with water resources to avoid competition between different uses.
174 Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi 9. Modeling climate spatial and time scales, from photosynthetic reactions in individual leaf cells, to patterns change impacts in the of water distribution and disturbance across a landscape, to complex feedback cycles between UAE vegetation and the atmosphere. 9.1 Ecosystem models: limited While there have been great insights at every understanding, limitless level of study over recent decades, models still simplify processes by necessity, assuming possibilities relationships or causations when possible and not critical to the model outcome. The end Much of our understanding of ecosystem result is that ecologists developing or applying structure and function today is derived from ecosystem models usually start a modeling ecosystem models, driven by a variety of data process by determining which fundamental types, from remote sensing to field observations sets of relationships can be fixed, and which to physical first principles, and operating at a need to be variables (and how these variables wide range of complexities and scales, from will be portrayed). Therefore, it has been nearly global vegetation and climate coupled models impossible, to date, to develop models which to empirical observations of time series or are both general and accurate across biomes. processes at a single field site. Models have However, this is not to say that models have not provided some of the best insights into how yielded great steps forward in understanding climate change might be expected to impact ecosystem function and process. ecosystem structure and function. A reasonably good rule of thumb for applying There is no single clear definition for an ecosystem models is that these systems should “ecosystem model”, as most are designed with be used for exploring patterns and dynamics in a specific questions in mind. For example, coupled biome or region, but should not be counted on to climate-ecosystem models arose from the need provide predictive capacity in most situations. A to more accurately portray generic vegetation model can help a scientist discern critical factors characteristics (such as evapotranspiration, driving ecosystem change such as climate, land albedo, and surface roughness) in global and use, or disturbance (Veldkamp and Lambin, regional climate models (Hurtt et al., 1998), 2001), or assist a land manager in determining an while empirically-based field models are used to appropriate timing or intensity of fire or grazing explore explicit relationships such as the impact (Anderies et al., 2002). Increasingly, models of changing groundwater or agricultural regimes are being used to explore potential impacts of on vegetation cover (Elmore et al., 2003; Elmore climate change, ecosystem vulnerabilities, and et al., 2006), the effect of seasonal temperature the developing field of “adaptive management”, variations on vegetation phenology (Schaber managing and modeling iteratively to achieve and Badeck, 2003; Fisher et al., 2007), or the an ecosystem goal. Below, we describe some impact of rainfall frequency and abundance of the fundamental bounds and constructs of on carbon flux (Weltzin et al., 2003; Sponseller, ecosystem models, and explore specific case 2007). examples in arid ecosystems. There are fundamental differences between models developed from field-based empirical Empirical or first principles? Top- data and those that attempt to work at larger down versus bottom-up models regional or global scales. It is important to note even before our discussion of model potentials Ecosystem models encompass a wide universe and fundamentals that ecosystem models are of possible model constructs, yet there are intrinsically limited by both available data, some useful first order classifications which computational complexity, and in general by our can serve to clarify the philosophy behind the imperfect knowledge of ecosystem processes. model, and how the model is ultimately used The study of ecology asks biologists to explore and interpreted. One of the most important and understand data across a vast range of classifying mechanisms is whether a model
176 Climate Change Impacts, Vulnerability & Adaptation each arebrieflydescribedbelow. of aspects Key assumptions. and scope, scale, by limited severely are models ecosystem All Model limitations biomes. future impact may disturbance and use, land change, climate how explore to used being now respiration, and nutrient requirements), and are biomes from first principles (i.e. photosynthesis, major of function and able structure the predict are to models these of versions developed most the of Some today. exist not may which ecosystem simulated a on conditions impose and dynamics, understand factors, forcing and components ecosystem between relationships explore to is models these of point structured The today. are way ecosystems the and by limited communities or observers) fallible by such possible, that they are not as constrained by data (collected general are as be to models built often mechanistic These the at micro-scale. operate ecosystem an of components approach relies on established theories on how individual modeling bottom-up the Broadly, directly ondata. importantly,based most are and, assumptions, their in explicit highly often are interpret, and construct to simple relatively be can they that is models empirically-based of advantages The relationships, which may then be statistical used for predictive purposes. compile to datasets dense use may or data; satellite or series time long as such information, spatial or temporal rich with datasets simplifying model, or interpreting of CASA methods be may the models Empirical below). (see conditions