Modeling groundwater probability index in Ponnaiyar River basin of South India using analytic hierarchy process

In the present study, an effort has been made to investigate the analytical hierarchy process has been applied to delineate groundwater potential based on integrated geographic information system (GIS) and remote sensing (RS) techniques in Ponnaiyar River basin, Tamil Nadu, India. At first, the climatic factor, topographic factors, water related factors, geological factors, hydrogeological factors and other ecological factors such as land use/land cover and soil depth were derived from the spatial geo-database. Secondly, the 74 groundwater data with high potential yield values of >= 40 m(3)/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. Then, the assigned weights of thematic layers based on expert knowledge were normalized by eigenvector technique of AHP. To prepare the groundwater potential index, the weighted linear combination (WLC) method was applied in GIS. Finally, 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 AHP method (AUC = 76.90 %) 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.