【作者】 秦伟； 朱清科； 张岩； 吴宗凯； 蔡德光；

【Author】 Qin Wei~1,Zhu Qingke~1,Zhang Yan~1, Wu Zongkai~2,Cai Deguang~3 (1 Key Laboratory of Soil and Water Conservation & Desertification Combating,Ministry of Education, College of Soil and Water Conservation,Beijing Forestry University,Beijing,100083,China; 2 Wuqi Office of Returning Cropland to Fores,Wuqi County,Shannxi Province,717600,China; 3 Forestry Bureau of Wuqi County,Wuqi County,Shannxi Province,717600,China.)

【机构】 水土保持与荒漠化防治教育部重点实验室北京林业大学水土保持学院； 陕西省吴起县退耕还林办公室； 陕西省吴起县林业局；

【摘要】 土壤保育是退耕还林工程最主要和最直接的生态效益,准确核算退耕还林工程的土壤保育价值能够为评价生态建设成效和建立森林生态补偿机制提供重要依据。提出考虑土地覆盖汇流影响的改进坡长因子,利用ARCGIS和RUSLE评估流域在退耕前后的土壤侵蚀强度变化,采用RS和GIS监测退耕还林工程的具体实施方式及其面积,并在此基础上采用机会成本法和替代价格法评估退耕还林工程土壤保育价值的方法。同时,在全国退耕还林工程典型地区吴起县境内,选取四面窑沟流域为研究对象,应用该方法对流域退耕还林工程的土壤保育价值进行了评估。结果表明,1997～2004年,流域内实际开展退耕还林工程1895.8公顷,其中,荒山造林369.99公顷、退耕还林357.48公顷、退耕还草901.72公顷、人工封育266.61公顷;退耕前(1997年)后(2004年)流域土壤侵蚀模数减少了4644.04吨/(平方公里·年),侵蚀强度由极强度降低为中度;退耕还林工程每年产生土壤保育价值1324.3万元,其中,减少土壤侵蚀效益8.11万元、减少肥力流失效益1180.22万元、减少泥沙淤积效益124.45万元、培育土壤效益11.52万元。更多还原

【Abstract】 Soil conversation is the uppermost and direct ecological benefit of the land conversion project.Assessing soil conversation value accurately can provide an important reference for assessing effect judgment and founding ecological compensation mechanism of the land conversion project.One evaluation method for soil conversation value of the land conversion project was presented.This method calculates using method of opportunity cost and replacement price,based on mending L factor of the revised universal soil loss equation (RUSLE) that considers the effect of land cover for erosion,assessing the dynamic changes of soil erosion due to the land conversion project by using RUSLE and ARCGIS, and monitoring the form and area of the land conversion project by using RS and GIS. Then,the Simianyaogou watershed of Wuqi County,a demonstration area of the land conversion project in China,was chosen as a study case and the soil conversation value of the land conversion project in this watershed was calculated using the method.The results showed that in period from 1997 to 2004,the total area of the land conversion project was 1895.8 hm~2,which forestation on wasteland was 369.99 hm~2,conversion of cropland to forestland was 357.48 hm~2,conversion of cropland to grassland was 901.72 hm~2 and exclusion measure was 266.61 hm~2.The annual modulus of soil erosion reduced by 4644.04 t/(km~2·a).The intensity of soil erosion fell from serious grade into moderate grade.The annual soil conversation value of the land conversion project was up to 13.24 million yuan,which 0.08 million yuan for reducing soil loss,11.8 million yuan for reducing fertility loss,1.24 million yuan for reducing sediment deposition and 0.12 million yuan for increasing soil nutrient.更多还原