Deep Seated Variation of Electrical Conductivity and The Border of Salt and Fresh Water in Chah_Deraz Plain Aquifer- Sirjan

One of the obstacles in the development of Gol-e-Gohar iron ore in Sirjan is the shortage of fresh water in the region. Chah_Deraz plain aquifer that located in adjacent of salty pan of Sirjan, is currently one of the sources of required water supply of Gol-e-Gohar mine, but salt water take in the lower aquifer, has limited the increasing withdrawals of fresh water. Optimal management and developing withdrawals of the aquifer requires knowledge of the placement position of the mass of salt water in the aquifer. This study tries to determine the status and border of salt and fresh water by reviewing hydrochemistry of aquifer and sampling of observation wells as deep and surface and measuring electrical conductivity. Groundwater level around exploitation wells is about 1685 meter and in output areas output of the plain is about 1690 meter. The situation of the border of the salt and fresh water exploitation wells in downstream is 1625 meter and around the exploitation wells at 1649 meter level was determined. Also groundwater model results show that by increasing the pumping wells twice, a drawdown of three meter is occurred around exploitation wells which in turn the salt water with electrical conductivity of more than 10000 μs/cm intrudes to the floor of exploitation wells.