ICZM with a Focus on Climate Change Rise in Development Countries
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ICZM with a focus on climate change rise in development countries Hernan Moreano: Vice-President of COASTMAN – Ecuador Foundation Introduction The low Guayas River basin (LGRB), located in the Southwest of Ecuador, is the most productive area of Ecuador. It is an important area for agriculture and aquaculture, which is the leading export products, together with oil. The contribution of this region to the GDP is 20 billion US$. Farming and aquaculture provide direct and indirect jobs to 3.2 million people on a total population of 12.1 million. The inhabitants of the basin live mostly concentrated at Guayaquil (3 millions), which is Ecuador’s major port and the economic capital. Besides agriculture, the area holds a mangrove ecosystem of 120.000 ha and estuarine water bodies of 5100 km 2. These are associated with the Guayas River and Estero Salado estuaries, connected with the Gulf of Guayaquil through the Jambeli and El Morro channels. The climate of Ecuador’s Coastal Zone is determined by the position of the Inter Tropical Convergence Zone (ITCZ), the offshore water masses distribution and climate variability events such as “El Niño” Southern Oscillation (ENSO). All of these are responsible for flooding on the river basin areas and for sea level rise within the estuaries. The last ENSO event of 1997 – 1998, for the period of 10 months, impacted Equatorial Pacific coast, in this occasion the damages were valued at US$ 2.6 billions in the entire coast. This is a rough estimate made by the Latin American and Caribbean Economic Commission (CEPAL, 1998). Climate Change (CC) is a risk for Ecuador coastal zones and especially for the LGRB. For this reason we study the problems generated by CC, a final review of it was made in 2006. Four Equatorial institutions carried out the study: “Instituto Oceanografico de la Armada “(INOCAR), in charge of sea level rise studies in estuaries, “Instituto Nacional de Pesca” (INP) who must focuses its work in impacts on mangrove ecosystem, biodiversity and the shrimp industry, “Instituto Nacional de Meteorologia e Hidrología” (INAMHI) that focuses the research on precipitation and assessment of the low basin hydrographic system and “Instituto de Planificacion Urbana y Regional” (IPUR) join to the Catholic University (UCSG) for social and economic impacts in the study area. 1 Problem definition ICZM Under an Integrated Resources Management vision, an environment study, and the related social and economic issues, as well as a vulnerability assessment study of the Low Guayas River basin affected by climate change was conducted. In this study precipitation, sea level rise and ENSO events were considered as a matter of Climate Variability (CV) and were monitored periodically. The goals of the study included To assess the possible impacts of climate change at the present and future situation of coastal resources and their consequences on economic and social matters. To identify possible attenuation measures and projects that could give way outs with such measures. To develop planning tools for Impact Assessment on long term changes of resources and their use. To contribute to establish the Ecuador Coastal Zone management institutional structure. To support Capacity building in Integrated Coastal Management. To contribute to improve Ecuador National Communications on CC. Approach 2 The vulnerability assessment study was carried out all these years using the seven steps as described in the Vulnerability Assessment of Coastal Areas to Sea Level Rise. Steps 1 through 4 were made by the project coordinator and the working groups of involved institutions. Additionally a series of workshops were organized to define the boundaries of the study area, the possible climate scenarios for precipitation and sea level rise, formulation of response strategies, results assessment and a long term structure proposal to manage the Low Guayas River Basin. A common methodology focused on natural and socio-economic system impact assessment, as a consequence of the physical effects of sea level rise and on the effects of response strategies was made. The vulnerability assessment began with a delineation of the study area and specifications of sea level rise, boundary conditions. Followed a study area inventory and the identification of relevant development factors related to productivity activities, capital investment and natural values were made. After completing these three initial steps, a physical change assessment and the natural system response were determined; this included morphological development of the shore line, water level and changes in salinity. Afterward, the response options were formulated, estimating their cost and effects, all this, considering scenarios that represent cases showing the cost of the response options in each economic scenario (with and without development). The vulnerability assessment ended