An Investigation of the Effect of Precipitation on the Groundwater Table

The Plain of Tuiserkan is located at a semi-arid climatic regime. During the last five years, overexploitation of underground water has caused more than 22 meters depletion of groundwater water level in this region. The role of water management is very important in this plain. To study the changes of groundwater, the annual and perennial hydrograph and water balance were investigated in the study area. According to the annual unit hydrograph, the level of underground water has dropped 1.98 meters yearly and 7.57 meters perennially. Annual changes in aquifer capacity has been 20.97 million cubic meters of water and for the 91-92 water year, it has been about 12.99 million cubic meters. Therefore, by continuing such a decreasing trend in the plain, it will be facing a water crisis in the next few years. To investigate the effects of precipitation and snow cover on the groundwater levels the artificial neural network model was used. The results showed neural network model has the lowest error index for snow cover data and monthly and three months later discharges with the correlation coefficient of 0.45 and error percentage of 0.028 can be appropriately predicted.