The Determination of Ground Water Balance (GW) Using Modeling Flow, A Case Study West of Karbala Province

Abstract

     Water shortage is one of the serious environmental problems in a semi-arid region, which has become increasingly dangerous. The article considers a new management simulation model of Groundwater (GW) resources using a water flow model. One thousand one hundred fifty irrigation wells were selected as a study area using Landsat 8 OLI images 2016-2021 in the West of Karbala province, Iraq. Geographic Information System tool integrated with numerical /conceptual model using the Visual MODFLOW Flex 7 software to reach the optimal use of GW resources. The conceptual model indicated that the value of the flow in the aquifer reaches 21 million cubic meters annually, which means there is renewable storage. The consumer value of GW was about 55 million m3/year. The result presented that the value of the lost and depleted storage in this part becomes about -34 million m3/year, which is the value of the variation in the underground storage, meaning there is a significant depletion of GW in the study area. Using the Visual MODFLOW Flex 7 software and entering parameters for the study area through pumping and monitoring wells, an error of 0.067 m was achieved in estimating groundwater recharge places near the folds' rocky aquifers. The normalized RMS for the model was 69.595%, and the correlation coefficient was 0.391. The contour lines in the region's East indicate increased conductivity due to channels and openings formed during groundwater-bearing rocks, depressions, and lakes. The study concluded that the outputs could help water administrations for more accurate and sustainable plans and management of GW resources in the Karbala area.