Soil Creeping in Weathering Crusts of Carbonate Rocks and Underground Soil Losses in Karst Mountain Areas of Southwest China

Rocky desertification is widespread over karst mountain areas, particularly underlain by pure carbonate rocks in Southwest China and has had great impacts on local social and economic development. This paper focuses on the mechanism of rocky desertification and its acceleration by human activities. Soil creeping and sliding occur intensively in the weathering crusts of carbonate rocks and at the interfaces between the crusts and the underlying bedrock. The abrupt soil-rock contact at the interfaces is caused by long-term soil creeping and sliding on the bedrock surfaces, which are often very smooth. Both surficial and underground soil losses can cause rocky desertification in this area. Underlain by pure carbonate rocks, underground pipe erosion may be the predominant process of rocky desertification because soil formation rates are usually slower than natural soil erosion rates. In general, rocky desertification is a natural, irreversible geomorphologic process for most karst mountain areas underlain by pure carbonate rocks in Southwest China. Human activities often accelerate rocky desertification. Present soil conservation measures, such as forestation and terracing, have little effect on mitigation of rocky desertification. It is a new challenge to mitigate rocky desertification in karst mountain areas underlain by pure carbonate rocks.