Soil Infiltration Dynamics and Hydro-Physical Properties of Black Cotton Soils in a Semi-Arid Hard Rock Terrain: A Case Study from Bennihalla Basin

Understanding soil infiltration characteristics is vital for effective water resource management, especially in semi-arid regions with complex geological settings.This study investigates the infiltration dynamics of different soil types in the semi-arid hard rock terrain of the Bennihalla Basin, with a focus on identifying potential sites for artificial groundwater recharge.In contrast, red sandy mixed soils demonstrate significantly higher infiltration rates, with initial and constant values of 7.1 cm/hr and 10.5 cm/hr, respectively, attributed to their coarser texture and lower moisture retention.The infiltration rate vs. time graphs indicate that most soils experience a rapid initial infiltration followed by a gradual decrease to a constant rate.Areas with dominant silty clay textures also show higher organic matter content (1.5% to 6.5%), particularly in vegetated zones such as Dadherkoppa and Dharwad.On the other hand, regions like Mulgud and Betsur with red mixed soils display lower moisture but higher infiltration capacities.These findings highlight significant spatial variation in infiltration behavior across the basin.The infiltration study helps identify zones where rainwater can percolate efficiently into the subsurface.Areas with higher infiltration rates, wellconnected fractures, and minimal surface sealing are therefore prioritized for check dam construction, as these structures will enhance groundwater recharge and reduce surface runoff losses.Such interventions can enhance subsurface recharge, reduce surface runoff, and improve overall watershed management.