Estimating Groundwater Recharge by HYDRUS-1D Model (Case Study: Hashtgerd)

Today groundwater resources play an important role in the water supply of agriculture. Iran is in the semiarid region so evaluation of irrigation that turns into groundwater resources that called the return flow could have a major role in groundwater recharge and must be considered for effective management of groundwater resources. The goal of this study was investigating the effect of irrigation on groundwater recharge by using the HYDRUS-1D model. In this case study, the data were obtained from a complete growing season of maize and wheat which were planted in the Hashtgerd Alborz Province during the years of 20004 2013. Soil moisture and deep percolation were simulated for two different irrigation efficiencies of 60 and 80 percent (equivalent to 40 and 20 percent deep percolation of irrigation, respectively). The results showed that soil moisture advance underirrigation efficiency increased the level of ground water to 1 m. Also the highest percentage of groundwater recharge from irrigation and rainfall was for winter wheat. During the simulation, irrigation efficiency of 60% and 80%, recharge 2.63 m and 1.6 m the ground water level that 14.6 and 10.92 percent are included irrigation and rainfall respectively. The results of this study showed that deep percolation of irrigation and rainfall can recharge and rise of the groundwater level.