Groundwater Potential Mapping in a Rural River Basin by Union (OR) and Intersection (AND) of Four Multi-criteria Decision-Making Models

Targeting groundwater in the river basin like Chandrabhaga with seasonal drought is a very urgent task especially for mitigating irrigation demand during the non-monsoon period. This paper delineated suitable groundwater potential zones based on the analytical hierarchy process (AHP), modified AHP, PCA-based weight and knowledge-based weight of multiple input parameters. For providing more certainty of the target zones in the derived models, union and intersection of all models were performed. A GIS-based multi-criteria approach using 13 relevant parameters has been adopted in this work. From the first four models, it is found that very suitable areas vary from 7.5 to 11% of the total basin area. The union and intersection models of the four individual models, respectively, delineated 13.91% and 3.69% suitable areas. Among the six models, the average yield of groundwater (5.96 L/s) is maximum in case of the intersection model, which is, therefore, more reliable than others. In case of the union model, the suitable area has 0.2 L/s less average yield than the intersection model. Therefore, for the harvesting more water, very good potential area delineated in the intersection model can be targeted. All these models will nevertheless help decision-makers to judge whether the existing groundwater harvesting structures are located properly or whether reorientation is needed.