Rapid Analysis of Soil Erosion with Vegetation Changes in Western Ghat Hills, Maharastra, India.

The fragile ecosystem of the Western ghat hills of India has been an increasing cause of concern to environmentalists and water resources planners. The steep slopes in the western ghat along with depleted forest cover, as well as high seismicity due to Koyana dam have been major factors in soil erosion and sedimentation in river reaches. Prediction of soil erosion is a necessity if adequate provision is to be made in the design of conservation structures to offset the ill effects of sedimentation during their lifetime. In addition, increased urbanization, undesirable agricultural practices and severe deforestation in this area caused drastic changes in vegetation resulting in increased soil erosion. Rapid analysis of soil erosion using remote sensing is a valuable tool to take immediate remedial measures. Vegetation cover and slope steepness are two major factors that influence soil erosion. In this study, we have used Landsat images and digital elevation models to estimate soil erosion changes in 10 years time period (1989-1999). Results from Landsat images indicated that there was significant reduction in plant biomass over 10 years. Estimated mean annual erosion is increased from 1.8 mm in 1989 to 2.6 mm in 1999. The maximum estimated erosion rates were 8.1 and 9.6 mm/year in 1989 and 1999 respectively. The results clearly indicated severe erosion in this area and recommended ecological restoration.