山区地形因子尺度依赖性及其对水土流失评价的影响研究--以江西省崇义县为例  

Scale-Dependence of Mountain Topographic Factors and Its Impact on Soil and Water Loss Evaluation

作　　者：廖元群 廖富强[1] 万小星 齐述华[1] LIAO Yuanqun;LIAO Fuqiang;WAN Xiaoxing(Key Laboratory of Poyang Lake Wetland and Watershed Research Ministry of Education/School of Geographic and Environment,Jiangxi Normal University,Nanchang,Jiangxi 330022,China;Jiangxi Provincial Water Administration Supervision Team,Nanchang,Jiangxi 330009,China)

机构地区：[1]江西师范大学鄱阳湖湿地与流域研究教育部重点实验室/地理与环境学院,江西南昌330022 [2]江西省水政监察总队,江西南昌330009

出　　处：《中国水土保持》2021年第10期51-55,M0003,共6页Soil and Water Conservation in China

基　　金：国家自然科学基金项目(41867012);江西省水利厅科技项目(201922ZDKT08,202124ZDKT25)。

摘　　要：坡长因子(L)和坡度因子(S)是CSLE模型等区域土壤侵蚀模型中的重要因子。利用不同比例尺地形数据计算的地形因子存在较大的差异,从而对水土流失评价结果产生影响。以山地特征明显的崇义县为例,利用1∶1万、1∶5万和ASTER GDEM 30 m空间分辨率的地形数据分别计算L、S和土壤侵蚀模数,探讨山区条件下地形因子的尺度依赖性及其对水土流失评价的影响,结果表明:①地形因子具有明显的地形数据尺度依赖性。从地形因子平均值来看,L因子1∶1万>1∶5万>ASTER,S因子1∶5万>ASTER>1∶1万。从地形因子离差系数来看,L因子ASTER>1∶5万>1∶1万,S因子1∶1万>ASTER>1∶5万。②从L因子空间分布范围看,在1.0~1.5和≥2.5分级范围内的面积占比均表现为1∶5万>ASTER>1∶1万,在1.5~2.0分级范围内的面积占比1∶1万>1∶5万>ASTER。从S因子空间分布范围看,1∶1万地形数据低值区的面积占比高,1∶5万地形数据高值区的面积占比高,ASTER地形数据在各分级范围内分布较为均匀。③基于不同尺度的地形数据,以CSLE模型计算的水土流失面积差异明显,表现为1∶5万>ASTER>1∶1万。Slope length factor(L)and slope factor(S)are important factors in regional soil erosion models.The terrain factors calculated by using terrain data of different scales are quite different,which affects the evaluation of soil erosion.Taking Chongyi county with obvious mountain features as an example,using topographic data with a spatial resolution of 1∶10000,1∶50000 and ASTER GDEM 30 m to calculate L,S and soil erosion modulus respectively,the paper discussed the scale-dependence of topographic factors in mountainous conditions and its influence on the evaluation of soil erosion.The outcomes show that a)topographic factors have obvious scale-dependence of topographic data.From the average value of topographic factors,L value of 1∶10000>1∶50000>LASTER,S value of 1∶50000>SASTER>1∶10000.From the perspective of the dispersion coefficient of the terrain factor,L value of ASTER>1∶50000>1∶10000 and S value of 1∶10000>SASTER>1∶50000;b)from the spatial distribution range of L factor,the proportion of the area within the classification range of 1.0≤L<1.5 and L≥2.5 are 1∶50000>ASTER>1∶10000 and within the classification range of 1.5≤L<2.0 is 1∶10000>ASTER>1∶50000.From the spatial distribution range of slope factor,S value of 1∶10000 low-value areas account for a high proportion,while S value of 1∶50000 is a high-value zone with a high proportion.SASTER distributes more evenly within each classification and;c)based on topographic data of different scales,the area of soil erosion calculated by the CSLE model has obvious differences,which is expressed as 1∶50000>ASTER>1∶10000.

关 键 词：坡长 坡度 土壤侵蚀 CSLE 崇义县 

分 类 号：S157[农业科学—土壤学]