climate changing predicts under vegetation which of patterns system spatial a complex or as variables, be of can set a through relationship a describe to function a deriving as simple as be when using empirical data. Empirical models can blurred is model more a and construct experimental an are between line down the because only top if common, the from built Models empirical observations(top-down). of understanding theoretical system dynamics (bottom-up) or if it is built on a on based is n csse ocr t ir-cls where micro-scales, at occur ecosystem an in processes fundamental most The Scale: vlaig h ipcs f lmt cag on ecosystems andbiodiversityintheUAE. change climate of of impacts range the evaluating wide for useful be may a types several but functions, span models Ecosystem 9.2 Types ofecosystemmodels rcse and processes simplify mechanisms withempiricalrelationships. models most entirely the rigorous even rarely level, some at are mechanistic: models First-principles (bottom-up) mechanisms. or pathways discrete model rarely and replicable, least at or causal, are variables relationships correlated between that assume often example, for models, Empirical assumptions. general of list developed well a have) should (or has Assumptions: Every form of ecosystem model processes operateacrossscales. are simulated many and limited, data and computationally are processes to these levels which The availability). light region (climate, the and (competition), community the (disturbances), patch the availability), water and light mortality, (individual stem the herbivory), shading, senescence, growth, example, (for leaf the of scale the at happen occur, are, however, also important processes which respiration nutrients and are utilized, and water is cycled. photosynthesis There photosynthetic pathway (C pathway photosynthetic and deciduous), or (evergreen longevity leaf needle-leaf), or (broadleaf form leaf grass), or (tree physiognomy between distinguish which types functional plant simple to down types plant reduce often scope in global are types plant functional which Models species. individual than rather to down detail of level the reduce to has often one model, the in biomes diverse more yet include then to individual characteristics; of known with species number floristic modest a or model simulate to choose might one effectively, must assumptions biome of type single a its simulate To become. general more be, the to strives model a broader The Scope: irrelevant for studies at the sub-biome scale. irrelevant forstudiesatthesub-biome or ineffective be may dynamics global-scale et al., 2004). Models which effectively capture 3 or C or 4 ) (i.e. Wang(i.e. ) 177
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi First principles ecosystem difficult to apply at small scales and lack the models: potential vegetation and ability to discriminate changes in composition disturbance more detailed than basic functional types. In addition, mechanistic models can only describe Mechanistic models are designed to simulate a limited degree of complexity, and may neglect the structure, function, and (sometimes) detailed, yet critical, interactions (such as dynamics of ecosystems based on a “first nutrient or water flow between clustered principles” understanding of the components shrubs and grasses in a semi-arid system, or of the ecosystem. Exclusively, these models different phenological responses to seasonality simulate and follow changes in vegetation and drought). composition only, and do not consider fauna, This class of model may be useful in determining except occasionally as numerical agents of climate impacts on the UAE if the predominant disturbance. The bottom-up approach is an question is in regard to biomass, ecosystem effective way of exploring how a biome forms, feedback cycles, or how an ecosystem might be and which climatic and competitive features structured in the UAE without an anthropogenic drive the equilibrium composition of a biome. influence. There are no standard structures for mechanistic models, but many do share common features. Bioclimatic envelope models The mechanistic component is usually a Bioclimatic envelope models are designed to set of equations describing carbon balance explore how species ranges may shift in response (photosynthesis and respiration) with available to climate change. It has long been understood light and water for a small variety of plant that climate (precipitation and temperature) functional types (i.e. grasses, shrubs, trees, strongly controls the ability of certain species and deciduous and coniferous species). Various and functional types to survive and thrive levels of sophistication in these models may (Pearson and Dawson, 2003), and in fact, one describe important ecosystem components, of the central tenants of biogeographical niche depending on the question at hand: theory is that an ecological niche can be defined by the environmental variables which affect a Water availability and transfer: water species. Major biomes, and even biogeographical infiltration into the soil and uptake by roots boundaries within these biomes, are largely (CARLUC, Hirsch et al., 2004) defined climatically. Individual species may have Physical structures: tall trees deprive shorter a narrow range of acceptable climates, or an shrubs and grasses of light (ED, Moorcroft et envelope in which they are typically found (the al., 2001) “realized niche”) or should be found based on known biological functions (the “fundamental Disturbances: fires, windstorms, and other niche”). Bioclimatic modeling asserts that we destructive events (IBIS, Foley et al., 1998; can anticipate the ecosystem impact of climate ED) change on species ranges (at the regional scale) Nutrient dynamics: available nitrogen in by determining the new bounds on bioclimatic soils, roots, stems, and leaves (TEM, Tian et envelopes. al., 1998) Bioclimate envelope modeling suffers from Seasonality: changes in leaf density, at least three shortcomings (see Pearson and senescence (CASA, Potter et al., 2004) Dawson, 2003):
