摘要
通过提取江西省兴国县潋水河流域10m、25m、50m和100m四种分辨率数字高程模型（DEM，DigitalElevationModel）的坡度、坡长因子，在GIS数字地形分析和数理分析等方法支持下，研究不同分辨率DEM计算坡度坡长组合因子（Ls）的精度差异。结果表明：（1）基于4种分辨率DEM提取的坡度结果存在明显差异，随分辨率的降低，坡度整体变缓，DEM精度越低，对地形的概括作用越大，100m分辨率DEM平均坡度降为10m分辨率DEM平均坡度的45．04％。（2）流域坡长以0～80m的短坡为主，随着分辨率的降低，地面坡长明显整体延伸。（3）不同分辨率DEM计算的Ls因子平均值变化范围为6．10—7．10，坡度和坡长的组合消弱了单一坡度和坡长的影响，随着地形起伏程度增大，在Ls因子计算过程中，坡度的主导作用越来越弱，坡长的主导作用越来越强。
Gradients and lengths of the slopes in the Lianshui River Basin,Xingguo County,Jiangxi Province were extracted using DEMs different in resolution,i, e. lOm,25m,50m and lOOm,and analyzed for difference in accuracy differ- ence between the DEMs in calculating the combined gradient and length,using the GIS digital terrain analysis method and the mathematical analysis method. Results show that 1 ） significant differences exist between slope gradients obtained by DEMs different in resolution,indicating that the gradient decreases with declining resolution and that the lower the accura- cy,the greater the generalized effect on terrain information; and that the mean slope gradient obtained by DEM 100m in resolution is only 45.04% of that by DEM 10m in resolution;. 2） the slopes in the valley vary in length mainly in the range of 0 ~ 80m and their lengths elongate with declining resolution; and 3 ） the mean LS factor values obtained by the DEMs regardless of resolution vary in the range from 6. 10 to 7.10 ; the combination of slope gradient and slope length fac- tors reduces the effects of single slope gradient or single slope length factor; and as the topographic fluctuation increases in extent,the dominating role in LS factor shifts from slope gradient to slope length.
出处
《土壤学报》
CAS
CSCD
北大核心
2014年第3期482-489,共8页
Acta Pedologica Sinica
基金
国家科技支撑计划项目(2011BAD31B04-2)
水利部长江委重点项目(花岗岩地区马尾松林地水土流失规律试验研究)
中国科学院战略性先导科技专项(122011151432016)资助
关键词
DEM
地形分析
地形因子
坡度
坡长
Terrain analysis
Topographic factors
Slope gradient
Slope length
