Soil Erosion and Sediment Disaster in Nepal-A Review

Nepal is very prone to soil erosion and is susceptible to 'sediment disasters mainly caused by slope failure, landslides, debris flows and bank erosion. Fertility of the soil or productivity of the land is deteriorating due to accelerated surface soil erosion. At the same time, sediment disasters annually destroy or damage residential areas, agricultural land with crops and development infrastructures. Magnitude and effects of these geomorphic processes are very high due to the fragile geology, steeply sloping rugged mountain topography, anomalous climatic conditions and human activities. Urgent need of accelerated erosion control and prevention of potential sediment disasters is realised and various soil conservation measures and watershed management programs have been implemented for this purpose. But, the problems are still critical. Soil erosion or sediment disasters due to natural processes are likely to continue into the future also but, human contribution in accelerating these processes can be minimized. Very limited research works, lack of economically feasible appropriate technology, inappropriate land use and insufficient resources are main problems implementing erosion control and sediment disaster prevention counter measures. International cooperation is expected in the research, appropriate technology transfer and human resource development to develop Nepal as a less hazardous country in the future.