Spatial mapping of groundwater potential in Ponnaiyar River basin using probabilistic-based frequency ratio model

Abstract

Water is a precious natural resource without it life is not possible. The demand for water has rapidly increased over the last few years and this has resulted in water scarcity in many parts of the world. The main aim of this study is to examine the application of the probabilistic-based frequency ratio (FR) model in groundwater potential mapping at Ponnaiyar River basin in Tamil Nadu, India. In the present study includes the analysis of the spatial relationships between groundwater yield and various hydrological conditioning factors such as altitude, slope angle, curvature, drainage, lineament, lithology, soil depth, and land use/land cover for this region. The eight groundwater conditioning factors were collected and extracted from topographic data, geological data, satellite imagery, and published maps. Then, the 74 groundwater data with high potential yield values of ≥40 m3/h were collected and mapped in GIS. Out these, 44 (60%) cases were randomly selected for models training, and the remaining 31 (40%) cases were used for the validation purposes. Finally, the frequency ratio coefficients of the hydrological factors were used to generate the groundwater potential map. The receiver operating characteristic (ROC) curve was drawn for groundwater potential map, and the area under curve (AUC) was computed. Results indicated that the rainfall and slope percent factors have taken the highest and lowest weights, respectively. Validation of results showed that the FR method (AUC = 78.90%) performed fairly good predication accuracy. Results of this study could be helpful for better management of groundwater resources in the study area and give planners and decision makers an opportunity to prepare appropriate groundwater investment plans for sustainable environment.