These mechanistic models are useful for Competition: how a species might thrive in understanding how large scale changes in an environment and how it actually interacts climate or other abiotic factors will change in its community can be very different; if a biome locations or biomass, or tracing complex species is non-competitive within its climate envelope, it may not be found in the new feedback mechanisms (such as how shifts in environment. vegetation abundance impact climate patterns, Wang et al., 2004). These models, however, are Adaptation: it may be more effective for a
178 Climate Change Impacts, Vulnerability & Adaptation ehnsi mdl dsrbd bv, these non and based above, theoretically usually are models described models mechanistic the to Similarly ecosystem? the of composition and function the impact scale) landscape a at (usually ecosystem an of structure spatial the does how questions: have similar answer but to evolved lineages, distinct two least at have Patch structure and spatial distribution models distribution models Patch structureandspatial sensing datatorunsuccessfully. significant models require These biodiversity. or ranges species underlying question is in regard to expected new the if UAE the in change climate of impact the This class of model may be useful in determining potential speciesrange. are the determine rules to variables new derived the to applied the and scenario, change assumptions. climate a for derived envelope are variables climate New climate the validate to used is data remaining The 2003). Dawson, (Pearsonstandard and a is 70% and data the of presence or absence are determined on species a subset discriminate best which statistical ranges) their networks, clustering, or decision trees), the variables (and (neural mechanisms and drought lengths. rainfall, Using a variety of of classification frequency time-period, a over precipitation of volume threshold, temperature a over days of number period, critical a during temperatures minimum or maximum warming period, or time- cooling a over temperature average days, degree include may variables Climate locations. all for derived are variables climate and presence-absence), (as range wide physical locations of a species is recorded over a underlying methodology (Araujo an share models bioclimate Empirically-based a b al t epot uh oe f their fundamental climaterange. of more much exploit to able be may highly while generations, new to disperse many of course the over even or zones, climatic migrate to unable be may species non-mobile dispersal: Species new a in establish and physical location. migrate to it for than climate changing a to adapt to species field and possibly remote possibly and field oie species mobile et al., 2005): the tmeaue peiiain ad available timing and the to year) the of times key at sunlight precipitation, factors of climate (temperature, Many various fauna. relate models and these flora of seasonality empirically of drivers usually the understand to model, strive which based, of class unique and distinct a are models Climate-phenology Climate /phenologymodels camels, onaridecosystemhealth. by primarily impacts, grazing and composition, precipitation frequency and intensity influence on ecosystem both evaluating of in UAE context the the in change climate of impact the This class of model may be useful in determining 1999) Weber2001; al., et Adler 2004; Rietkerk, and Koppel de van (i.e. landscapes vegetated sparsely of composition or health, structure, the changes and disturbance herbivory how determine to simulations fire or grazing distribution with combined be Spatial may models available. are nutrients of pools where or plants, between transferred is water water how plants, much individual to available how is determine may grasses limiting of critical are factors. The distance availability between shrubs or clumps water and nutrient where ecosystems semi-arid or arid in applied seen often are models Such important. systems proximity,is physicalheight, are which than rather in systems dynamic the models explore to developed distribution Spatial certain environments. in vegetation new with in replaced are (treefalls) questions gaps quickly Important how around revolve models these 2004). Mailly, and (Busing width stem as such metrics, tracked simply more from height tree and size, branch density, leaf estimate to equations allometric using stand, the in tree each of cover leaf and trees, and often explicitly model the shape, size, of stands individual for environment water and light the simulate models These rainforests). to as (such environments developed light-limited dense, in models, trees of height stand and growth of rate the estimate forest derived are from models gap, or structure, Patch vegetation, ratherthanfauna. of dynamics the track usually and site-specific, 1998; Aguiar and Sala, and Aguiar 1998; al., et 179
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi of leaf development, fruiting, and senescence, or less often, the timing of migration or breeding success for various fauna. In light and temperature limited ecosystems (such as temperate and arctic forests), these models use long time series or large spatial datasets to derive a series of climate forcing factors which appear to trigger changes in phenology (see Schwartz, 1998 and Zhang et al., 2003, respectively). These models may be structured similarly to the bioclimatic models described previously, but rather than tracking the spatial presence or absence of a particular species, they track the timing of specific phenological phenomena.
