安徽省土壤侵蚀空间分布及其与环境因子的关系

基于USLE和GIS空间分析技术,对安徽省土壤侵蚀空间分布进行了定量研究,分析了土壤侵蚀空间分布与地形、土壤类型、土地利用方式的关系。结果表明:安徽省2002年平均土壤侵蚀模数为249.5t/km²·a,土壤侵蚀总量为33599148t/a。土壤侵蚀空间分布呈块状分布特征。淮北平原地区土壤侵蚀较弱,皖南丘陵山区和皖西大别山区土壤侵蚀较严重。在不同高程带上,200~500m高程带土壤侵蚀最强;不同坡度等级中,15°~25°坡度上的土壤侵蚀最强,>35°坡地上则较弱;不同坡向中,东南坡土壤侵蚀最强,其次是东坡;不同用地类型的土壤侵蚀程度不同,草地的土壤侵蚀最为严重,其次是林地;在各种土壤类型中,紫色土和黄褐土的土壤侵蚀最为突出,棕壤的土壤侵蚀微弱。

Spatial distribution of soil erosion and its relationship to environment factors in Anhui Province

Based on universal soil loss equation and GIS spatial analysis technique, the authors studied the spatial distribution of soil erosion in Anhui Province. The relationships between soil erosion and terrain, soil types, land uses were investigated in this paper.The results showed that the mean soil erosive modulus is 249.5 t/km².a and the total amount of soil erosion is 33599148 t/a in 2002. Minute erosion area is predominant, occupying 118391 km² or 87.9% of the region.Moderate erosion occupies the largest amount (13533009 t/a, 40.3% of the region). Intense erosion area is small, occupying 612 km² or 0.5% of the total area; Intense erosion amount is 104018 t/a, or 0.3% of the total amount. Spatially, soil erosion is featured by obvious block distribution. The soil erosion is weaker in Huaibei Plain, but stronger in hilly mountain of southern Anhui and Dabie Mountain of western Anhui. Soil erosion is the strongest from 200 m to 500 m in different elevation zones in the study area. In the case of different slope gradients, soil erosion at 15°-25° is the strongest and that >35° is the weakest. In different aspects, soil erosion in the southeast is the strongest, but soil erosion in the east is intermediate. The strongest erosion occurs in grassland soil of different land use types, followed by forestland soil; Erosions in purple soil and yellow-brown soil are most prominent, but erosion in brown soil is the weakest. As a whole, the results can help recognize spatial distribution pattern of regional soil erosion and provide scientific basis for soil and water conservation and sustainable land use.