Developing an Agricultural Planning Model in a Watershed Considering Climate Change Impacts

Abstract

Societies are facing major challenges in allocating water resources to growing water demands due to population growth and industrial and agricultural developments. With increasing water scarcity, the need to increase agricultural water productivity is receiving significant attention in developing countries. Among alternative options for meeting increasing water demand, improving productivity has received considerable attention. Therefore, planning of water systems to face future development conditions needs further studies on land, water use, and resources as well as consideration of objectives to maximize crop production to achieve the maximum net return. Because climate change is likely to have impact on the hydrological cycle and consequently on the available water resources and agricultural water demand, there are concerns about the effects of climate change on agricultural productivity. Considering climate change impacts, in order to optimize agricultural productivity, practical frameworks and models based on comprehensive researches and studies need to be developed. The goal of this study is to develop an agricultural planning model in order to optimize the cultivated area, crop pattern, and irrigation efficiency based on the estimations of crop water requirements, water availability, and water allocation to irrigation. For this purpose, the Aharchay watershed located in the northwestern part of Iran is selected as the case study. For crop water requirement estimation, the output of an atmosphere-ocean general circulation model statistically downscaled and used as inputs to a computer model. Then water supply resources are assessed using a water allocation planning tool. The results of this study show the significance of integration and using different tools and methods in assessing and allocating water resource in regions with limited or scarce water resources.