那曲河水电梯级开发的生态价值损益比较分析

Comparative Analysis of Ecological Value Loss and Gain from Hydropower Cascade Development in Naqu River

水电开发在促进当地社会经济发展和提高人民生活质量的同时,也会对其环境造成不可避免的影响。生态环境价值损益分析在统一量纲下,将结果利用货币形式表达出来,实现水电开发对环境影响的综合评价,可为工程决策和环境保护提供依据。以那曲河2种方案的梯级水电开发对环境的影响为例,筛选并建立评价指标体系,对流域内水电开发的环境影响生态效益和生态环境成本进行了定量分析。结果表明,那曲河2种方案梯级水电开发带来的直接生态环境价值分别为1.05×108元/a和1.46×108元/a,能源替代的间接生态环境价值分别为5.13×107元/a和5.04×107元/a,而生态环境成本价值则为9.40×107元/a和9.73×107元/a。2种方案直接环境价值和生态环境成本的比值为1.1∶1和1.5∶1,说明梯级水电开发生态环境效益大于成本,且方案2优于方案1。梯级水电开发生态环境价值的评价方法还不成熟,且评价指标目前还没有统一标准,因此评价内容的完整性和准确性与实际有一定的差别,只能为水电开发建设和环境保护提供借鉴依据。

Hydropower development has an inevitable impact on local environment,while promoting socio-economic development and improving the quality of people′s lives.The loss and gain analysis of ecological environment,expressed by currency in a unified dimension,may provide a basis for engineering decision because of its general evaluation on environment.An evaluation index system is established and the benefits and costs from hydropower development are analyzed by taking the environment affected by two scenarios of cascade hydropower development in the Naqu River for an example.Results show that the direct ecological values from two scenarios of cascade hydropower in the Naqu River are 1.05×108 and 1.46×108 yuan per year and the indirect values,5.13×107 and 5.04×107 yuan per year,while the ecological environment costs are 9.40×107 and 9.73×107 yuan per year,respectively.The ratio of the direct environmental benefit to the environmental cost from the two scenarios is 1.1∶1 and 1.5∶1,respectively,which illustrates that the benefits exceed the costs and the scenario two is superior to the scenario one.The valuation methodology of eco-environmental value in the hydropower development is not yet mature and currently,there is no unified evaluation standard.So there are some differences in the completeness and accuracy of the evaluation contents,as compared with the practice.The evaluation system can only provide a reference basis for the construction of hydropower development and environmental protection.