Comparison of drought effects on karst hydrogeology of asmari and Ilam-Sravak formations in southwest of Izeh

The drawdown of water table in the karst aquifers are caused by continuous droughts since 2007. In this research, different responses of the Ilam-Sarvak (Tanush and Shavish anticlines) and Asmari (Kamarderaz and Chalkhoshk anticlines) karst aquifers in southwest of Izeh were inquired to the decrease of precipitation recharges. The precipitation, and water level data, the pumping tests in seven karst wells, and the autocorrelation analysis on hydrogeologic time series were applied to the study of the hydrodynamic behaviors of the karst aquifers. The analysis of the representative well hydrographs indicates that drawdown in Asmari and Ilam-Sarvak karst aquifers were 1 and 140 m, respectively, from 2007 to 2009. The double porosity function of Ilam-Sarvak Formation and the base flow in Asmari Formation were deduced from the autocorrelation and pumping tests interpretations.