Zurich Open Repository and Archive University of Zurich Main Library Strickhofstrasse 39 CH-8057 Zurich www.zora.uzh.ch Year: 2019 State of the knowledge on water resources and natural hazards under climate change in Central Asia and South Caucasus Muccione, Veruska ; Fiddes, Joel Posted at the Zurich Open Repository and Archive, University of Zurich ZORA URL: https://doi.org/10.5167/uzh-181441 Published Research Report Published Version Originally published at: Muccione, Veruska; Fiddes, Joel (2019). State of the knowledge on water resources and natural hazards under climate change in Central Asia and South Caucasus. Bern: Swiss Agency for Development and Cooperation. Thematic Input Paper 1 State of the knowledge on water resources and natural hazards under climate change in Central Asia and South Caucasus Authors: Veruska Muccione (University of Zurich, Switzerland), Joel Fiddes (University of Oslo, Norway and Swiss Institute for Snow and Avalanche Research SLF, Switzerland) 1. Background/Scope perspective. We synthesise knowledge from peer review literature and to a certain extent key literature of interna- Climate change is expected to have profound impacts on tional organisations. We have used available datasets to water resources and natural hazards in Central Asia and generate new graphs on climate and glacier changes in South Caucasus. It is critical that we understand such im- the region. The reviewed literature is necessarily biased pacts, particularly in the context of rapid socio-econom- towards Central Asia due to considerably less literature ic change that will have implications for the vulnerability being available for the South Caucasus region. of populations in the region. This paper aims to provide a synthesis of the scientific evidence of these changes, their magnitudes and expected consequences. These two distinct regions have extremely heterogeneous climates 2. Regional profiles controlled by elevation and latitude and by location on the Central Asia consists of the former Soviet republics of continent. Given the large spatial extent of the regions, lo- Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uz- cal climates are highly variable. bekistan. Central Asia covers an area of 4 million square kilometres and has a population of 60 million people and The paper starts from an analysis of observed and project- a population density of just 15 people/km2. It has a varied ed changes in term of the atmospheric drivers of change, topography characterised by vast deserts, grassy steppes e.g. air temperature and precipitation anomalies at the and high, glaciated mountain ranges. Mountains cover global and regional level. Observed climate change re- approximately 20% of the area, with Tajikistan and Kyrgyz- fers to measurements taken at individual stations, satellite stan being the most mountainous countries (>90% of their data and data obtained from assimilated meteorological territories). Major mountain ranges are the Tien Shan and data (reanalysis data). Climate projections are obtained the Pamir-Alai. The Tien Shan mountain range spans from by using quantitative methods to simulate the response Uzbekistan to Kyrgyzstan, and in the south-east from Ka- of the main earth’s system components (air, land, oceans, zakhstan to China (Xinjiang). Major river systems of the re- cryosphere) to an increase in greenhouse gas (GHG) con- gion include the Amu Darya and the Syr Darya. Major water centrations. Climate scenarios to simulate future GHG con- bodies are the Aral Sea, Lake Balkhash and Issyk Kul Lake, centrations are given by the Representative Concentration which are part of the west-central Asia endorheic basin that Pathways (RCPs). In this paper we will refer to results for also includes the Caspian Sea (Figure 1). the RCP2.6 and RCP8.5 scenarios. RCP2.6 represents a mitigation scenario aiming at keeping the level of global The climate of the region is extremely heterogeneous and mean temperature increase to 2 °C above the pre-industri- strongly controlled by latitude, altitude and location on al level, whereas RCP8.5 represents a scenario of business the continent. Mean annual air temperatures (MAATs) are as usual with an expected average temperature increase around +5 °C in northern Kazakhstan to +20 °C in southern to 4 °C above the pre-industrial level. We then assess the Uzbekistan, whereas MAAT is strongly sub-zero in many state of knowledge on climate change impacts on water parts of the Tien Shan and Pamir (Figure 3A). Precipitation resources, weather extremes and mass movements. We is controlled by the same factors, with arid interior regions discuss implications of climate change for the manage- of Uzbekistan and Turkmenistan (200mm) whereas north- ment of water resources and natural hazards through a risk ern parts