Assessment of possible risks of climate change on Seyhan Basin water resources based on meteorological data

In assessing the impact of climate change on water resources, the presence of numerous sub-criteria for identifying risk factors affecting these resources creates a complex problem that is difficult to analyze, resolve, and make decisions upon. The application of Multi-Criteria Decision-Making (MCDM) methods has gained increasing importance in addressing this series of problems. In this study, the Analytical Hierarchy Process (AHP), a GIS-based MCDM method, was utilized to identify the risk factors affecting water resources within the boundaries of the Seyhan Basin. During the data analysis phase of the study, AHP pairwise comparisons were conducted to determine the weight values of the research criteria. Using the obtained weight values, a Weighted Overlay analysis was performed on GIS software, and areas in the research site carrying risks such as drought, heavy precipitation, heatwaves, and topography were mapped and identified. As a result of the study, the prioritization of weights in the AHP analysis for the main risk factors was found to be %55,79 for drought, %26,33 for heavy precipitation, %12,19 for heatwaves, and %5,69 for topography. The analysis identified areas with very high drought risk covering %11,7 of the southern and coastal regions of the basin, areas with high heavy precipitation risk covering %8,5 of the central regions, areas with very high heatwave risk covering %1,3 of the southern and coastal regions, and areas with high topography risk covering %0,8 of the south-central regions. Based on the risk maps obtained, the most at-risk areas in the basin were identified as follows: for drought, the districts of Karataş, Seyhan, Yüreğir, Sarıçam, and Çukurova; for heavy precipitation, the districts of Feke and Aladağ; for heatwaves, the western part of Karataş district; and for topography, the Çukurova district. It was concluded that implementing improvements such as reducing sectoral impacts, restricting agricultural irrigation, reducing water consumption through new technologies, establishing systems that support the reuse of treated wastewater, and climate change adaptation activities could mitigate the severity of risk factors threatening water resources in these areas. Keywords: Risk analysis, AHP, GIS, Seyhan Basin, Water resources