K. Brindha

Spatial and Temporal Variation of Groundwater Level and its Relation to Drainage and Intrusive Rocks in a part of Nalgonda District, Andhra Pradesh, India

Drainage and lineaments play an important role in the flow of groundwater. The objective of this study is to assess the groundwater level and its relation to drainage and lineaments in a hard rock region of a part of Nalgonda district, Andhra Pradesh, southern India. The region predominantly comprise of granites and gneisses. Groundwater level was measured in 42 representative wells in this study area from March 2008 to January 2010 once in every two months. Observed groundwater levels were compared with drainage and dyke density. Groundwater level fluctuation in low drainage density region is generally greater than those in moderate and high drainage density regions. The dykes do not act as barriers for groundwater flow as they are highly weathered. The quantity and flow of groundwater in this region is predominantly controlled by drainage density, intensity of weathering and presence of fractures. Thus the study indicate that the drainage density play a major role in groundwater level fluctuation and as the dykes are weathered, they do not affect the groundwater flow in this shallow unconfined aquifer.

Assessment of Background Uranium Concentration in Groundwater Around a Proposed Mining Area

This study was carried out in and around a proposed mining area (Lambapur and Peddagattu) located in Andhra Pradesh, India with the aim of assessing the spatio-temporal variation and the impact of rainfall on uranium concentration in groundwater. The concentration of uranium in groundwater varied from 0.2 to 77.4 ppb. There was significant increase in uranium concentration in groundwater after rainfall which was due to the leaching of uranium ions present in the unsaturated zone along with rainwater. The reason for the presence of uranium in groundwater of this region is highly localized that depend on the lithology inherent to this region.