Determining the optimum drilling sites for groundwater wells based on the hydro-geoelectrical parameters and weighted overlay approach via GIS in Salah Al-Din area, central Iraq

Groundwater is one of the most precious assets for supplying water to the world's population. The main goal of this research paper is to use the GIS technique to determine the best drilling sites for new groundwater wells, based on hydro-geoelectrical factors and using a weighted overlay approach. Weighted Overlay Approach (WOA) assessment is a geographical approach for analysing multiclass charts, that are influenced by the various relevances of every layer as well as the classification of a layer. The advantage of WOA is its ability to makes the more favourable criteria with the higher values in the output raster, that help thereafter identifying those locations as the priority. The aquifer hydro-geoelectrical parameters such as resistivity, thickness, depth, and transmissivity.obtained by using the vertical electrical sounding (VES) technique allow together to determine the best locations for drilling.    The GIS technique is conjointly used herein to accurately identify the best location for the aquifers using the mentioned hydro-geoelectrical data. Weighted overlay has been applied to normalize the criteria layers, and blende to finally generate the suitability maps. The geospatial datasets are combined by using GIS to create and establish a suitability chart for determining efficient suitable locations for drilling successful water boreholes. The most suitable locations have been well recognized. The study area is divided into four categories: poorly suitable, fairly suitable, suitable, and excellently suitable. The different findings of this research can be consequently used to plan effective groundwater management in the region.