Impact of Rainfall and Soil Infiltration on Groundwater Dynamics of Yerekoppi-1 Micro-watershed, Haveri District, Karnataka, India

Abstract

The amount of water infiltrating the soil surface directly affects the quantity of surface runoff and erosion, and the recharge of both soil and groundwater. Groundwater recharge is an informative indicator of the water located beneath the ground surface. It has a direct impact on renewable supplies of groundwater. In the present study on Impact of rainfall and soil infiltration rate was used for effect on the groundwater level of the Yerekoppi-1 micro watershed (Manakur sub-watershed) in Haveri district of Karnataka state. Average annual rainfall is 700.7 mm and mean potential evapotranspiration is 1541.8 mm. An area of about 888 ha (94.32 %) has clay texture at the surface and 53 ha (5.68%) area has contributing settlement. In Yerekoppi-1 micro- watershed, 38 borewells are there in the vicinity of major stream of the micro- watershed. The mean depth of groundwater levels in the micro- watershed were monitored at a monthly frequency during January-2023 to March-2024. It was found that the maximum average depth of bore wells are about 17.6 mbgl and lowest average depth of borewell about 8.8 mbgl. Soil infiltration rate was measured at upper, middle and lower reaches of the watershed area in the year 2023 and 2024. The majority of the area contributed clay soil. In all the areas of micro-watershed, infiltration rate for clay soil is less than 5 mm/hr. Infiltration rates for all the areas was 1.72- 4.78 mm/hr. Soil infiltration during a rainstorm is closely related to a number of factors such as the intensity and kinetic energy of the rainfall, soil surface conditions and soil properties such as those related to aggregate stability. The groundwater recharge may be improved by growing plantation crop for increasing infiltration rate, construction of percolation tanks and farm ponds in the lower most of the agricultural land.