中国水土保持科学2018，Vol.16Issue(2)：17-23,7.DOI:10.16843/j.sswc.2018.02.003
岩溶区土壤侵蚀强度评价方法
Methods for assessing soil erosion intensity in karst regions
摘要
Abstract
[Background] Stony desertification in karst areas demonstrates the consequence of serious soil erosion,however,the research on the comprehensive evaluation of soil erosion in rocky desertification area is deficient.[Methods] Information on soil erosion factors for 44 primary sample units (small watersheds) in three counties from karst regions,Guanling (Guizhou province),Luoping and E'shan (Yunnan province) was collected by field investigation and remote sensing interpretation.Soil erosion area and intensity were assessed by the factor scoring method and model-based method.In factor scoring method,erosion factors (e.g.rainfall erosivity,soil erodibility and slope) were classified into discrete classes and scores were given to classes based on expert experiences.In model-based method,Chinese Soil Loss Equation (CLSE) was first used to calculate the soil erosion modulus,and the erosion intensity was classified based on the amount of modulus.Factor scoring and model-based methods under two different classification standards (SL190-2007 and SL461-2009) were compared.[Results] Average soil erosion area ratios by the model-based method and factor scoring method in SL190-2007 showed an obvious difference (35.98％ and 72.40％,respectively) and those by two methods in SL461-2009 were similar (70.11％ and 69.31％,respectively).When it turned to the erosion intensity,the model-based method in SL190-2007 and the factor scoring method in SL461-2009 mainly generated the slight erosion intensity,followed by the moderate,high,severe and extreme erosion intensity;whereas the factor scoring method in SL190-2007 were dominated by the moderate erosion intensity.The slight and moderate erosion intensity in model-based method from SL461-2009 dominated and occupied the similar proportion.Farmland was the largest source of erosion area in both methods and both standards.The erosion area ratio in the forest,and grassland was relatively lower by the model-based method in SL190-2007 and the factor scoring method in SL461-2009,whereas that was relatively higher by the factor scoring method from SL190-2007 and the model-based method from SL461-2009.[Conclusions] The model-based method in SL190-2007 is not suitable for the karst regions.The factor scoring method in SL461-2009 is more reasonable comparing with the model-based method in SL190-2007 by taking the influence of bare rocky ratio into consideration.Theoretically,the model-based method in SL461-2009 is the most reasonable by considering the effect of seven natural and human related soil erosion factors,including rainfall,soil,slope degree,slope length,vegetation and biological measures,engineering measures and tillage measures.However,the soil erodibility factor in the model-based method does not reflect the typical phenomenon of exposed bedrock in karst regions at present,resulting in the unreasonable high erosion ratio in the forest and grassland.Investigation of exposed bedrock should be carried out in the next step,and taken into consideration in the model-based method for further improving the efficiency of model-based method in karst regions.关键词
岩溶区/土壤侵蚀/评价/CSLE/因子打分Key words
karst regions/soil erosion/assessment/CSLE/factor scoring分类
农业科技引用本文复制引用
李依珊,尹斌,谢云,殷水清,刘雨鑫,章文波,殷兵,杨扬,段兴武..岩溶区土壤侵蚀强度评价方法[J].中国水土保持科学,2018,16(2):17-23,7.基金项目
全国水土流失动态监测与公告项目“不同侵蚀类型区典型小流域水土流失动态监测”(1261421610273) （1261421610273）
