Climate change impacts on snow water availability in the Euphrates-Tigris basin

Abstract

Abstract. This study investigates the effects of projected climate change on snow water availability in the EuphratesTigris basin using the Variable Infiltration Capacity (VIC) macro scale hydrologic model and a set of regional climatechange outputs from 13 global circulation models (GCMs) forced with two greenhouse gas emission scenarios for two time periods in the 21st century (2050 and 2090). The hydrologic model produces a reasonable simulation of seasonal and spatial variation in snow cover and associated snow water equivalent (SWE) in the mountainous areas of the basin, although its performance is poorer at marginal snow cover sites. While there is great variation across GCM outputs influencing snow water availability, the majority of models and scenarios suggest a significant decline (between 10 and 60 percent) in available snow water, particularly under the high-impact A2 climate change scenario and later in the 21st century. The changes in SWE are more stable when multimodel ensemble GCM outputs are used to minimize intermodel variability, suggesting a consistent and significant decrease in snow-covered areas and associated water availability in the headwaters of the Euphrates-Tigris basin. Detailed analysis of future climatic conditions point to the combined effects of reduced precipitation and increased temperatures as primary drivers of reduced snowpack. Results also indicate a more rapid decline in snow cover in the lower elevation zones than the higher areas in a changing climate but these findings also contain a larger uncertainty. The simulated changes in snow water availability have important implications for the future of water resources and associated hydropower generation and land-use management and planning in a region already ripe for interstate water conflict. While the changes in the frequency and intensity of snowbearing circulation systems or the interannual variability reCorrespondence to: M.Özdogan (ozdogan@wisc.edu) lated to climate were not considered, the simulated changes in snow water availability presented here are likely to be indicative of climate change impacts on the water resources of the Euphrates-Tigris basin.

Water Security in the Middle East : Essays in Scientific and Social Cooperation

“…The discharge of the Euphrates and Tigris Rivers is also expected to decline because of decreased precipitation and increased evaporation brought about by climate change (Bozkurt and Sen 2013 ;Özdo ğ an 2011 and Tigris Rivers are heavily dammed, their capacity to absorb disturbances brought about by climate change is weaker than less dam-impacted basins (Bozkurt and Sen 2013 ). Increased sedimentation from fl ooding is expected to decrease the reservoir's life span, which can ultimately increase the risk for dam failures or breaches that threaten downstream livelihoods.…”

Drought Analysis and Water Resources Management Inspection in Euphrates–Tigris Basin

“…The marshlands have been desiccated through the combined actions of upstream damming in riparian countries as well as the development of extensive downstream drainage projects, in the past 30 years [3]. Without doubt Turkey is in the strongest position with regard to its potential control of a large part of the water resources of the ETB mainly due to the Southeast Anatolia Project (GAP).…”

“…Very low precipitation caused a steep decline in agricultural productivity in the rain-fed ET drainage basins and displaced hundreds of thousands of people [2]. Climate change could seriously affect the water resources and lead to serious disputes among the countries that have territories in the ETB [3]. Bozkurt and Sen [1] investigated future climate change in the ETB and found that Turkey and Syria are most vulnerable to climate change, and downstream countries, especially Iraq, suffer more because they rely on the water released by the upstream countries.…”

“…The recent drought that began from 2003 has further strained the limited water resources in the region [7]. Voss et al [8] used Gravity Recovery and Climate Experiment (GRACE) satellite mission and [8] concluded an alarming rate of decrease of approximately -2.7 cm/yr water height, equal to 143.6 km 3 , in the total water storage from 2003 to 2009. SPI 1 is an index for extract drought periods that considers precipitation only and the negative values of SPI indicate droughts.…”

Hydrologic Impacts of Ensemble-RCM-Projected Climate Changes in the Athabasca River Basin, Canada

“…Climate change has significant implications on water resources and freshwater ecosystems Özdogan 2011). Regional climate models (RCMs) and macroscale hydrologic models (MHMs) are common approaches to investigate the effects of projected climate changes on local hydrological regimes.…”