This class of model is widely applied in ecosys- tems where a gradient of climatic phenomena creates a gradient of ecosystem response (such as in temperate forests in relation to tempera- Figure 9-1. The adaptive management cycle ture). However, climate-phenology models may prove to be highly important in determining Source Frankin et al., 2007. the impact of climate change in the UAE when examining potential asynchrony between sym- of B. tectorum destroy most native shrubs biotic species (i.e. if insects which feed on de- and singe the surface of the soil, inhibiting the veloping plants are unavailable as a food source growth of other species. It is not uncommon to migrating birds at the time when the birds to see large tracts of B. tectorum monoculture require it, the bird population could be put at throughout the Great Basin. risk; Beaumont et al., 2006). Bradley and Wilcove (2008) explored the 9.3 Examples of applied ecosystem dynamics of B. tectorum in a bioclimatic models in arid environments model. Tracts of cheatgrass were identified using a remote sensing technique, and climatic Modeling for climate change information was pulled together from a high impact assessment resolution climate dataset (4.5 km resolution). The researchers used an automated mechanism The arid Great Basin in the southwest United to determine the smallest set of explanatory States supports extensive perennial grasslands climate variables, which ultimately included and shrubs, and for decades has provided a rich average precipitation from June to September grazing resource for cattle ranchers throughout (summer to senescence), annual average the country. In the mid-1800’s, Cheatgrass precipitation, precipitation from April to (Bromus tectorum) was accidentally introduced May (spring), and average temperature from from Asia. B. tectorum is an invasive species December to February (winter). Using a climate in the Great Basin, and the annual is highly model (GFDL2.1) with a CO2 doubling scenario adapted to semi-arid to arid environments. The (720 ppm by 2100, SRESA1B), the researchers grass is not palatable to livestock and is able determined how the climate variables would to compete effectively with both native grasses change by 2100 and determined if and where B. and shrubs. It grows earlier than native grasses, tectorum would occur in the future climate. The depriving them of nutrients, water, and light. In researchers determined that cheatgrass would rainy years, B. tectorum can quickly grow several become less viable in 50% of its current area, feet in height, after which it is extremely fire but might invade specific new areas north of its prone. Raging brush fires through large tracts current range. As a result, the team suggested
180 Climate Change Impacts, Vulnerability & Adaptation cnevto ga i st sc a the as such set, is goal First, conservation 4). Figure a (see steps iterative several comprises program management adaptive An the Western US(seeabovefordetails). its and in tectorum Bromus program controlling to application management adaptive an creating of process the describes (2007) al., et The Franklin tool. benchmarking a and management goal. as explicitly the modeling techniques incorporates achieve system to management necessary where adjusting regular a for on basis, met are technique goals ecosystems and benchmarks a managing goals and to checking that ensure conservation is iteratively of management Adaptive management Modeling foradaptive drought thanwouldotherwisebeexpected. Sahel African may have the brought in about a losses more persistent vegetation and use land droughts may Sahel, be less severe. However, the intensive in naturally persist to allowed was vegetation if that found multi-decadal results The of droughts. severity the enhance Sahel found that seasonal vegetation dynamics in the researchers the model, GENESIS-IBIS the of version improved an using where, (2006) al. et Wangby explored further was observation This and precipitation more denser vegetation. subsequently and temperatures, cooler to lead would peninsula vegetation Arabian the and Sahel increasing African the throughout that the indicated error, in model Although atmosphere. the vegetation cycling and between by loops own feedback its through on equilibrium to a come to create would attempt which model ecosystem first comprehensive a 1998). was al., effort et This (Foley variability climatic and model cover vegetation between dynamics explore (IBIS) to transport model ecosystem an atmospheric and (GENESIS) rigorous a between coupling successful a demonstrated In 1998, a team from the University of Wisconsin vulnerabilities Modeling tounderstand reduce the invasionprobability. to soon begin steps remediation that opeesvl udrtnig n then and for understanding approaches promising comprehensively most the of One 9.4 in thepark. results are guiding fire management procedures model The outcomes. vegetation change might fires different how estimate to model Scales) Vegetation Patterns and Processes at (Simulating Landscape SIMPPLLE the employed project (Romme tectorum B. invasion by of rate the enhance or might inhibit either patterns fire changing how control explore modeling to used Verde) to (Mesa southwest arid program the in Park National US federal major a in cheatgrass a Similarly, use todeterminetheefficacyoftreatment. managers tested for biodiversity, the planting bird density, and habitat region, each and In grasses. native grazing, herbicides, burning, applying including various the techniques, test management to areas experimental into reserve prairie a of portions small designated this In several “treatments” to control cheatgrass, and tectorum. developed organization B. non-profit