Abstract. The basaltic aquifers of the Upper Bhima River basin in southern India are heavily utilized for small-scale agriculture but face increasing demand-related pressures along with uncertainty associated with climate change impacts. To evaluate likely groundwater resource impacts over the coming decades, a regional groundwater flow model for the basin was developed. Model predictions associated with different climate change and abstraction scenarios indicate that the continuation of current rates of abstraction would lead to significant groundwater overdraft, with groundwater elevations predicted to fall by −6 m over the next three decades. Groundwater elevations can however be stabilized, but would require 20-30 % of the mean surface water discharge from the basin to be recharged to groundwater, along with reductions in pumping (5-10 %) brought about by improved water efficiency practices and/or shifts towards lowerwater use crops. Modest reductions in pumping alone cannot stabilize groundwater levels; targeted conjunctive use and improved water use efficiency are also needed.

Coastal lands around Bay of Bengal in Central Godavari Delta are mainly agriculture fields and two times annually paddy crops putting in the study area. Canals of Godavari River are the main source of water for irrigation. Geophysical and geochemical investigations were carried out in the study area to decipher subsurface geologic formation and assessing seawater intrusion. Electrical resistivity tomographic surveys carried out in the watershed-indicated low resistivity formation in the upstream area due to the presence of thick marine clays up to thickness of 20–25 m from the surface. Secondly, the lowering of resistivity may be due to the encroachment of seawater in to freshwater zones and infiltration during tidal fluctuation through mainly the Pikaleru drain, and to some extent rarely through Kannvaram and Vasalatippa drains in the downstream area. Groundwater quality analyses were made for major ions revealed brackish nature of groundwater water at shallow depth. The in situ salinity of groundwater is around 5,000 mg/l and there is no groundwater withdrawal for irrigation or drinking purpose in this area except Cairn energy pumping wells which is using for inject brackish water into the oil wells for easy exploration of oil. Chemical analyses of groundwater samples have indicated the range of salt concentrations and correlation of geophysical and borehole litholog data in the study area predicting seawater-contaminated zones and influence of in situ salinity in the upstream of study area. The article suggested further studies and research work that can lead to sustainable exploitation/use and management of groundwater resources in coastal areas.

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Cite this article as: L. Surinaidu, V.V.S. Gurunadha Rao, N. Srinivasa Rao, S. Srinu, Hydrogeological and groundwater modeling studies to estimate the groundwater inflows into the coal Mines at different mine development stages using MODFLOW, Andhra Pradesh, India, Water Resources and Industry, http://dx.Abstract The Singareni Collieries Company Ltd (SCCL) is exploiting coal in the Godavari valley coal fields spread over 5.33 km 2 in Andhra Pradesh, India. In the area, six workable coal seams have been identified in Barakar formation by the analysis of the geologic logs of 183 bore wells. A finite difference based numerical groundwater flow model is developed with twenty conceptual layers and with a total thickness of 320 m. The flow model was calibrated under steady state conditions and predicted groundwater inflows into the mine pits at different mine development stages. The groundwater budget results revealed that the mining area would receive net groundwater inflows of 5,877 m 3 /day, 12,818 m 3 /day, 12,910 m 3 /day, 20,428 m 3 /day, 22,617 m 3 /day and 14,504 m 3 /day at six mine development stages of +124 m (amsl), +93 m (amsl), +64 m (amsl), +41 m (amsl), +0 m (amsl) and -41 m (amsl) respectively. The results of the study can be used to plan optimal groundwater pumping and the possible locations to dewater the groundwater for safe mining at different mine development stages. 2

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