基于格局和过程的流域生态系统减轻入库泥沙服务及价值——以雅砻江二滩水库为例  

Evaluation of a watershed ecosystem service for avoiding reservoir sedimentation and its economic value based on pattern and process—a case study from Ertan reservoir in Yalong river

作　　者：吴楠[1] 苏德毕力格[2] 高吉喜[3] 张晨[2] 葛菁[1] Ennaanay Driss 田美荣[2] 

机构地区：[1]安徽省环境科学研究院,安徽合肥230022 [2]中国环境科学研究院生态环境研究所,北京100012 [3]环境保护部南京环境科学研究所,江苏南京210042 [4]斯坦福大学伍兹环境研究所,美国加利福尼亚州943055020

出　　处：《中国环境科学》2011年第10期1751-1760,共10页China Environmental Science

基　　金：环保公益性行业科研专项(200709029);UNEP/GEF长江流域自然保护与洪水控制项目(GFL-2328-2740-4822.GF/3030-04-05-01)

摘　　要：基于径流泥沙的运移过程,构建了沿汇流路径,结合不同土地覆被对泥沙拦截能力系数模拟每个像元截留泥沙使其不进入水库量的模型.结合单位体积淤泥的清淤费用、水库使用年限及贴现率进行构建价值量模型,并在二滩水库的集水区进行了模型的运用.结果表明:2000～2005年,土地覆被格局的变化主要体现在雅砻江中上游草地向林地的转化和下游亲水区林地向农田和草地的转化.由此影响到2000和2005年土壤侵蚀总量变化不大,但2005年集水区向水库输沙总量有较大增加,农田也成为二滩水库最为主要的产沙源.多数被侵蚀的土壤在向二滩水库的运移过程中被各类生态系统截留,截留泥沙量的高值集中分布于二滩库区周边.林地平均截留泥沙绝对量较低,截留泥沙的能力未能得到有效发挥.集水区对于减轻进入二滩水库泥沙服务的总经济价值在2000和2005年分别达到442.2和785.8亿元.The pattern and processes of ecosystem is basis of ecosystem services＇ supply.A model was established to simulate an ecosystem service of avoiding reservoir from sedimentation and its economic value based on the process of sediment delivery in a watershed.The model included fabricating the watershed of the study reservoir.The sediment retention coefficient of different land cover types were used to simulate the spatial patterns of the annual quantity of the sediment that were prevented from entering the reservoir by the vegetation in each cell followed the flow path in watershed.The economic value of the ecosystem service in this model was determined by the marginal cost of reservoir desilting.This study took the Ertan reservoir as an example.The results showed that the pattern of land cover change was mainly performanced in grassland transforming to forestland in the upper and forestland transforming to farmland and grassland in lower Yalong River from 2000 to 2005.The total actual soil erosion was little changed in the five years.However,the total sediment yield to Ertan reservoir had the large scale increase in 2005.Farmland was the most important source in sediment yield.Most eroded soil was intercepted by different types of ecosystems in the process of sediment delivery in a watershed.The region with a higher quantity of sediment retention was around the reservoir.The absolute quantity of average sediment retention in forestland was lower,so the sediment retention ability of forestland failed to be brought into fullest play in watershed.The total value of the avoided Ertan reservoir sedimentation service in the watershed was 44.2 and 78.6 billion Yuan in the 2000 and 2005.

关 键 词：格局 流域生态系统 输沙量 截留泥沙量 经济价值 二滩水库 

分 类 号：X321[环境科学与工程—环境工程]