a program, control States to United western designed in Wyoming the of in state program management adaptive an of Frankin next the iteration ofthemanagementplan. craft to used results is the and plan tested management hypothesized vetted, a which in experiment, natural a as management the use to is process management adaptive the of goal The iterated. is process entire model, the and next the into incorporated is process hypotheses. New information learned from the management and goals benchmarked against implemented, and results are regularly checked management plan. The management plan is the then in posed hypotheses test independently to of the model, and a monitoring plan a is developed Third, management management plan is developed processes. from the results occurring both naturally of and components critical specific ecosystem is created which incorporates the or specific system. Secondly, species, a detailed model rare of the a preservation of a certain type of biodiversity in of a establishment or preservation of a specific species or community, data collectionintheUAE Next stepsformodelingand (07 dsrbs cs study case a describes (2007) al. et , 06. The 2006). al., et 181
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi managing for climate change impacts in zoned areas, agricultural regions, reserves the United Arab Emirates is to employ the and parks. data collection, assessment, management, and monitoring techniques of the adaptive Development of essential management framework (see Franklin et al., environmental studies 2007). While not directing a specific course of action, the framework asks for concerned From this initial literature survey, it is unclear stakeholders to first and foremost identify the what, if any, threat climate change poses to the goal of both ecosystem study and management, dryland ecosystems of the United Arab Emirates. and create a monitoring and assessment system It is apparent that land use practices, invasive such that both current and future managers species, intensive grazing, and groundwater can learn from both successes and inevitable extraction may pose a more immediate danger, failures as the goal is pursued. but the relative magnitudes of these natural and anthropogenic disturbances are unclear. The Development of baseline datasets UAE would benefit from a significant investment in basic ecosystem and climate studies to better In nearly every circumstance, unless the only understand the various components of change goal of ecosystem management is to create in the region. Potential studies could include: an aesthetically pleasing environment, it is critical to lay a foundation of data and basic Expected climate change in the biomes of the environmental science in the region. To date, UAE at a fine spatial scale as well as model there are few enviromental studies available and data uncertainties; regarding the UAE’s ecosystems, which means that there is little substrate to develop Which factors determine biogeographical well informed management practices. State boundaries in the UAE; agencies have compiled diversity surveys, but The impact of grazing pressures on there are few comprehensive sources describing groundwater, soil moisture, and ecosystem such fundamentals as biogeography, species structure; abundance, or biodiversity hotspots. Basic informative and widely accessible datasets Expected land use changes and urban would ideally include: development over the next decades, and Species or community maps of ecosystems the effect of various land use practices on throughout the UAE and surrounding regions, landscape health, biodiversity, and species in a georeferenced digital form; abundance;
Biogeographical surveys describing dominant How vegetation responds to interannual biomes in the UAE and their basic structures, variability in the UAE’s climate; functions, and vulnerabilities; How migratory species respond to interannual Climatic maps and datasets, indicating variability in the UAE’s climate; patterns of precipitation and seasonal The UAE sits at a the confluence of three temperatures; distinctly different ecoregions. With floral and Soils and groundwater assessments to map faunal influences from Africa, East Asia, and surface features and plant-available moisture the Middle East, the UAE and the Arabian and groundwater; peninsula harbor a unique biodiversity and critical habitats. There is a potential to Topographic maps; understand this relatively poorly characterized Important migratory routes; landscape, to learn about what may be in store for arid regions of the world. Land use maps indicating urban and urban-
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Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi 186 Annex 1: Global vulnerable area
Note that the vulnerable areas are mostly in mid-latitudes near 30 degrees of latitude. Climate ChangeImpacts,Vulnerability &Adaptation Annex 2: Expected effects of global warming on Asia
Glacier melt in the Himalayas is projected developing countries of Asia as it to increase flooding, rock avalanches compounds the pressures on natural from destabilised slopes, and affect resources and the environment water resources within the next two to associated with rapid urbanizations, three decades. This will be followed by industrialisation, and economic decreased river flows as the glaciers development. recede. It is projected that crop yields could Freshwater availability in Central, South, increase up to 20% in East and Southeast East and Southeast Asia particularly in Asia while it could decrease up to 30% in large river basins is projected to decrease Central and South Asia by the mid-21st due to climate change which, along century. Taken together and considering with population growth and increasing the influence of rapid population growth demand arising from higher standards of and urbanization, the risk of hunger is living, could adversely affect more than a projected to remain very high in several billion people by the 2050s. developing countries.
