The study looks at soil moisture movement and recharge to groundwater using nuclear methods like tritium tagging. It estimates the recharge to groundwater due to monsoon rain and irrigation through the unsaturated porous media in case of cultivated and uncultivated fields.
The geohydrological data indicates three aquifer systems in this region – shallow (60 ft bgl), intermediate (70-150 ft bgl) and deep (300-500 ft bgl). The field level study involved injection of artificial radioisotope at two uncultivated and six cultivated sites before the onset of monsoon. The soil samples were collected from the injection points after the rainy season.
The results of recharge to groundwater in uncultivated land vary from 3 % to 5 % while in cultivated land it is in the range of 8 % to 17 %. The values of recharge to groundwater seem justified keeping in view the type of soil and other geo-hydrological conditions prevailing in the study area.
Further studies using neutron moisture probe and environmental isotope will throw more light on the interconnections of different aquifer systems, locations of recharge zones to deeper aquifers and major recharge sources.
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