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Soil erosion dynamics of Zhifanggou Watershed during the past 70 years |
Pang Guowei1,2, Xie Hongxia1,3, Li Rui1, Yang Qinke4 |
1.Institute of Soil and Water Conservation, CAS&MWR, 712100, Yangling,Shaanxi; 2. Graduate School of the Chinese Academy of Science,100049, Beijing; 3.Resource and Environment College of Hunan Agriculture University, 410128, Changsha;4. Urban and Environment College of Northwest University, 710127, Xi’an:China |
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Abstract In order to explore the dynamic change of soil erosion in Loess Hilly-gully Area of Loess Plateau, this paper, taking Zhifanggou Watershed as a case study, evaluated the soil erosion change from 1938 to 2010. Combined with GIS technique, the revised universal soil loss equation (RUSLE) was used to evaluate spatial and temporal change of soil erosion. The results showed that: 1) The soil erosion modulus increased significantly from 7584.39t/(km2·a) in 1938 to 46392.56t/(km2·a) in 1958, while it decreased to 5150.80t/(km2·a) in 2010. 2) The area below moderate erosion account for 52.99% of the whole area in 1938. 3) During the periods from 1958 to 1978, severe erosion account for a major part of the whole area, which was 67.05%, and the most severe erosion happened in 1958, which account for 78.61% of the whole area. 4) Soil erosion intensity decreased slightly during the period from 1978 to 1998, the area with slight erosion accounted for 29.27% of the whole area; the area increased to 3.85km2 since 1999, and area severe erosion only account for 8.96% of the watershed area. As the continuous ecological management over the past 30 years, the eco-environment in Zhifanggou Watershed was improved, but soil erosion in steep slope and gullies are still the key problems in the future conservation.
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Received: 10 October 2011
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