Landscape Characterization using Geomorphometric Parameters for a Small Sub-Humid River Basin of the Chota Nagpur Plateau, Eastern India

River responses to endogenic perturbations and climatic attributes lead to the morphological development of basins, the quantification of whose terrain facets to decipher the ambient process-response mechanisms has long been an important aspect of geomorphological studies. The availability of newer, higher resolution datasets, however, entail that past exercises in this domain be looked at anew, in terms of the greater sensitivity and diversity of information that can now be extracted/collated. Here, we combine classical and modern morphometric methods to examine the terrain characteristics of the Kharkai River Basin in eastern India, with this basin chosen for its diversity of landforms and human activities. While traditional methods have been based on eliciting terrain information from topographical maps, we use a higher resolution Digital Elevation Model (DEM) to extract such attributes. The stream network was derived using flow-routing and flow accumulation algorithms and a net of 1 km × 1 km grids was overlain on the DEM to compute various morphometric parameters. These were combined using Principal Component Analysis to demarcate distinct physiographic/landscape entities, in conjunction with the corresponding lithological and soil attributes of the area. Multi-temporal land cover and land use layers extracted from Landsat datasets were overlain on the extracted terrain units to estimate changes in the same across different landscape types. The demarcated terrain units strongly correlated with the lithology, as expected, and this also controlled local slope and drainage development. More rugged locales had greater vegetation cover but were also threatened by deforestation due to agricultural expansion and mining.