Mechanism of Payment for Ecological Services in Weigan River Basin

研究以渭干河流域为例，在初步揭示流域土地-生态服务功能价值-水三者关系的基础上，构建流域多层次、多种生态要素、多元主体间的生态补偿机制。主要内容包括：1）运用GIS分析，结合引力和场强模型计算出上游向下游流转的生态服务价值，2007年上游共溢出生态服务价值24.83亿元，向库车、沙雅和新和流转价值分别为2.81、6.42和15.6亿元；2）构建水资源边际效益模型与弹性模型，计算了2000～2006年农业灌溉用水投入与耕地生态服务价值产出之间的关系，农业用水每变化1%，生态服务功能价值变化约11.41%，而经济价值则变化约7%，上游灌溉用水的最大水量9.3′108~9.5′108m3；3）运用生态损益法、机会成本法及CVM方法，计算出上游应获得的最高补偿标准为24.83亿元，最低标准为0.24亿元，参考标准为7.1亿元；构建成本分担模型，计算下游县对上游机会成本损失的分担数额分别为库车2.11亿元，沙雅为1.82亿元，新和3.18亿元；4）运用情景模拟方法，引入Markov 链对无补偿、现有补偿和充分补偿条件下的用地类型变化进行模拟分析，发现按照参考补偿标准进行足额补偿时，既能保障上游土地利用向有利于生态环境优化的方向发展，又可提高上游居民尤其是水源涵养区的农牧民收入水平，使流域的生态系统和社会经济系统更趋和谐。This dissertation, taking the Weigan River Basin as study area, revealed relationship among land use-ecosystem service value-water, and constructed mechanism of eco-compensation in the Weigan River Basin. Research mainly focuses on four aspects: 1) Gravity model, field intensity model, buffer and overly analyses of GIS are used to calculate the scope and intensity of ecosystem service value circulation from the upstream to the downstream. Ecosystem service value that overflew from upstream to downstream reached 24.83?108Yuan in 2007, the value to Kuche 2.81?108Yuan, to Shaya 6.42?108Yuan, to Xinhe 15.6?108Yuan. 2) According to marginal benefit model, the elasticity model and input-output model, the model of agricultural irrigation water and ecosystem service functions of farmland were built. The results of calculation show that the maximum supply quantity of agricultural water is 9.3?108~9.5?108m3, and if more than the value, the water supply is invalid. The elasticity showed that if the agricultural water consumption changes 1%, the value of ecosystem service functions will change about 11.41%, and the value of economic changes about 7%. The calculation above provides evidence for making ecological compensation standard of water resources in river basin. 3) By calculating ecological profit and loss, opportunity cost and willingness to pay, the maximum standard, minimum standard and reference standard of compensation can be attained, which are 24.83?108Yuan, 0.24?108Yuan and 7.1?108Yuan. Based on the quality and quantity standards of water, cost-sharing model is built to compute the shares that counties of the lower reaches have to undertake. The results indicate that Kuche has to pay 2.11?108Yuan, Shaya, 1.82?108Yuan, and Xinhe, 3.18?108Yuan. 4) Using Scenario Analysis and Markov chain to analyze the land use change in different conditions, such as no compensation, present compensation and full compensation. We found that full compensation can not only benefit for ecological environment protection, but enhancing the income level of inhabitants, especially of farmers and herders in water source conservation area