A study of mineralized water using geophysical and hydrogeochemical approaches in Khwelen salt ponds, Sangaw, Sulaymaniyah, NE of Iraq

Abstract

Groundwater is the main source of Khwelen village for domestic and household purposes, furthermore for salt production via salt evaporation ponds. Electrical Resistivity Tomography (ERT) and hydrogeochemical approaches are used to understand the regime and distribution patterns of different types of mineralized water flowing through several springs and wells in a restricted area does not exceed 0.14 Km². The high salty one using for producing salt for more than hundreds of years and the sulfurous one that has bad odder. The area is covered by Fatha Formation which has four types of depositional cycles, two of them are considered as impermeable layers they are claystone and marlstone, the others are Limestone and Gypsum layers that characterized by highly fractured and caverns. The inverse sections of the resistivity imaging showing the occurrence of 22 caves of different sizes and at different depths. They are classified into two groups, 10 cavities detected in the Gypsum layers showing high resistivity ranging from 350 Ohm.m to 1200 Ohm.m, they are most probably making the underground paths of the sulfurous groundwater. The second group is 12 cavities appear in the limestone layers of the Fatha Formation and they are showing very low resistivity ranging from 0.4 Ohm.m to 4 Ohm.m and forming excellent paths of the high salty underground water. ERT shows high applicability for finding the boundary between the saline and sulfurous mineralized water.

The groundwater chemistry is controlled by many overriding factors which are: dissolution, mineral precipitation, cation exchange, and salinization, besides the effects of localized topography, mixing, and geology. These processes are proved from the results of ionic concentrations, saturation indices, HFE diagram, and oxygen and hydrogen stable isotopes.