بررسی تاثیر سازندهای زمین‌شناسی بر روی کیفیت منابع آب زیرزمینی دشت اردبیل

The study area is located Caspian watershed. It is a large basin with average precipitation and temperature of ۲۹۱.۲mm and ۱۶.۱C in a time range of ۲۵ year. The ground_water resources have a vital role in supplying agricultural and industrial demands. There are ۲۸۶۳ active well, ganats and spring and ۱۳۳۵ inactive. The aim of this study is to analyze the water quality of the area and determine the effects geological formations on the hydrochimical deterioration of the ground_water quality in the area.Thus the ۱۷۲ samples of active water sources was used to hydrochimical analyze.The result shows the obvious effects salt and gypsious formations in easternnorth and westernsouth partsof the plain and effects of fine grain formations in some other parts of the plain, this caused to unusual increase in solute and Solfat  amount in northern and southern parts and fine grain formation in some parts of plain cause to ion exchange, decrease in hydrolic  conduntivity and unusual increase in cl^- amount. Eless the plain ground_water are divided in to ۳ parts totally that are convenient for agricultural, industrial and drinking.