Groundwater Aquifer Suitability for Irrigation Purposes Using Multi-Criteria Decision Approach in Salah Al-Din Governorate/Iraq

In this study, GIS-based Multi-Criteria Decision Approach (MCDA) is used to identify suitable locations to use groundwater for irrigation purposes in Salah-Al-Din Governorate, 180 km to the North of Baghdad, capital of Iraq republic. Various criteria are adopted including Electrical Conductivity (EC), Power of Hydrogen (pH), Sodium percentage (Na%), Sodium Adsorption Ratio (SAR), Magnesium Adsorption Ratio (MAR), Kelly's Ratio (KR), climate factor, aquifer thickness, and aquifer elevation. Three datasets are integrated to produce the suitability model, including geophysical data, groundwater wells data and satellite-based climate data. The criteria layers are assessed using the multi-criteria decision approach by combining them together using the weighted overlay function in ArcGIS 10.5. Appropriate weights assigned and integrated into GIS to create the groundwater suitability map for irrigation. Finally, the suitability of the study area for irrigation purposes with its percent to the total area is classified into three classes according to the set criteria used for this purpose: high suitability (35.41%), low suitability (44.22%), and unsuitable/excluded (20.37%).