Author(s):

GN Gurjar and Sanjay Swami

Abstract: Climate change also impacts two among principal processes of desertification–erosion and salinization. Soil erosion hazard depends on climatic erosivity, soil erodibility, and land and crop management practices. Climate change can impact all of these parameters and greatly accentuate the erosion hazard. Increase in frequency and intensity of extreme events would enhance rainfall intensity and its kinetic energy, wind velocity and its erosivity, and run-off velocity and its shearing and sediment carrying capacity. Furthermore, erosivity of wind-driven rain and that of shallow overland flow impacted by raindrops is more than that of a rain without wind and of a laminar overland flow. Soil erodibility increases with decrease in aggregation and reduction in aggregate strength caused by increase in slaking due to reduction in SOC concentration. Progressive desertification of the dryland tropics may reduce already low amount of SOC stored in these soils. Furthermore, desertification may also alter the emission of GHGs from these ecologically sensitive and fragile ecosystems. Thus, warming induced decline in SOC pool and aggregation, combined with increase in land conversion to meet the growing human demands, may severely accelerate soil erosion and desertification hazard. Wind erosion hazard, one of the major degradation processes in drylands.

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