Optimal Water Allocation among Agricultural Consumers Using Crop Pattern Change Approach to Improve Farmers' Livelihood

Qazvin plain is one of the areas in the country facing a severe shortage of water. In recent years, after the reduction of water allocation to this plain from Taleghan Dam, farmers have been digging illegal wells or over-harvesting existing wells in order to maintain their livelihoods. This has adverse effects, including severe depletion of wells, drying of aqueducts, salinity and degradation of groundwater quality, reduced yield of agricultural products, loss of soil quality, imposition of high costs on well owners, creating a major supply problem. Drinking water in cities and villages and eventually land subsidence (Qazvin Regional Water Authority, 2014). Studies show that the cultivation pattern in the last ten years has been almost constant and included wheat products, forage corn, canola, tomato, alfalfa, barley, sugar beet, peas, beans, potatoes, corn and lentils (Simiari and Mazandaranizadeh, 2017).Studies have shown that previous studies have either optimized water distribution or optimized cultivation patterns, but this study compared the differences between the two approaches to farmers' livelihoods in order to conserve groundwater resources.