Mapping of Erosion Hazard in and around Kharagpur Hills, Bihar using hydrological indices

Soil is the most important gift of nature formed in hundreds/thousands of years covering the land surface but soil cover is depleting day by day due to geological and/or anthropological activities. Erosion is one of the most important geological processes in reducing the soil cover. Hence, there is a requirement to conserve the soil cover and the first thing which can be done in order to conserve the soil is the identification of vulnerable areas. Identification of vulnerable areas is of foremost importance which could be done by scientific methods. Hydrological Parameters are one of them which can be calculated using Geographic Information System. In this study, Digital Elevation Models have been processed in geographic Information System to calculate three important hydrological indices i.e., Sediment Transport Index, Topographic Wetness Index and Stream Power Index along with other parameters like Slope. Maps showing variability in Slope, Sediment Transport Index, Topographic Wetness Index and Stream Power Index have been prepared to understand the variability and the importance of each parameter in marking the vulnerable areas to erosion. With this, an Erosion Hazard Vulnerability Map of the study area (in and Around Kharagpur Hills, Munger-Jamui, Bihar) has been prepared using Weighted method of Geographic Information System. It has been found that Soil cover over the hills with Steep Slopes are more prone to erosion whereas Soil cover over the very gentle slopes or in the flat areas are least prone to erosion. Along with this it has also been found that river sediments deposited in the point bars along the banks of the river Ganges are also moderately to highly prone to erosion. The importance of spatial analyst tool of geographic information system has been utilized in delineating the vulnerable areas.