Coastal areas, especially heavily- Endemic morbidity and mortality due to populated mega-delta regions in South, diarrhoeal disease primarily associated East and Southeast Asia, will be at with floods and droughts are expected greatest risk due to increased flooding to rise in East, South and Southeast Asia from the sea and in some mega-deltas due to projected changes in hydrological cycle associated with global warming. flooding from the rivers. Increases in coastal water temperature Climate change is projected to impinge would exacerbate the abundance and/or on sustainable development of most toxicity of cholera in South Asia. 187
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi 188
Annex 3: Main urban settlements in dryland areas Climate ChangeImpacts,Vulnerability &Adaptation Annex 4: Main drivers of ecosystem change 189
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi Annex 5: List of regular wintering and breeding water birds in the United 190 Arab Emirates
Sn Species Scientific name Family Status Remarks
1 Little Grebe Tachybaptus ruficollis Podicipedidae Breeder Resident breeding species 2 Great Crested Grebe Podiceps cristatus Podicipedidae Migrant Rare Migrant 3 Black-necked Grebe Podiceps nigricollis Podicipedidae Migrant Winter Migrant, Occasional breeder 4 Wilson>s Storm Petrel Oceanites oceanicus Hydrobatidae Migrant Summer & Winter visitor 5 Red-billed Tropicbird Phaethon aethereus Phaethontidae Breeder Localised breeder; post-breeding dispersal 6 Socotra Cormorant Phalacrocorax nigrogularis Phalcrocoracidae Breeder Post breeding dispersal 7 Great Cormorant Phalacrocorax carbo Phalcrocoracidae Migrant Common winter migrant 8 Night Heron Nycticorax nycticorax Ardeidae Migrant Passage / winter migrant; occasional breeding 9 Striated Heron Butorides striatus Ardeidae Breeder Resident 10 Western Reef Heron Egretta gularis Ardeidae Breeder A common resident breeding species
Climate ChangeImpacts,Vulnerability &Adaptation 11 Little Bittern Ixobrychus minutus Ardeidae Migrant Regular migrant 12 Bittern Botaurus stellaris Ardeidae Migrant Uncommon winter migrant 13 Squacco Heron Ardeola ralloides Ardeidae Migrant Regular passage migrant 14 Indian Pond Heron Ardeola grayii Ardeidae Migrant Regular non-breeding migrant 15 Cattle Egret Bubulcus ibis Ardeidae Migrant Common winter migrant 16 Little Egret Egretta garzetta Ardeidae Migrant Common passage migrant 17 Great Egret Egretta alba Ardeidae Migrant Uncommon passage migrant 18 Grey Heron Ardea cinerea Ardeidae Migrant Common winter migrant 19 Purple Heron Ardea purpurea Ardeidae Migrant Common passage migrant 20 White Stork Ciconia ciconia Ciconiidae Migrant Uncommon passage migrant 21 Glossy Ibis Plegadis falcinellus Threskiornithidae Migrant Uncommon passage migrant 22 Spoonbill Platalea leucorodia Threskiornithidae Migrant Winter migrant 23 Greater Flamingo Phoenicopterus ruber Phoenicopteridae Migrant Passaga and winter migrant with some resident birds 24 Mallard Anas platyrhynchos Anatidae Migrant Common winter migrant 25 Greylag Goose Anser anser Anatidae Migrant Uncommon winter migrant 26 Ruddy Shelduck Tadorna ferruginea Anatidae Migrant Uncommon winter migrant 27 Shelduck Tadorna tadorna Anatidae Migrant Winter migrant, localised Sn Species Scientific name Family Status Remarks
28 Wigeon Anas penelope Anatidae Migrant Regular winter migrant 29 Gadwall Anas strepera Anatidae Migrant Uncommon winter migrant 30 Teal Anas crecca Anatidae Migrant Common winter migrant 31 Pintail Anas acuta Anatidae Migrant Common winter migrant 32 Garganey Anas querquedula Anatidae Migrant Common passage migrant 33 Shoveler Anas clypeata Anatidae Migrant Common winter migrant 34 Pochard Aythya ferina Anatidae Migrant Localised winter migrant 35 Ferruginous Duck Aythya nyroca Anatidae Migrant Scarce winter migrant 36 Tufted Duck Aythya fuligula Anatidae Migrant Uncommon 37 Moorhen Gallinula chloropus Rallidae Migrant Migrant with some resident breeding birds 38 Spotted Crake Porzana porzana Rallidae Migrant Regular passage migrant 39 Little Crake Porzana parva Rallidae Migrant Rare passage migrant 40 Baillon>s Crake Porzana pusilla Rallidae Migrant Rare passage migrant 41 Corn Crake Crex crex Rallidae Migrant Rare passage migrant 42 White-breasted Waterhen Amuarornis phoenicurus Rallidae Migrant Rare winter migrant 43 Purple Gallinule Porphyrio porphyrio Rallidae Migrant Rare winter migrant 44 Coot Fulica atra Rallidae Migrant Localised winter migrant 45 Red-knobbed Coot Fulica cristata Rallidae Migrant Rare winter migrant 46 Water Rail Rallus aquaticus Rallidae Migrant Scarce winter migrant 47 Black winged Stilt Himantopus himantopus Recurvirostridae Breeder Common resident, some local movement 48 Avocet Recurvirostra avosetta Recurvirostridae Migrant Irregular migrant with some breeding birds 49 Oystercatcher Haematopus ostralegus Haematopodidae Migrant Common winter migrant 50 Crab Plover Dromas ardeola Dromadidae Breeder Resident, post breeding dispersal and winter influx 51 Collared Pratincole Glareola pratincola Glareolidae Migrant Regular autumn migrant 52 Oriental Pratincole Glareola maldivarum Glareolidae Migrant Rare autumn migrant 53 Red-wattled Lapwing Vanellus indicus Charadriidae Breeder; Migrant and some breeding regularly 54 Kentish Plover Charadrius alexandrinus Charadriidae Breeder Common resident; winter migrant 55 White-tailed Plover Vanellus leucurus Charadriidae Migrant Regular winter migrant; occasional breeder 56 Little Ringed Plover Charadrius dubius Charadriidae Breeder Passage migrant; breeding summer migrant
