Determining the Appropriate Recharge in Damghan Plain, Iran to Prevent from declining of Water Table

Recently using of groundwater, as the main resource of fresh water without considering the whole situations may cause it to have significant problems. Unconfined aquifer of Damghan Plain, which is located the vicinity of the Central Desert of Iran, used without any methodical discharge, so it has seriously faced to drawdown of water table and resource deficiency. This research has been done to determine the appropriate recharge of it, not only to use of it but also not to cause any undesirable changes in environment. In this survey by using Fuzzy method three models which are divided into nine submodels have been made. In each submodels two inputs and one output have been identified, the value of recharge, drawdown and discharge are consequently supposed as them. In this survey the fluctuation of water table in three groups has been organized such as low [0-0.7], intermediate [0.7-3/5] and high [3.5-7]. In each submodels of every model the values of recharge consequently are 11, 21 and 31 MCM; that the first value is the natural recharge and the others are the resource deficiency. By changing of water table, it is possible to get different outputs as the discharges. This operation has been done twelve times for each submodels, so twelve points have been obtained as the various discharges. Then these points are distributed by the power of two and three fitness functions. Ultimately the appropriate recharge to compensate the shortage of resource is defined 21 MCM.