CSLE模型应用中不同抽样密度和推算方法的比较  

Comparison of different sampling densities and extrapolation methods based on CSLE model

作　　者：邹丛荣 齐斐[2] 张庆红[2] 刘霞[1] 张荣华[2] 黎家作[3] 董书宝 姚孝友[3] 

机构地区：[1]南京林业大学林学院江苏省水土保持与生态修复重点实验室,南方现代林业协同创新中心,南京210037 [2]山东省土壤侵蚀与生态修复重点实验室,山东农业大学林学院,山东泰安271018 [3]淮河水利委员会淮河流域水土保持监测中心站,安徽蚌埠233001 [4]山东省临沂市水土保持委员会办公室,山东临沂276000

出　　处：《中国水土保持科学》2016年第3期130-138,共9页Science of Soil and Water Conservation

基　　金：水利部“全国水土流失动态监测与公告项目-沂蒙山国家级重点治理区水土流失动态监测”(HWSBJ2012001);江苏高校优势学科建设工程资助项目;南京林业大学高层次人才科研基金

摘　　要：为探讨CSLE模型应用中,不同抽样密度和推算方法对估算县域尺度土壤侵蚀的影响,确定县域尺度既能保证精度,又能减轻外业工作量的适宜抽样密度和土壤侵蚀推算方法。以沂蒙山区蒙阴县为对象,通过对比在1%和4%2种野外调查单元的抽样密度下,分别采用单元直接外推法、单元插值外推法和栅格计算法估算土壤侵蚀状况,分析其差异性。结果表明：（1）单元直接外推法、单元插值外推法受抽样密度影响较大,在1%和4%抽样密度下,土壤侵蚀面积比相差8.82%和7.96%,相对差异达19.05%和17.43%;而栅格计算法,受抽样密度的影响较小,土壤侵蚀面积比相差3.13%,相对差异9.27%。（2）同一抽样密度下,单元直接外推法和单元插值外推法的估算结果相近,但与栅格计算法的结果差异较大,土壤侵蚀面积比相差11.77%～18.12%,相对差异34.72%～48.93%。因此,在应用CSLE模型开展沂蒙山区县域尺度土壤侵蚀调查工作时,综合考虑精度和工作量,若以高分卫片为基础,宜采用1%抽样密度和栅格计算法;否则,建议采用4%抽样密度基础上的单元插值外推法。[ Background ] As we all know, soil erosion is considered to be the most common environmental problem in the world influenced by multi-factors in multi-levels and multi-scales. Conducting regular survey on regional soil erosion condition plays an important role in evaluating the effectiveness of control measures. In China, the stratified sampling with unequal probability and the model method were firstly utilized to investigate national soil erosion conditions from 2010 to 2012. The CSLE model and the extrapolation method based on investigation units were mainly utilized in the water erosion regions. The sampling densities of investigation units were 1% for general and 0.25% for plain areas and deep mountains. It is important to understand how different sampling densities and estimation methods based on CSLE model impact on the soil erosion survey and evaluation at the county scale. [ Methods] In consideration of the study area, stratified sampling method, the unique situation of soil erosion, and the workload in field investigation of soil erosion, Mengyin County located in Yimeng mountain area was taken as an example. Based on SPOT 6 image and the topographic map at 1 ： 10 000 scale, two sampling densities with 1% and 4% , and three extrapolation methods of direct extrapolation on sampling units, Kriging extrapolation on sampling units and grid estimation were adopted to calculate the amount of soil erosion at the county scale. Then the influence of different sampling densities and extrapolation methods were explored by contrasting the results of three methods on different sampling densities respectively. [ Results] 1） Direct extrapolation and Kriging extrapolation methods were more affected by the sampling densities. The discrepancy percentage of soil erosion area calculated by two methods were 8.82% under 1% sample density and 7.96% under 4% sample density, and the relative discrepancy were 19.05% and 17.43% respectively. But grid estimation method was less affected by the sampling density. The discrepanc

关 键 词：CSLE模型 土壤侵蚀 县域 抽样密度 单元直接外推法 单元插值外推法 栅格计算法 

分 类 号：S157.1[农业科学—土壤学]