TR(BR)-9/96-97 : Wind erosion and lake sedimentation in desert area

Abstract

Soil erosion from the nearby catchment area of the lakes and its subsequent sedimentation in the lakes, is one of the major hydrologic problems of our lakes. The fury of wind forces is considerable in the desert area to make substantial wind erosion. As per the estimate made by the National Commission of Agriculture, about 32 million hectare land in India is affected by wind erosion which includes 23.5 million hectares of The Great Indian Desert in the arid zone of north western India. About 19 million hectare of the desert area is subjected to the soil erosion by wind. The eroded soil from the desert area poses major menace to the lakes and other water bodies in the form of sand drifts, reactivation of the sand dunes in the desert area of Rajasthan. Sand dunes are very susceptible to wind erosion and fragile. Man made activities often reactivate the stabilized dunes. The annual soil loss is high and ranges between between 1500 t/ha and 2500 t/ha.

In this report, various processes and mechanism of wind erosion, factors which contribute to the increase or decrease of wind erosion in a desert area have been discussed with reference to Indian desert. The method of estimation of soil loss in a desert area due to wind as suggested by Woodruff and Siddoway in the line of universal soil loss equation is also explained. The method is comprehensive and is based on the relationship between potential soil loss from field and eleven primary field and climatic factors influencing erosion. However, these eleven factors could be conveniently reduced to five equivalent variable depending on certain field condition.