Modeling the Hydrogeological Relationship of Sahneh-Bistoon Plain Aquifer with Gamasiab River and Aquifer Management

Excessive population growth over the past three decades, limited surface water resources, agricultural, industrial, urban activities and excessive exploitation of aquifers have caused irreparable damage to Iran''s water resources regarding quality and quantity. To prevent the continuation of quantitative and qualitative decline, management of exploitation and protection of groundwater should be the basis of planning in the country. Groundwater management requires an adequate understanding of the aquifer system and the use of a tool that can simulate the response to the various quantitative and qualitative stresses of the aquifer in the current and future conditions. In this regard, by using the model, real conditions in nature can be simulated with good accuracy and achieved to acceptable results. The study area of Gamasiab is located in Sahne-Bisotun plain in the northeast of Kermanshah province. In this area, only one case investigated in a small part of the aquifer. In this study, the status of the aquifer and the relationship between surface and groundwater in the entire aquifer zone of Sahneh-Bistoon plain simulated with the use of the MODFLOW 2000 code, the GMS v10 software. The results of the model show that the water budget of Sahneh-Bisotun plain is negative in the year 88-87 and is 22.81 million cubic meters per year. The river is the main factor that recharges the aquifer, which is 248.8 million cubic meters per year, and pumping from water wells is the most crucial factor in the drainage of aquifers, which is 36.4 million cubic meters per year. The results of the model show that the Gamasiab River recharges the aquifer in two reaches and drains the aquifer in other reaches. The river drains 15.55 million cubic meters of water per year from the aquifer.