皖西大别山区土壤侵蚀空间分布特征及与地形的关系

基于修正的通用土壤流失方程和GIS空间分析方法,定量分析了皖西大别山区土壤侵蚀空间分布特征,讨论了侵蚀强度与海拔、坡度、坡向等因子的关系.基于信息熵模型评价地形因子与土壤侵蚀强度的空间相关性结果表明:(1)皖西大别山区2010年土壤侵蚀总量为1844.30×10~4t,平均侵蚀模数为1415.05t/km~2·a.区域以微度和轻度侵蚀为主,分别占总面积的52.95%和31.99%,侵蚀强度由东南至西北逐渐加剧.(2)坡度和海拔主导着区域内土壤侵蚀强度的空间分布.随着坡度和海拔增加,侵蚀强度不断加剧,强度侵蚀的面积比例增加,微度侵蚀的面积减少;在坡度15-25°区域、海拔200-500m区域的土壤侵蚀总量最大.坡向对土壤侵蚀强度的影响较小,土壤侵蚀强度在东南坡向较其它坡向略强.(3)地形因子与土壤侵蚀强度的空间相关性强弱为:坡度海拔坡向.坡度是安徽省大别山区土壤侵蚀强度的主导因子.

Spatial Characteristics of Soil Erosion and Its Relationship to Topography in Dabie Mountains of West Anhui

Based on revised universal soil loss equation (RUSLE) and GIS spatial analysis technique,this research analyzed the spatial distribution of soil erosion in Dabie Mountains of West Anhui,and explored the relationships between elevation,slope,and aspect and soil erosion intensity.The spatial correlation betweentopographic factors and erosion intensity were analyzed by using information entropy model.(1)The annual amount of soil erosion was 1844.30 × 104t,and mean soil erosive modulus was 1415.05t/km2· a in 2010.Spatially,soil erosion strengthened from southeast to northwest.Trivialand light soil erosion areas dominated soil erosion intensity,and accounting for 52.95 ％ and 31.99 ％ of total areas.(2) Elevation and slope dominated the spatial distribution of soil erosion intensity in Dabie Mountains of West Anhui.Soil erosion degree strengthened with elevation and slope increased.The area of trivial erosion decreased,and area of intensive erosion increased,along with elevation and slope increased.Soil erosion was the strongest from 200m to 500m in different elevation zones.In different slope zones,soil erosion in the 15-25° zone was the strongest.Soil erosion of southeast aspect was slightly stronger than other aspects.(3) The spatial correlation was ordered as follows:slope ＞ elevation ＞ aspect.Slope was the dominant factor of soil erosion intensity in the Dabie Mountains of West Anhui.