Investigation of hydraulic continuity and mixing between Urmia Water Lake and Shabestar coastal aquifer

Shabestar Coastal Plain is located eastern and northeast part of Urmia Lake East Azerbaijan. In the last few years a lot of pumping wells are contaminated by salt solution due to over-pumping of groundwater from the plain. The salty Urmia Lake is considered the most probable source for groundwater salinization because of the proximity to the aquifer. However other sources involving halite dissolution which is exposed at the southern end of Shabestar Plain are possible. Since bed rock of the aquifer are composed of clay and marl deposits so upconing is suspected another source for salinization. For determination of hydraulic continuity between the Shabestar Aquifer and Urmia Salty Lake, the log of the boreholes which are located at the west of Shabestar Aquifer and the border of Urmia Lake are considered. These are mostly comprises of impervious sediments mainly clay, silt and marl. In this region seems the most important factor (hydraulic conductivity) that there should be Urmia Lake water moved through porous media, does not existed.
In June 2014, Groundwater samples were collected from twenty six wells and four springs in Shabestar Plain to clarifying the origin of salinity. The analysis of samples showed that 36% of the water samples chlorinated and clustered within the brackish group. Cl/Br and Na/Cl weight ratio, in sea water and halite dissolution brines is 300 and 0.55 respectively. These diagrams showed that the main cause for the elevated salinity is sea water