水利水电建设中河流生态用水理论与方法研究

国内外研究表明，除了水质，生态用水也是维持生态系统健康发展的重要因素。因此，在水资源配置中保证一定量的生态用水是保护生态环境的重要措施。生态用水具有时空尺度和阈值范围，而人类大规模的水电开发则会造成其时空尺度的改变，甚至生态阈限难以被满足。统计数字表明，近5年来我国新建水电站下泄生态流量的不满足率达到57％。我国目前急需考虑的生态用水政策是：尽快建立河流最小生态流量的相关标准，制定河流生态用水配套法律法规；同时，通过跨流域调水等水段，加强生态环境需水的宏观调控。建议最小生态用水量不应小于工程所在河流控制断面多年平均流量的10％，当多年平均流量大于80m^3／s时不小于5％；同时根据河流的不同生态环境功能，应积极开展多方法、多方案比选。

Study on theory and methods of river's ecological water in water resources and hydropower

Internal and international studies suggest that, besides water quality, ecological water is another impor- tant factor to sustain a well - balanced ecosystem. So certain ecological water allocation in water resources is an important measure to protect ecological environment. Ecological water has space -time scale and threshold, but its space -time scale will be changed ,even its threshold can not be satisfied because of large -scale hydropow- er construction. Statistics shows that 57% of hydropower stations built in recent 5 years in china cant satisfy the request of ecological water. The policies China must take into account now are ： establishing criterions and correl- ative laws of minimum ecological water in a river, and strengthening macroscopically control of ecological envi- ronment water, for example, south - to - north water diversion. The paper proposes that minimum ecological wa- ter should not be less than 10% of multi- year average discharge at a control section of a river,but not be less than 5% when multi- year average discharge is less than 80 m/s. At the same time,calculation methods of ecological water should be compared according to diversified ecological functions of a river.