Development of the optimal cultivation pattern to manage changes in the groundwater level using fuzzy ideal planning models (Study area: Qom-Kahak)

Abstract

Abstract Planning for the optimal use of water and soil resources, in addition to their protection, will lead to increased production, growth of farmers' income, and economic prosperity. Modifying and proposing the optimal model of cultivation that reduces water consumption and increases the efficiency of its use is one of the requirements of most of the critical plains. The current study aims to provide the optimal cultivation model by the groundwater resources in the aquifer level of the Qom-Kahak study area to compensate for the long-term cumulative deficit of the aquifer and to emphasize the indicators of agricultural sustainability in the twenty-year planning horizon. After preparing information about the cultivated area, the production cost and selling price of major agricultural products were estimated. Also, the net irrigation requirement was calculated in terms of irrigation efficiency. To simulate the behavior of rainfall components from different scenarios, the outputs of scenario A2 of the HADCM3 climate model were used, and by using the balance continuity equation, the amount of water that can be allocated to the agricultural sector each year was estimated. Then, by using fuzzy ideal planning models, sustainable agricultural patterns were presented in the framework of technical limitations. The results showed that the current cultivation pattern is not in an optimal state and also the current exploitation rate is more than the amount of aquifer recharge. If this scenario is implemented, 536 MCM of the reservoir deficit will be compensated for the sustainability of the groundwater and it is predicted this amount will increase to 941 MCM at the end of the planning horizon.