[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.%研究岩溶区土壤侵蚀评价方法,既可以对岩溶区水土流失状况有深入了解,也可以为水土流失治理和评价提供依据.在贵州关岭、云南罗平、云南峨山3个县岩溶区,抽样选取44个小流域进行野外考察,收集土壤侵蚀因子的相关信息,分别通过因子分级判断侵蚀强度方法(因子法)和土壤侵蚀模型CSLE计算土壤侵蚀模数,再判断侵蚀强度的方法(模型法),对研究区水土流失面积和土壤侵蚀强度进行对比分析.同时对比这2种方法在土壤侵蚀分类分级标准SL190-2007和SL461-2009下的差异,并通过分析不同土地利用类型下水土流失面积占比的差异,分析各种评价方法的优劣.结果表明:在SL190-2007分级标准下,模型法和因子法得到的单元平均水蚀比例差异较大,分别为35.98％和72.40％;在SL461-2009分级标准下,模型法和因子法得到的水蚀比例有较好的匹配,分别为70.11％和69.31％.在SL190-2007标准下,模型法侵蚀量标准偏高,不适用于岩溶区;由于考虑了基岩裸露率的影响,在SL461-2009标准下,因子法对林、草地水蚀比例的评价相对更合理;在SL461-2009标准下,模型法由于综合考虑了降雨、土壤、地形、植被覆盖与生物措施、工程措施和耕作措施的影响,且能定量模拟土壤侵蚀模数,是最合理的方法.但由于目前模型法中土壤可蚀性因子对基岩裸露这一岩溶区典型现象反映不够,导致评价结果中林草地水蚀比例偏高,下一步应开展基岩裸露率的调查、在模型法中加入基岩裸露率的影响,提高模型法的精度.
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