Modeling water supply and demand balance of Istanbul under future climate and socio-economic change scenarios

Abstract

Population growth creates an increased freshwater demand with the subsequent developments due to urbanization and industrialization in the metropolis Istanbul, Turkey. Climate change has additional serious impacts on water resources. Therefore, sustainable water management practices are required to cope with the dynamic socio-economic change and climate change on water demand and supply balance in Istanbul. In this study, Water Evaluation and Planning Systems (WEAP) modeling program, as an Integrated Water Resources Management (IWRM) tool, is used to understand the impacts of climate change and socio-economic changes such as population growth and water use on water demand and supply balance and to know what awaits Istanbul until 2100. The model is analyzed under different scenarios of socio-economic and climate change. The physical and spatial properties of the watershed basin and catchment hydrology data appropriate with Rainfall Runoff (Simplified Coefficient) Method of WEAP are used in the baseline scenario construction and scenario analysis. Regarding the results, the city is expected to experience the negative impacts of climate change much more after 2030 while the impacts will get more dispersed and unpredictable after 2040. The high dependency on the external water resources, especially on Melen River, is increasing the water insecurity of the city especially with the pressure created by increased total water demand of the city. To achieve a water-smart society under the increasing pressures of climate change and socioeconomic changes; technological improvements, policy changes and educational activities to increase environmental awareness are needed with the joint contributions of all stakeholders.