【摘要】 河流生态水文情势对生态系统起着决定性作用,定量评估日调节电站库区中部生态水文情势影响,可为日调节电站的生态调度,维持河流生态健康等提供科技支撑。采用变动范围法(RVA)对湘江干流大源渡枢纽库区衡阳水文站1959～2015年逐日流量、水位及流速指标进行分析,采用生物多样性指标SI初步评估库区生物多样性的变化。结果表明:日调节电站蓄水后,库区中部生态水文变化特征及生态影响为:流速IHA指标整体改变度达到81%,流量IHA指标整体改变度为43%;4～7月月均流速降低(高度改变)不利于"四大家鱼"产卵活动;库区年极小值流量的增加利于保障自然栖息地和植物群落;年极值流速降低在改变库区河道地貌的同时加大生态环境风险;流量、流速年最小值出现时间发生100%改变,影响生物的生命活动;流量低脉冲历时和流速高脉冲历时高度改变,不利于刺激家鱼产卵繁殖活动;枢纽蓄水后SI值降低,生物多样性降低。更多还原

【Abstract】 The river ecological hydrological situation plays a decisive role in the ecosystem, to evaluate quantitatively the influence of ecological and hydrological situation of daily Regulating power station reservoir area, it can provide scientific and technological support for the ecological operation of power stations and the maintenance of the ecological health of rivers. In this paper, variation range method(RVA) was used to analyze the daily flow rate, water level and flow velocity indicators of Hengyang hydrological station in Dayuandu junction reservoir area of Xiangjiang river main stream from 1959 to 2015, and the change of biodiversity in the reservoir area was preliminarily evaluated by the biodiversity index SI. The results show that after daily regulation of water storage in the power station, the characteristics and ecological influence of the ecological and hydrological changes in the reservoir area are as follows: The overall change degree of flow rate IHA index reached 81%, and the overall change degree of flow velocity IHA index reached 43%; In 4-7 month, the monthly average flow velocity decreased(height changed), which was not conducive to the spawning activities of "The four major Chinese carps"; The increase of annual minimum flow in the reservoir area is beneficial to the protection of natural habitats and plant communities; The decrease of annual extreme flow velocity increases the risk of ecological environment while changing the river landform in the reservoir area; The minimum annual value of flow rate and flow velocity changes by 100%, affecting the life activities of organisms; The changes of low flow rate pulse duration and high flow velocity pulse duration are not conducive to stimulate spawning and reproduction of domestic fish, After impoundment, SI value and biodiversity decreased.更多还原