Soil Erosion Protection on Hilly Regions Using Plant Roots: An Experimental Insight

Soil erosion is a major challenge, especially in hilly areas and countries. This study presents the results of erosion control in Nilgiris area, one of the hilly regions in India located at Western Ghats of Tamilnadu. This area experiences gully erosion that causes slope instability. In this study, an attempt was made to investigate the effect of rainfall in causing gully soil erosion in this landslide prone area, while considering factors such as varying soil density, slope angle and rainfall intensity. The study also investigated the remediation of gully erosion using vetiver, a soil bioengineering approach. A soil simulator filled with the landslide-prone soil with and without the plant roots was used at different slopes. The rate of soil erosion was studied. Soil samples were collected from the simulator and tested for its engineering properties. Results obtained showed that the slope angle has an effect on soil erosion and erosion varies inversely with density. Pore water pressure generation during rainfall creates instability among the topsoil surface, which becomes susceptible to soil erosion. HydroCAD was used in modelling the runoff over the soil surface. Soil erosion was found to occur with an increase in velocity of rainwater, which erodes the top fertile soil and triggers sheet erosion. Generally, the vetiver root was found to be efficient for the minimization of gully erosion in the Nilgiris district