Concerning the increasing demand for water in arid and semiarid regions, especially in the field of agriculture, an analysis of irrigation efficiency plays a vital role. One of the most important approaches for increasing efficiency in agriculture is to develop modern systems and use them to replace traditional irrigation methods. Tuyserkan Plain is located in Hamadan province, Iran, that is faced with a severe decline of groundwater level. Irregular use of groundwater for agricultural needs and low-efficiency irrigation systems are believed to be the main reasons. In this study, the efficiency of traditional and modern irrigation systems is first analyzed. An irrigation efficiency scenario is presented in order to simulate irrigation efficiency increase effects on the level of groundwater in the aquifer. The irrigation efficiency scenario is simulated using the MODFLOW and WEAP models and is compared to the reference scenario (Current irrigation efficiency is maintained). Although groundwater level declines in both scenarios, the simulation showed that in the reference scenario, groundwater level decrease becomes significantly slower and, as a result, the aquifer will recover.
