Comparison of multi-influence factor, weight of evidence and frequency ratio techniques to evaluate groundwater potential zones of basaltic aquifer systems

Abstract

Groundwater is the largest available reservoir of freshwater. But the rapid increase in the population and urbanisation, has led to over exploitation of groundwater which imposed tremendous pressure on global groundwater resources. Because of the hidden and dynamic nature of groundwater, it requires appropriate quantification for the formulation of groundwater planning and management strategies. The present study evaluates the efficacy of geospatial technology based Multi Influence Factor (MIF), Weight of Evidence (WofE) and Frequency Ratio (FR) technique to evaluate groundwater potential using a case study of basaltic terrain. The thematic layers influencing the groundwater occurrence viz. rainfall, slope, geomorphology, soil type, land use, drainage density, lineament density, and elevation were prepared using satellite images, hydrologic, hydrogeologic and relevant field data. Based on the conceptual frameworks of MIF, WofE and FR techniques these thematic layers and their features were assigned with appropriate weight and then integrated in the ArcGIS platform for the generation of aggregated raster layer which portray the groundwater potential zones. The results of validation showed that the groundwater potential delineated using MIF technique has a prediction accuracy of 81.94%, followed by WofE technique (76.19%) and FR techniques (71.43%). It is concluded that for evaluation of groundwater potential, the MIF technique is most reliable, followed by the WofE technique. The evaluated groundwater potential zones are useful as a scientific guide to identify the suitable location of wells and recharge structure in a cost-efficient way and also for the development of structured and pragmatic groundwater management strategies.