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| Soil erosion amount and sediment delivery ratio in the hilly purple soil region in the upper reaches of Yangtze River:A case study in the Fujiang River Basin |
| Jing Ke1,2,Jiao Juying1,Li Linyu1 |
| 1.Institute of Soil and Water Conservation,CAS & MWR,712100,Yangling,Shaanxi;2.Institute of Geographic Sciences and Natural Resources Research,CAS,100101,Beijing: China |
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Abstract Based on the analysis of the controlled area of hydrological stations,morphologic landscape and land use types in the Fujiang River Basin,the soil erosion amount of non-irrigated slope land,non-irrigated steep slope land,forest land,open forest land,grassland,shrub land and bare land were calculated.The annual erosion amount of the Fujiang River Basin was 2.46×107t/a,and annual erosion modulus was 813.9t/(km2·a).The annual erosion modulus in mountainous area in the upper reaches was more than 1000t/(km2·a),and in the hilly purple soil area was 500-800t/(km2·a).The average sediment delivery ratio of the Fujiang River Basin was 0.83,while in the upper reaches was 0.90 and in the hilly area in the middle and lower reaches ranged from 0.30 to 0.80.However,there was 1.44×106t/a sediment deposited in the alluvial and diluvial fan area.The sediment delivery ratio is not correlative with the river basin area,because which is not a influence factor but a units of measurement.
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Received: 25 December 2009
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