Using of Optimization Strategy for Reducing Water Scarcity in the Face of Climate Change

Abstract

Climate change is one of the most important factors that affect the availability of water resources in recent years. Many areas of the world are involved with droughts and water shortages due to climate change. Iran is one of the most notable areas in this field. The Zayandeh-Rud River Basin is of one of the most strategic areas in the central part of Iran in terms of water resources and consumption. In this study, the outputs of 15 GCMs related to the fourth assessment report of IPCC (AR4) are used for the analyzing the effects of climate change. A combination of the various GCM models is used through a weighting approach to generate the different climate change patterns including the ideal, medium and critical patterns. Then, the IHACRES model as a simple model designed to describe the dynamic response characteristics of catchments, was used to predict the natural inflow to the Zayandeh-Rud dam. Also, the Agro-Ecological Zones (AEZ) method that has been developed by the Food and Agriculture Organization (FAO) and International Institute for Applied Systems Analysis (IIASA), was used to determination of the effects of climate change on agricultural water demand. Based on the changes in the water resources and consumptions in the region, a non-linear optimization model was proposed to allocate the water between the different demands. The objective function was defined based on the minimizing of the water shortage during the next 30 years (2015–2044). The General Algebraic Modeling System (GAMS) software was used to solve this function. The results indicated that the annual water deficit of 610–1031 MCM will be occurred in different climate change patterns.