Groundwater is the only perennial water resource available to rural communities, especially in semi-arid regions. This study aims to provide an overview of fluoride-contaminated groundwater in the Telangana, India, by predicting potentially affected areas. The prevalence of endemic fluorosis in different parts of Telangana has been widely reported. Therefore, it is necessary to demarcate the fluoride-affected areas to adopt the remedial measures. In this context, the available information on related environmental variables such as geological settings, hydro-morphological inputs, climatic information and soil properties have been integrated as thematic layers in an ArcGIS environment. The thematic layers and their features were assigned with suitable weights, which were normalised using the analytic hierarchy process to obtain final ranks and the weighted overlay analysis method was carried out to delineate the potential fluoride contamination (PFC) zones. The entire state was classified into four broad categories, i.e., very high (17.6%), high (15.8%), medium (32.7%) and low (33.9%), in terms of groundwater fluoride enrichment. A comparison of the output map and the reported data indicates that the PFC zone model could explain 68.7% of fluoride variation. This study is the first such attempt to offer a regional-scale PFC zone for an entire state and offers a first-hand insight into the severity of fluoride contamination.

A comprehensive geophysical and petrological study was carried out at Giddalur area in Prakasam district, Andhra Pradesh, which is geologically a highly deformed area and is difficult to delineate the aquifer zone(s). The task was to find out the exact rock type in which aquifer is concealed as well as to delineate the aquifer zone, which can yield sufficient quantity of water. The resistivity models derived from geophysical dataset were interpreted in terms of hydrogeology and the results revealed substantial resistivity contrast of the geological formations within the study area. We have delineated two major groundwater potential zones based on this study. These zones were tapped at different depths in diverse rock types. Drilled hand specimens (rock cuttings) were not adequate, so these specimens were petrographically studied to reveal the exact contact zones of the rock type. On integration of the geophysical and the petrographic results, it was illustrated that two aquifer zones were struck at a depth of 92 and 122 m between shale-phyllite and phyllite-quartzite, respectively. These findings were correlated, which matched with the lithology of the drilled borehole. This integrated approach will be helpful in strategy for groundwater assessment as well as prospecting groundwater resources in different geological terrain.