Geomorphological Mapping and Landform Characterization of the Lower Papagni River Basin, Karnataka State, India

Abstract

Geomorphological maps serve as fundamental tools for interpreting the origin and evolution of landscapes and for assessing their influence on natural resources and environmental hazards. Landforms are natural physical features developed on the Earth’s surface through the combined influence of internal tectonic forces and external geomorphic processes such as weathering, erosion, transportation, and deposition. The study presents a geomorphological mapping and landform characterisation of the Lower Papagni River Basin, Chikkaballapura District, Karnataka, situated within the semi-arid hard rock terrain of the Peninsular Gneissic Complex. The basin exhibits a diverse assemblage of structural, denudational, and fluvial landforms developed under prolonged weathering and erosional processes typical of crystalline terrains. Geospatial techniques integrating Remote Sensing, Geographic Information Systems (GIS), and Digital Elevation Model (DEM) analysis were employed for systematic delineation of geomorphic units. Multi-temporal Landsat 8 OLI and Sentinel-2 MSI datasets, along with SRTM-DEM, were utilised to extract terrain attributes such as slope, drainage pattern, morphometric parameters, and structural controls. The analysis indicates the dominance of pediplains, accompanied by structural hills, denudational hills, pediments, inselbergs, valley fills, and lateritic surfaces, reflecting a mature geomorphic stage with extensive planation and residual uplands. The drainage network exhibits predominantly dendritic to sub-dendritic patterns, suggesting lithological homogeneity with localised structural influence. Hydrogeomorphically, pediplains and valley fill deposits constitute favourable groundwater potential zones due to thicker weathered mantles and enhanced infiltration capacity, whereas structural and denudational hills represent runoff-dominated terrains. Lineaments and fracture systems act as significant conduits for groundwater movement in the crystalline basement.