A GIS-based SINTACS model for assessing intrinsic groundwater vulnerability of the Alton Kopri basin, Kirkuk governorate northeast of Iraq

Abstract

The Alton Kopri Basin is an important and significant water basin in Kirkuk governorate where most of the area demand like drinking, agricultural, grazing, and industrial are depending on it. the basin consist of two main aquifers the upper aquifer formed by Quaternary deposits and the lower confined aquifer formed by Muqdadyi and Bai Hassan formations, the hydrological conditions for the lower aquifer changed laterally from confined to semi-confined down to unconfined from the center of the basin to northeast of the area. Flow direction from northeast to northwest coincident with topographic elevation trend. The annual groundwater recharge estimated by chloride mass balance method is (124 mm).It is important to assess the potential of ground water for pollution. For this purpose intrinsic vulnerability was assessed using SINTACS model with the aid of geographic information system (GIS) techniques. The final results show that two zones moderate and high vulnerability classes dominant the study area in the case of normal scenario occupied area are 423 km2 and 649 km2 respectively, the relevant scenarios represents with two categories, moderate category occupy 491 km2 and high category occupy 549 km2. Three zones low, moderate, and high characterizes the nitrate scenario with 77 km2, 523 km2 and 440 km2 respectively, the SINTACS is the most subjective because of the wide range of the rating of some parameters. The high vulnerability zone exists in the most part of the basin center, where the unconfined upper aquifers exist. Accordingly, the impact of aquifer media, soil texture, and vadose zone is the most effective parameters in SINTACS model.