191 57 Ringed Plover Charadrius hiaticula Charadriidae Migrant Common migrant 58 Lesser Sand Plover Charadrius mongolus Charadriidae Migrant Common winter migrant
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi Sn Species Scientific name Family Status Remarks 192
59 Greater Sand Plover Charadrius leschenaultii Charadriidae Migrant Common winter migrant 60 Caspian Plover Charadrius asiaticus Charadriidae Migrant Uncommon passage migrant 61 Dotterel Eudromias morinellus Charadriidae Migrant Rare autumn migrant 62 Pacific Golden Plover Pluvialis fulva Charadriidae Migrant Regular winter migrant 63 Grey Plover Pluvialis squatarola Charadriidae Migrant Common winter migrant 64 Lapwing Vanellus vanellus Charadriidae Migrant Rare winter migrant 65 Great Knot Calidris tenuirostris Scolopacidae Migrant Winter migrant 66 Sanderling Calidris alba Scolopacidae Migrant Common winter migrant 67 Little Stint Calidris minuta Scolopacidae Migrant Common winter migrant 68 Temminck>s Stint Calidris temminckii Scolopacidae Migrant Regular winter migrant 69 Long toed Stint Calidris subminuta Scolopacidae Migrant Rare passage migrant 70 Curlew Sandpiper Calidris ferruginea Scolopacidae Migrant Common winter migrant 71 Dunlin Calidris alpina Scolopacidae Migrant Common winter migrant
Climate ChangeImpacts,Vulnerability &Adaptation 72 Broad-billed Sandpiper Limicola falcinellus Scolopacidae Migrant Regular winter migrant 73 Ruff Philomachus pugnax Scolopacidae Migrant Common winter migrant 74 Jack Snipe Lymnocryptes minimus Scolopacidae Migrant Rare 75 Snipe Gallinago gallinago Scolopacidae Migrant Common winter migrant 76 Great Snipe Gallinago media Scolopacidae Migrant Rare passage migrant 77 Pintail Snipe Gallinago stenura Scolopacidae Migrant Localised winter migrant 78 Black-tailed Godwit Limosa limosa Scolopacidae Migrant Localised winter migrant 79 Bar-tailed Godwit Limosa lapponica Scolopacidae Migrant Common winter migrant 80 Whimbrel Numenius phaeopus Scolopacidae Migrant Common winter migrant 81 Curlew Numenius arquata Scolopacidae Migrant Common winter migrant 82 Spotted Redshank Tringa erythropus Scolopacidae Migrant Scarce winter migrant 83 Redshank Tringa totanus Scolopacidae Migrant Common winter migrant 84 Marsh Sandpiper Tringa stagnatilis Scolopacidae Migrant Uncommon winter migrant 85 Greenshank Tringa nebularia Scolopacidae Migrant Common winter migrant 86 Green Sandpiper Tringa ochropus Scolopacidae Migrant Common winter migrant 87 Wood Sandpiper Tringa glareola Scolopacidae Migrant Common winter migrant 88 Terek Sandpiper Tringa cinerea Scolopacidae Migrant Common winter migrant Sn Species Scientific name Family Status Remarks
89 Common Sandpiper Tringa hypoleucos Scolopacidae Migrant Common winter migrant 90 Turnstone Arenaria interpres Scolopacidae Migrant Common winter migrant 91 Red-necked Phalarope Phalaropus lobatus Scolopacidae Migrant Common winter migrant 92 Grey Phalarope Phalaropus fulicarius Scolopacidae Migrant Scarce winter migrant 93 Sooty Gull Larus hemprichii Laridae Breeder Common 94 Pomarine Skua Stercorarius pomarinus Stercorariidae Migrant Common passage migrant 95 Arctic Skua Stercorarius parasiticus Stercorariidae Migrant Uncommon passage migrant 96 Great Black-headed Gull Larus ichthyaetus Laridae Migrant Uncommon winter migrant 97 Black-headed Gull Larus ridibundus Laridae Migrant Common winter migrant 98 Brown-headed Gull Larus brunnicephalus Laridae Migrant Uncommon winter migrant 99 Slender-billed Gull Larus genei Laridae Migrant Common winter migrant 100 Common Gull Larus canus Laridae Migrant Rare winter migrant Lesser Black-backed (Baltic) 101 Larus fuscus Laridae Migrant Uncommon winter migrant Gull 102 Siberian Gull Larus heuglini Laridae Migrant Common passage migrant 103 Caspian Gull Larus cachinnans Laridae Migrant Common winter migrant 104 Lesser Crested Tern Sterna bengalensis Sternidae Breeder Summer breeding visitor 105 Caspian Tern Sterna caspia Sternidae Breeder winter migrant; passage migrant; some breed in country 106 Swift (Crested) Tern Sterna bergii Sternidae Breeder Migrant breeder 107 White-cheeked Tern Sterna repressa Sternidae Breeder Migrant breeder 108 Bridled Tern Sterna anaethetus Sternidae Breeder Migrant breeder 109 Saunders> Little Tern Sterna saundersi Sternidae Breeder Migrant breeder 110 Gull-billed Tern Gelochelidon nilotica Sternidae Migrant Common passage & winter migrant 111 Sandwich Tern Sterna sandvicensis Sternidae Migrant Common winter migrant 112 Roseate tern Sterna dougallii Sternidae Migrant Uncommon winter migrant 113 Common Tern Sterna hirundo Sternidae Migrant Common winter migrant 114 Sooty Tern Sterna fuscata Sternidae Migrant Uncommon winter migrant 115 Little Tern Sterna albifrons Sternidae Migrant Regular summer migrant 116 Whiskered Tern Chlidonias hybridus Sternidae Migrant Common passage migrant
193 117 White-winged Black Tern Chlidonias leucopterus Sternidae Migrant Regular autumn migrant
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi Annex 6: Important flora 194 of the UAE
Sources:
adapted from M.V.D. Jongbloed, G.R. Feulner, B. Bِer, A.R. Western, 2004. A comprehensive Guide to Wild Flowers of UAE Gulf of Oman desert and semi-desert (AT1306), 2008- Peer review in process
Name of species/sub-species Habitat/location of species Status/condition
Endangered on the IUCN Red List (IUCN 2001); population numbers around 200,000 individuals, Socotra cormorant (Phalacrocorax nigrogularis) Endemic to Arabia peninsula representing 15-33% of the estimated world population (Aspinall 1995). Climate ChangeImpacts,Vulnerability &Adaptation
Zygophyllum qatarense and Salsola imbricata as dominant species, with Heliotropium kotschyi, sandy coastal strip with tidal lagoons Fagonia ovalifolia, Suaeda vermiculata and Panicum turgidum mixed in.
