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| Current status and comprehensive control strategies of soil erosion for the upper Yangtze and other rivers in the Southwestern China |
| Cui Peng,Wang Daojie,Fan Jianrong,Wang Yukuan,He Xiubin,Zhu Bo,Wei Fangqiang,Wang Genxu |
| Key Laboratory of Mountain Hazards and Surface Process,CAS;Institute of Mountain Hazards and Environment,CAS: 610041,Chengdu,China |
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Abstract There are variety of soil erosion in the upper reaches of Yangtze and other rivers in the Southwest of China,located in the transition zone from2the Tibet-Qinghai Plateau to the moderate mountains and hills.Remote sensing data of 2000 indicate that the eroded area of 1 324 100 km22,54.34% of the total area of the region,among which 700 000 km22 are of moderate and intense erosion;281 200 km22 are of extreme erosion.The main agents of erosive action include freeze-thaw erosion,water erosion,and wind erosion,which covers area 769 200 km22,518 000 km22,and 36 900 km22 respectively.Soil erosion is widely distributed on the cultivated slopes;debris flows and landslides are the most frequent disasters,threatening structures and public properties;reservoirs are polluted by non-point contaminant transported with the process of soil and water losses;and grasslands are severely degraded in the source areas of the stream2systems and the functions of ecologic barrier are largely weakened;rocky desertification is extensively expanded as to cause the soil loss and local poverty.In addition,large-scale constructions are enhancing the soil erosion.To prevent from2the further erosion,the following strategies are proposed: terracing the slopes and constructing slope water systems;controlling gully erosion and debris flows and landslides;preventing water pollution by the integrated countermeasures of soil and water conservation;improving cultivation and protecting pasture and ecology;preventing rocky desertification and sandification;emergently preserving soil resources;reinforcing prevention and censorship in soil and water conservation.
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Received: 10 December 2007
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