Study on the method of length-slope factor re-scaling in the region-scaled soil erosion assessment: An example in Shaanxi Province,China
Its the only way to extract length-slope(LS) factor based on low resolution DEMs for USLE used in the studies of regional scale soil erosion modeling. But the length-slope factor value generally become small because the slope reduces and the slope length enlarges. Based on the hydrologically correct DEM of 50m and 10m resolution using AUNDEM software in Shaanxi Province with the 1:250,000 digital topographic maps and 6 locations representing varied terrain in Shaanxi Province with the 1:50,000 digital topographic maps, the derived slope and slope length from 50m resolution DEM were re-scaled to be similar to that of 10m resolution DEM using histogram matching principle. The effect of the length-slope factor of pre-post re-scaling on soil erosion intensity was evaluated and analyzed. The results show that re-scaled slope gradient becomes steep, the re-scaled slope length becomes short and LS factor value becomes increase with similar space structure and calculated results to high resolution (10m) DEM. Meanwhile, four datasets of soil erosion intensity are calculated with Chinese Soil Loss Equation (CSLE), including (a) slope and slope length unre-scaling, (b) slope re-scaling, (c) slope length re-scaling, (d)slope and slope length re-scaling. It shows that the (a) can obviously increase soil erosion intensity, the (b) can decrease soil erosion intensity, but the (c) can finally increase soil erosion intensity, which can explain the effect of slope reduction on soil erosion assessment larger than slope length enlargement. Therefore, its necessary to carry out LS factor re-scaling in application.
DEM ANUDEM slope and slope length re-scaling soil erosion assessment
Weiling Guo Qinke Yang Chunmei Wang Jun Li Lin Cheng Rui Li
Institute of Soil and Water Conservation, Chinese Academy of Sciences, Ministry of Water Resources, College of Urban and Environment, Northwest University, Xi’an, 710069, China;Institute of Soil and W College of Resources and Environment, Northwest A & F University, Yangling, Shaanxi 712100, China
国际会议
西安
英文
907-911
2010-10-11（万方平台首次上网日期，不代表论文的发表时间）