Ground water recharge potential of the tasra block of chasnala—a case study

Abstract

Groundwater is one of the important sources of potable water. This accounts for a significant water resource in India for domestic, irrigation and industrial needs. Over 80% of the rural domestic water supply and 45% of the irrigation water supply in the country are met by this valuable resources. Besides quantity, groundwater quality is a serious problem in the country. In the present context, when ground water table level which is depleting every year, the study of its availability assessment becomes necessary. This assessment may be quite helpful in restricting our water requirement and leads us for the water requirement audit. Groundwater occurrence and storage in study area are mainly controlled by the geological set up of the area. The ability of geological formation to store and transmit water is dependent on its formation parameters, such as porosity and hydraulic conductivity. In the mining area, the water levels are bound to be affected and disturbed. The Jharia mining area is highly disturbed and the permeabilities of individual geological units are spatially variable and depend on lithology, fracturing and attenuation with depth. The porous and more open-jointed sandstone members tend to form aquifers, the shaly members are aquitards, which may be leaky but are poorly permeable and form the poor permeable barriers to the vertical groundwater movement. Rainfall is the principal recharge source to groundwater. Besides rainfall, the mine water discharge from the local mining areas and existing water bodies including water logged in abundant mine quarries are also contributed to the ground water recharge as return flow. The present work attempts to establish a hydrogeological framework for the understanding of natural groundwater recharge processes in relation to climate, landform, geology, and biotic factors. It begins with the concepts of groundwater flow systems, which form the basis for comprehending recharge processes. It then concentrates on the sources and mechanisms of groundwater recharge and stresses the importance of developing correct conceptualizations of recharge. The ground water recharge potential in the area was estimated by using rainfall-infiltration and water table fluctuation methods. The annual withdrawal of water for irrigational uses as well as domestic uses have been calculated and also the annual draft through mine discharge have been calculated. On the basis of these studies, net annual ground water availability assessment has been made.