Landform classification and geomorphological mapping of the Chota Nagpur Plateau, India

Geomorphological map plays a key role to illustrate landscape evolutionary history along with the guidelines of sustainable landuse planning. The Chota Nagpur Plateau is situated in the eastern part of the Indian subcontinent and it is a storehouse of valuable rocks and minerals of Precambrian origin. Classification of geomorphological units is highly required for sustainable landuse planning and natural hazards management. So, the principal objective of this scientific study is to classify the Chota Nagpur Plateau region into micro geomorphological units by applying automated and semi-automated methods. Digital elevation model (DEM) data and satellite imageries (from United States Geological Survey) have been used to improve the precision of this map. Geomorphological mapping techniques such as terrain attributes classification, Topographical Position Index (TPI) and Slope Position Index (SPI) have been applied to extract the major geomorphological units or features. TPI values show that the maximum area comes under the valley bottom with stream (35.26%) followed by the high ridge (24.55%) whereas minimum area coverage is found in the open slope zone (0.02%). Local ridges and mid-slope ridges lie in 8.77% and 4.94% area respectively. The result has been verified through field verification techniques with the help of GPS data. This high-accuracy map should be applied for regional planning and natural hazards management. These techniques also give very good results for terrain classification as well as landforms evolution.