Investigation of Well Deepening Effects on Aquifer Yeild Using Numerical Model

Iran is located in a semi-arid area with an inappropriate distribution of water. In many parts of the country, particularly arid plains, the groundwater is the main source for supplying demands. One of these areas is Aliabad plain located in Saveh catchment in which farmers have been digging deep wells for withdrawal. Increase in withdrawal above the aquifer renewable water potential has caused a decrease in efficiency of the operation wells due to the groundwater drawdown. Decreasing in gtrounwater table will later lead to land settlement and environmentak impacts. In order to increase the well efficiency, well deepening has been carried out in the plain. This research simulated the effects of excessive withdrawal on operation wells efficiency using MODFLOW. The conceptual model and well deepening effect simulation were developed in GMS model. Results indicated that the north eastern and western regions of the aquifer have higher potentials for drying up and the maximum (critical) well deepening depth is about 80 meters for the whole area. The results also showed that by deepening the agricultural wells some parts of the aquifer will dry up which leads to migration.