The study was in order to assess soil erosion at watershed scale Universal Soil Loss Equation (USLE) erosion model has been used for the study in Kotagiri Region, Nilgiris district. Erosion calculation requires huge amount of information and data, usually coming from different sources and available in different formats and scales. Therefore GIS technique has been used, which helped considerably in organizing the spatial data representing the effects of each factor affecting soil erosion. The factors that most influence soil erosion are linked to topography, vegetation type, soil properties and land use/cover. Average annual soil losses were calculated by multiplying five factors. A set of factors as identified in the USLE were studied and reviewed. These include rainfall erosivity factor (R-factor), soil erodibility factor (K-factor), slope and slope length factor (LS-factor), and vegetative cover factor (C-factor) and conservation practice factor (P-factor). Each factor which consists of a set of logically related geographic features and attributes is used as data input for analysis. The factor layers were collected from existing information and extracted from Landsat imagery.
USLE model,Nilgriris,Watershed and Topography.