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| Spatial distribution analysis of soil erosion in the Three Gorges Reservoir Area |
| Wu Changguang1,2, Lü Huali1, Zhou Zhixiang1, Xiao Wenfa3, Wang Pengcheng1,3, Wang Tao1 |
| 1. College of Horticulture and Forestry, Huazhong Agricultural University, 430070, Wuhan; 2. Research Institute of Subtropical Forestry, Chinese Academy of Forestry Sciences, 311400, Fuyang, Zhejiang; 3. Research Institute of Forest Ecology Environment and Protection, Chinese Academy of Forestry Sciences, 100091, Beijing: China |
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Abstract In this paper, RUSLE factors algorithms were improved based on environmental characteristics and data availability in the Three Gorges Reservoir Area. Based on GIS technology the improved algorithms were used to evaluate the risk and spatial distribution of soil erosion. The results showed that the annual soil erosion amount and the mean soil erosion modulus in the Three Gorges Reservoir Area were 18359.43×104t/a and 31.85t/(hm2·a), respectively. The area suffering soil erosion accounted for 66.97% of the reservoir area. There was no direct linear relationship between soil erosion intensity and the altitudinal gradient in Three Gorges Reservoir Area. The area with from moderate to severe erosion intensity mainly distributed in 500-1500m elevation zone, which may resulted from the impact of intensive human activities in last decades. The soil erosion intensity was significantly positively correlated with slop gradient. When slope gradient was larger than 15 degree, the frequency of more than moderate erosion increased significantly, The slope area of larger than 15 degree accounted for 53.74% of the reservoir area, but contributed 89.06% of the total soil loss. Soil erosion intensity varied with slope aspects in a trend of semi-shady slopes＞shady slopes＞semi-sunny slopes＞sunny slopes. The amount of soil erosion on shady slopes was slightly higher than that on sunny slopes, accounted for 56.50% of total erosion amount. The results indicated that soil erosion mainly occurred in 500 to 1500m elevation zone, slope gradient larger than 15 degree, and shady slopes, which are also the key regions of soil and water loss prevention in Three Gorges Reservoir Area.
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Received: 07 October 2011
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