Assessment of Soil Erodibility by using Geographic Information System

Abstract

Deforestation and soil erosion are the uppermost environmental problems faced by the Kundahpalam watershed in Nilgiris hills. In this study, the area vulnerable to soil erosion associated with the soil inbuilt properties under different land use of Kundahpalam watershed were studied. Erosion modeling was performed using remote sensing and Geographic Information System (GIS) to achieve the best watershed management procedure for the study area. The Soil Erosion Index (SEI) was estimated with the dispersion ratio analyzed from soil properties of the study area. The hydraulic conductivity varied from 2.39 cm/h to 0.01 cm/h in the study area. Loam soil had the highest rate of hydraulic conductivity (2.395 cm/h). The clay soil had the lowest rate of hydraulic conductivity (0.01 cm/h). The water holding capacity varied from 43.54% to 56.39%. The clay loam had highest water holding capacity and loam had low water holding capacity in the study area. The dispersion ratio of the dense forest was found to be low (2.83). The built up land (3.91) and plantation land (3.35) have high dispersion ratio. From the results it is seen that, the erosion index of the built up land was low (2.12) because of hard terrain surface. The land without scrub (3.1) and plantation land (2.8) had high erosion index and these changes were attributed due to the soil properties. Based on the Middleton principle the soil present in the study area was found to be highly erodible in nature with respect to all land uses.