Creating the Distribution Map of Groundwater for Drinking Uses Using Physio-Chemical Variables; Case Study: Al-Hilla City, Iraq

Surface water and groundwater are significant for population and other activities due to the decreasing surface water flow toward Iraq. Therefore, there is a need to analyze groundwater’s quality and classification and its applicability as an alternative in various human activities in the study area. This study utilized the groundwater quality index model for drinking uses (GW.Q.I.) and entered the resulting values in the GIS environment. This model was applied to 56 wells in Al-Hillah city by measuring twelve variables in each well. The measured variables were calcium (Ca), magnesium (Mg), sodium (Na), chloride (Cl), sulfate (SO4), bicarbonate (HCO3), total hardness (TH), total dissolved solids (TDS), nitrate (NO3), and electric conductivity (EC). The prediction map of GW.Q.I. was produced in the GIS. Then, the distributing map was divided into six categories based on the suitability of groundwater for drinking uses. The areas’ values of six categories with their ratings were about 5 km2 (excellent), 122 km2 (good), 610 km2 (poor), 63 km2 (very poor), 36 km2 (contaminated), and 24 km2 (very contaminated). For the entire study area, the average value of the GW.Q.I. was 177, classified as poor for drinking uses.