assessing the susceptibility of changes, forced by sea level rise and related socio-economic impacts, followed by actions to develop a long term basin management plant, based on integration and participatory decision making. Results of the vulnerability assessment Guayas and Estero Salado estuaries were selected as study areas due to its sensitivity to sea level rise. Impacts of flooding already undergo on this area, could increase in the future as a result of sea level rise and changes in precipitation. The study area perimeter is 630 km and encircles an area of nearly 15.000 km2 that holds 200.000 ha of banana, rice and sugar cane farming fields. The zone has a population of 3.4 million people, mostly concentrated at Guayaquil, which is a city port, located at the upper branches of the Guayas River and Estero Salado estuaries where a series of islands and archipelagos are distributed nearby; most of them are covered by mangrove forest and shrimps ponds. On the southern part are located Machala and Puerto Bolivar, the main city and port, respectively. Estuarine waters are tide driven and their volume depends on ocean currents traits, mainly at the eastern Pacific, as well as on precipitation, fresh water river inputs, caused by the southward motion of the ITCZ, and by warm ocean water masses driven by surface currents or by the ENSO event. The geometry of these estuarine systems and the differences in phases with sea level make a complicated pattern of circulation, especially near the mouth area where both estuaries are connected. Through Guayas River estuary, salinity gradients are noticeable, since fresh water inflow fluctuates during the seasons. The maximum range of the salinity intrusion is as far as Guayaquil is located; but it does not penetrate further because of Daule River permanent flow, which is controlled by the Daule-Peripa Dam, in the north part. Vertical gradients are almost insignificant and 3 both estuaries fall in categories 1a and 1b, in the Hansen and Rattray (1996) circulation and stratification diagram. The tidal prisms for the Guayas and Estero Salado estuaries are 4.4 billions, and 1.2 billions cubic meters respectively. The flushing time for the Guayas Estuary is between 8 to 13 days and could be less in periods of high river flows associated with El Niño. In contrast, the Estero Salado upper part, located at the west of Guayaquil, does not have fresh water inflow and its flushing time is longer than this of Guayas. Going southward and close to the mouth, the water exchange with the ocean and with the other estuary increases, consequently the flushing time decreases. All three hydrographic systems are responsible for sediment transport and fresh water inflow into the study area. The economic situation The economy of Ecuador is marked by a huge external debt of US$ 13000 millions dollars, an annual budget with lack of resources to invest in productive sectors. The economy is characterized by a low foreign investment, lack of economical, legal and political systems guarantees. The economy manages high inflation and interest rates. At nowadays the country unemployment is about 10.3%. Two sectors are responsible for one third of exports incomes; they are the agriculture and shrimps farming, both of them taking place in the study area. The population has a growth rate near 2.2% per year. Climate Scenarios Several climate scenarios were established for 2010 Scenarios Conditions No changes in sea level, air and ocean surface temperatures and Basic (SLR 0) precipitation. Sea level rise 0.3 m, with an increase of 1°C in air temperature, Moderated Sea Surface temperature (SST) anomalies less than 1°C and a 15% (SLR 1) reduction in precipitation. Sea level rise of 1.0 m, with an increase of 2°C in air tem perature. Severe (SLR 2) SST anomalies over 2°C and a 20% increase in precipitation. As the study area is not affected by ocean storms, hurricanes and tornados, the climate scenarios do not consider data related to these events. Outputs of most Global Climate Models (GCM) are in Celsius degrees of air temperature variation and percentage of precipitation below or above average. Unfortunately, climate in the global context and particularly on Ecuador’s coastal zone is not only related to changes in the atmosphere, but also to changes in the offshore water masses driven by surface currents. These in turn are coupled to the wind driven circulation patterns on the Pacific Ocean. The proposed INAMHI scenarios were as follows (values for 2010 compared to 1998): 4 Scenarios Air temperature Precipitation 1 + 1°C - 15% 2 + 2°C - 20% 3 + 1°C + 20% 4 + 2°C - 15% Year: 2006. The working group of experts agreed that scenario 1 matches with the moderate scenario for the Vulnerability assessment study, assuming an increase of water transport of the Humboldt coastal current but keeping SST anomalies < 1oC, air temperatures will increase by 1°C, precipitation will be less than overage by 15% and there will be and increase of sea level of 0.3 m.