中文摘要：

为探索水库修建后对下游河流生态环境的影响,基于RVA（变化范围法）思想选取能反应建库前后下游生态环境变化的一系列指标,构建了水库下游河流生态风险评价指标体系。并在采用风险指数法与RVA法对其进行估计量化和权重确定的基础上,针对生态风险评价工作及人类对生态环境认识程度本身所具有的模糊性,将生态风险量化为5个等级标准,建立了水库下游河流生态风险的模糊综合评价模型。实例计算表明,该方法能定量给出水库下游河流生态风险综合评价结果,对水库建成后生态风险评价及管理工作具有一定的参考价值,有助于河流的可持续开发利用与生态环境的进一步改善。

英文摘要：

To explore the influence the reservoir construction exerts on the ecological environmental of reservoir downstream rivers,this paper,based on the ideology of the RVA（Range of Variability Approach）,chooses a serial of indexes which reflect the change before and after the reservoir construction to establish the ecological risk assessment index system of reservoir downstream rivers.And based on quantifying the risk index and determining the weight of each risk indicator by the risk index method and RVA,according to the fuzziness of the ecological risk assessment and the cognition of human,it quantifies the ecological risk to 5levels and then establishes the ecological risk fuzzy comprehensive evaluation model of reservoir downstream rivers for the evaluation of risk values.The case study indicates that,this method can provide the quantitative result of downstream river ecological risk comprehensive evaluation values.This evaluation method serves as a guide to the reservoir ecological risk management and evaluation work,contributing to sustainable developing and utilizing the rivers and perfecting management system of ecological environment.