of Kazakhstan are more humid (600–700mm). Thematic Input Paper 1: State of the knowledge | 7 Aralsk Northern Lake Balkhash Aral Sea Ili delta 4 (38) 5 KAZAKHSTAN Eastern Ili Aral Sea CHN 4 Western Khorgos Aral Sea Aral Kum Desert KAZ 1.3 16 Ili basin 12 Chu-Talas basin Kapchagay Res. KAZ 2.2 Chu Almaty KAZ (other rivers) 1.5 Muynak KAZ 0.6 KAZ 10 Talas S yr 4.8 Da ry KYR 3.3 Karakalpakstan 7.9 a Taraz Bishkek Issyk-Kul 1.5 Akshirak Enilchek Sarygamysh Lake 1 Prospective Shymkent KYR 0.9 Tien-Shan Collector KYRGYZSTAN K a ra Aksu B Chirchik- Naryn o g Aral Sea basin a Aksu z Charvak G o Ahangaran l Tashauz 6.5 Tashkent 15 Horezm 4.4 UZBEKISTAN 9 UZB 10 KYR 3 (UZB) (37) Kara Darya Golden Age Lake Dashoguz Collector 4 CHINA (under construction) UZB 5.3 Aydar Lake TJK 2 Osh nt Lebap 3.9 1 Rivers of ka 2 Yar Ferghana Valley: 8 Kashgar Zar UZB 10 avs Kashgar Bukhara han TURKMENISTAN Samarkand KYR 0.1 5.3 Fedchenko Amu-Bukhara 5.2 Kafarnigan Central Asia Kashkadarya 0.3 Great Turkmen Collector 1.2 Vaksh Water resource formation and use Dushanbe TAJIKISTAN Surhandarya Pamir TJK 6.6 Average water withdrawal Ashgabat Karshi 4.2 UZB Panj High water losses along Sherabad 1.4 0.6 1.5 (km/year) Karakum Canal 1.5 Amu Darya Average ow 0.5 70 0.2 4.8 20 30 (km/year) rakash Atre 0.98 5.5 Ya Ka k Karakum Canal 11 rka 10 nt 5 M u 33 r g a Other rivers: 6.2 b Mountain regions above 2000 metres Kokcha T Mashad e j e Irrigated lands n ndus IRAN I Drainage water and irrigation run-o AFGHANISTAN Re-use of drainage PAKISTAN Kunduz Main glacier areas Srinagar Kabul River basin outline Hari Rud Country boundary 0 250 km Islamabad Map produced by Zoï Environment Network, June 2018 Source: water ow and water use data www.cawater-info.net Figure 1: Water Resources in Central Asia ab en s h u C d In Precipitation hotspots of up to 2,000mm can be found in tremely diverse varying with both longitude and altitude. the Tien Shan and Pamir mountains whereas regions to The Great Caucasus range protects the region from the the east of the main ranges and bordering China are more direct penetration of cold air masses from the north and arid (Figure 3A). strongly dictates the precipitation rates. Precipitation de- creases from west to east and generally mountain areas South Caucasus consists of the former Soviet states of receive more precipitation than low-lying areas. The re- Armenia, Azerbaijan and Georgia, and sits between the gion shows an extreme precipitation gradient west to east Black Sea (west) and Caspian Sea (east). The Caucasus with 2,393mm/year in Batumi (humid subtropical) and area of 186,100km2 is home to a population of 16 million 258mm/year in Baku (cold semi-arid), while mean annual people. The Caucasus Mountains are the divide between air temperatures are quite similar at 14.2 °C and 15.1 °C, Europe and Asia and greatly influence the climate of the respectively. The largest rivers are the Mtkvari, the Kura region. The region shows a marked topography within a and the Araks, with lengths of 1,564, 1,515 and 1,072 kilo- very narrow distance. The highest point is Mount Shkhara metres, respectively (Figure 2). at 5,201m, and the lowest point is -28m. The climate is ex- 8 | Managing disaster risks and water under climate change in Central Asia and Caucasus Figure 2: Hydrographic map of Caucasus Source: Shannon/Wikimedia Commons, http://www.glimpsefromtheglobe.com/topics/politics-and-governance/forecas- ting-water-wars-in-the-caucasus/ 3. State of knowledge 3.1. Observed climate change Mean annual air temperature has increased over the past elevations of the Tien Shan Mountains (Kriegel et al. 2013; century over most of the South Caucasus and Central Asia Mannig et al. 2013; Zhang et al. 2009). regions. The numbers of cold days and nights have de- creased and the numbers of warm days and nights have Precipitation trends, including extremes, are characterised increased across most of Asia since about 1950, and heat- by strong variability, with both increasing and decreasing wave frequency has increased since the middle of the 20th trends observed in different parts of the region. In southern century in large parts of Asia (Hijioka et al. 2014). Central Asia, a weak downward trend in mean precipitation was observed in recent decades, although with an increase In line with observed northern hemisphere warming, large in intense weather events (IPCC AR5, Figure 3B). In moun- trends (>2 °C per 50 years) in the second half of the 20th tain regions, precipitation increases have been detected century were observed in the northern Asian sector (Hi- (e.g., Braun et al. 2009; Glazyrin and Tadzhibaeva 2011). jioka et al. 2014). Most studies focusing on Central Asia mountain regions also document mean-annual (Hijio- Reanalysis data from the European Centre for Medi- ka et al.