WATERSHED MODELING USING REMOTE SENSING AND GIS

Abstract

The Wadsa-Chincholi watershed situated in the Bhandara , Chandrapur, Gondia , Nagpur district of Maharashtra, which is a part of Godavari river basin, was selected for the present study. The total area of the Wadsa-Chincholi watershed is 14690.43 km2. It was divided into 50 m x50 m, 100 x 100 m, 200 m x 200 m grid cells and the average annual sediment yields were estimated at the outlet of watershed. Remote Sensing (RS) technology provides the vital spatial and temporal information on some of these parameters. A recent and emerging technology represented by Geographic Information System (GIS) was used as the tool to generate, manipulate and spatially organize disparate data for sediment yield modeling. Average annual sediment yield data on grid basis was estimated using Morgan-Morgan and Finney (MMF) model and the Universal Soil Loss Equation (USLE). Based on eight years daily rainfall data, the estimated maximum and minimum values of kinetic energy were found to be 47452.82 and 25298.86 J m2 for the year 2007and 2004 respectively. The DEM was used to generate slope map. Other inputs of the model closely related to the land use/land cover were successfully derived from remotely sensed data and the modeling part was carried out in GIS environment. Further, the sediment yields estimated by both the models were compared with observed data. The estimated average annual sediment yield from MMF model was found to be 11.17 t ha ' yr . The estimated average annual sediment yield from USLE model with 50 m x50 m, 100 mx 100 m and 200 mx 200 m grid cell size was found to be 63.80 t ha-1yf ', 18.83 t ha lyr 1 and 3.67 t ha lyr 1 respectively. The estimated sediment yields in 200 mx 200 m grid size from the observed value is satisfactory matching. Hence, the results of USLE model at 200 mx 200 m grid size can be applied for spatial sediment yield estimation from the Wadsa-Chincholi watershed.