mangrove - Avicennia marina - Arthrocnemum macrostachyum dominates the tideline, - various saltbushes such as Halopeplis perfoliata, Suaeda spp., Anabasis Near Abu Dhabi in many inshore islands Setifera And Salsola imbricata. Cornulaca monacantha, Heliotropium kotschyi and Convolvulus deserti .
-Halopyrum mucronatum grass Further north in the low dunes along the seashore -Salsola imbricata. Name of species/sub-species Habitat/location of species Status/condition
mixed stands of Cornulaca monacantha and Further inland Atriplex leucoclada higher ground Crotalaria persica and Sphaerocoma aucheri Haloxylon salicornicum with Cornulaca monacantha, Cyperus conglomeratus, in low dunes with deep water table Zygophyllum madavillei and Haloxylon salicornicum and grasses such as: Setaria verticillata, Stipagrostis plumosa and Centropodium forskahlii. annuals Cleome amblyocarpa, Eremobium wet springs aegyptiacum and Silene villosa
Rhazya stricta and Haloxylon salicornicum East of Al Ain the gravel plain Fagonia ovalifolia, Indigofera argentea - Astragalus spp In fenced areas -Cleome amblyocarpa
Acacia tortilis and On gravel plains further north around Haloxylon salicornicum Dominate Madam and Dhaid Rhazya stricta
Capparis sinaica and . The limestone hills of Jebel Faiya and Jebel Dominates Ochradenus arabica, Mileiha
Tephrosia purpurea Mountain Dominates and Salvadore persica stands. foothills to the east
Prosopis cineraria forest and annuals such as the west of Digdaga and Khatt on the Malva parviflora, Sisymbrium and Geranium Dominates fertile Jiri plain spp.
Euphorbia larica and Tephrosia The Hajar Mountains Purpurea and bushes such as Gaillonia Dominant
The sand desert Cyperus conglomeratus and Calligonum comosum In the west mobile dunes Tribulus omanense grows along with a sparse Zygophyllum
195 sandy plains between the dunes qatarense and Halopeplis perfoliata a Heliotropium digynum and Limeum arabicum In deep sands
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi 196
Annex 7: Recorded mammalian taxa occurring in UAE
Order Families Extinct Introduced Total Number Species of Species Species
Carnivora 5 3 3 14
Climate ChangeImpacts,Vulnerability &Adaptation Perissodactyla 1 1 1
Artiodactyla 1 3 2 8
Rodentia 3 1 3 11
Hyracoidea 1 1 1
Lagomorpha 1 1 Species inBoldareclassified asextinctinthewild Annex 8: Arabian Jird Sundevall's Jird Cheesman's gerbil Baluchistan Gerbil Wagner's Gerbil Egypian SpinyMouse Lesser Jerboa Indian Porcupine Rodentia Cape Hare Lagomorpha Sand Gazelle Mountain Gazelle Arabian Oryx Wild Goat Nubian Ibex Arabian Tahr Artidactyla Arabian Leopard Caracal Sand Cat Gordon's Wildcat Striped Hyaena Mongoose White-tailed Honey BadgerorRatel Blandford's Fox Rüppell's Fox Red Fox* Wolf Carnivora BAt Hemprich's Long-eared Kuhl's Pipistrelle Sind SerotineBat Persian Leaf-nosed Bat Trident Leaf-nosed Bat Naked BelliedTomb Bat Bat Muscat Mouse-tailed Egyptian FruitBat Chiroptera Savi's PygmyShrew Brandt's Hedgehog Ethiopian Hedgehog Insectivora Common Name mammals ofUAE Native specieslistofterrestrial Meriones arimalius Meriones crassus Gerbillus cheesmani Gerbillus nanus Gerbillus dasyurus Acomys cahirinus Jaculus jaculus Hystrix indica Lepus capensis Gazella subguttarusamarica Gazella gazellacora Oryx leucoryx Capra aegagrus Capra ibexnubiana Hemitragus jayakari Panthera pardusnimr Caracal caracal Felis margarita Felis silvestrisgordoni Hyaena hyaena Ichneumia albicauda Mellivora capensis Vulpes cana Vulpes rueppelli Vulpes vulpes Canis lupusarabs Otonycteris hemprichii Pipistrellus kuhlii Eptesicus nasutus Triaenops persicus Asellia tridens Taphozous nudiventris Rhinopma muscatellum Rousettus aegyptiacus Suncus etruscus Hemiechinus hypomelas Hemiechinus aethiopicus Scientific Name 197
Impacts, Vulnerability & Adaptation for Dryland Ecosystems in Abu Dhabi
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