management of Zarringol plain in Golestan province by using ground water model

Zarringol plain with an area about365km2is part of the Gorganrood catchment in Golestan province which Alborz mountains is mainly supply this aquifer. However in places with high amount of precipitation، most of the aquifers seem under equilibrium condition، but planning and management decisions are still important as well as arid places. In this regard، the model could be an efficient tool to evaluate different management options were explored and utilized. In this study، the variation of groundwater level was simulatedbyGMS7. 1in steady state (1 month) and unsteady state (5 years). The results showed that the model can be used with high accuracy (RMSE=0. 98) and in this condition، the calculated water levels by model are very close to observed values. After ensuring the accuracy of the model، for managing the aquifer in better way in future a scenario was considered. This scenario aimed to determine the variation of groundwater according to reducing precipitation، the results showed that the10% reduction in amount of spring rainfall results to reduction of water level by 17 cm، which is much more than reduction of water level in the summer.