汉江流域水电梯级开发对生态环境影响评价研究

Study on eco-environmental effect assessment for cascade hydropower development in Hanjiang River basin

汉江是长江中游最大的支流,水能资源蕴藏量丰富,然而水电梯级开发与流域生态环境之间的矛盾是当前汉江流域面临的首要问题,如何评估汉江水电梯级开发造成的生态环境影响已成为学者广泛关注的问题。通过分析流域生态系统结构和功能,构建了基于PSR模型的水电梯级开发生态环境影响多层次评价指标体系,采用熵权法确定指标权重,运用专家评分法对指标进行量化,对汉江流域生态环境进行了评价。评价结果表明:随着汉江干流梯级的逐步建成,汉江生态环境影响评价综合指数总体呈现下降趋势。利用SPSS将标准化后的各个水电开发阶段的压力指数和生态环境影响评价综合指数进行拟合分析,得到以诱发地震等级、河流断面宽深比等为因素的汉江流域水电梯级开发生态环境影响预测方程。该方程可为流域水电梯级开发生态环境影响预测提供借鉴。

As the largest tributary in the middle reaches of Yangtze River, Hanjiang River is rich in water resources. The most important problem in Hanjiang River Basin is the contradiction between cascade hydropower development and ecological environ- ment. How to assess the ecological impact caused by Hanjiang River cascade hydropower development has become a widely - con- cerned issue by scholars. Through analyzing ecosystem structure and function of the river basin, a multi - level evaluation system based on PSR model for the impact of cascade hydropower development on ecological environment was constructed. The index weight was determined by the entropy method,-and the indicators were quantified by expert scoring to evaluate the ecological envi- ronment in Hanjiang River basin. The results show： with the development of Hanjiang River cascade dams, the ecological envi- ronment impact assessment index of Hanjiang River presents an overall downward trend. By using SPSS in the fitting analysis of the normalized pressure indexes in various stages of hydropower development and comprehensive impact assessment indexes of Hanjiang River ecological environment, a prediction equation of eco - environment impact with seismic induction levels and river width - depth ratio etc. as the factors was established, which can provide a reference for the prediction of eco - environment im- pact caused by cascade hydropower development.