Hydrogeological Characteristics and Model Conceptualization of Malaprbha Catchment, Karnataka, India
Groundwater development in weathered and fractured hard rock aquifers is a more complex and dynamic as compared with that in unconsolidated alluvial stratum or in soluble carbonate rocks. The fact is that the aquifers classified under hard rocks are discontinuous, anisotropic and have only secondary porosity. However, in India more than 65% of the region is covered by hard rocks, particularly in the southern part of the country which is dominated by basaltic lava flows. The farmers in this part of the region are always facing conditions of hydrologic extremes due to the uncertainty in the rainfall pattern added with climatic changes. In this context, it is highly essential to develop reliable and well-conceived models for estimating the groundwater availability and to guide the society for adapting to the worst scenario of water scarcity from time to time. For sustainable development, it is necessary to take up soil and water conservation techniques in each watershed, taking a sub-basin as the unit for planning. Therefore in the present study Malaprabha sub-basin in northern region of Karnataka has been studied systematically for groundwater hydrological parameters like rate of infiltration and Hydraulic conductivity varies with respect to land use and the lithology. The rate of infiltration in the forest area is high 13% compared hard and compact rock similarly the Hydraulic conductivity varies from 0.2 cm/hr in the barren land to 5.8 cm in the Forest area. Therefore these two factors mainly affect the groundwater recharge and movement with this experimental values conceptual model has been developed and found that in the upper part of the basin the rate of infiltration is high and groundwater occurs in the unconfined aquifers and in the middle part of the basin the groundwater occurrence is low and in lower portion the groundwater occurrence is considerably higher.