Different variations of groundwater levels in karstic areas of Izeh and Lali, north of Khuzestan, with emphasis on remote sensing

The 10-year drought event from 2007 to 2017 caused a completely different behavior of groundwater of the Ilam-Sarvak karstic aquifers in northern Khuzestan in two regions Izeh (with a drop of about 120 meters) and Lali (with a drop of about 20 meters). In this paper, the drawdown in the Izeh karstic aquifers and the reduction of discharge of karstic wells are compared to the Lali aquifer based on their hydrogeological behavior. Groundwater data were collected and corrected in five calcareous wells. The hydrographs of the depth of the water wells have been prepared and the average annual and total drawdown in the two regions have been compared. In order to identify the reason for the significant difference in drawdown of groundwater level in the studied aquifers, the lineaments were extracted using ArcGIS satellite images using Bing satellite imagery. The average drawdown of Shavish and Tanush karstic aquifers in Izeh is 129.1 meters, and in the Gurpi anticline, Lali, is about 17 meters in the 10-year period of drought. The main reason for the difference between the hydrogeological behaviors of these two regions is related to the different lithology of the Ilam and Sarvak formations, the thickness of the layers, and the different fragility properties of these two formations in the two regions, which creates a karstic aquifer with a very good potential in the Lali area