GROUNDWATER POTENTIAL ZONES DELINEATION USING AHP AND GIS TECHNIQUES, FOR THE AL-AJEEJ DRAINAGE BASIN, NORTHWEST IRAQ
The climate variability severely affects the factors influencing groundwater recharge. The unreliable seasonal and poor quantities of the surface water resources tend to increase the decline in the groundwater levels. Therefore, it is necessary to delineate the groundwater potential availability (GWP), which can be used to augment the groundwater source.
The analytical hierarchy process (AHP) technique, as a popular method, is applied to determine the importance of groundwater influencing factors. To integrate the groundwater influencing spatial dataset, all the geospatial datasets preparation was carried out in the Geographic Information system (GIS) environment.
The Al-Ajeej drainage basin was chosen in this research to delineate the groundwater potential zones, where the groundwater serves as the main source for domestic and agricultural uses more than the seasonal surface water. Seven thematic layers of the influencing factors, such as rainfall, lithology, geomorphology, elevation, lineament density, slope, and drainage density, have been selected to assess groundwater potential zones (GWPZ) for the Al-Ajeej drainage basin.
Three GWPZ have been concluded, comprising “Good”, “Moderate” and “Poor”. The Good GWPZ is developed in the northern and southeastern parts; the Moderate GWPZ is distributed in the north and southwestern parts, while the Poor GWPZ is significant on the southern slopes of Sinjar Mountain and a small area in the most western part.