小水电影响下的南方山区河流适宜生态流量

Suitable River Ecological Flow in Southern Mountainous Areas Under Influence of Small Hydropower

小水电不合理开发、忽视河流生态流量需求等问题给下游河段水文生态带来不利影响,破坏了水生生物的栖息地环境。以广西壮族自治区大环江下湘电站下游河段为例,选择鲤鱼作为目标鱼类,基于鲤鱼流速和水深适宜性曲线,采用生境模拟法模拟分析11个流量工况下研究河段水动力分布特征和鲤鱼质量生境面积分布特征,并运用水文学方法,基于三个评价指标评价最小生态流量的适宜性。结果表明,利用生境模拟法计算的枯水期鲤鱼生存的适宜生态流量为9.38 m^(3)/s、最小生态流量为6.25 m^(3)/s,结果合理、适宜,对于保障小水电下游河流生态环境健康具有重要意义。

The problems,such as unreasonable development of small hydropower and the neglect of the river ecological flow demand,can negatively impact the hydrological ecology of the lower reaches and damage the habitat environment of aquatic organisms.Taking the Xiaxiang hydropower station in the Dahuan River Basin of Guangxi Zhuang Autonomous Region as the research reach,carp was selected as the target fish.Based on the suitability curve of carp velocity and water depth,using the habitat simulation,the characteristics of hydrodynamic distribution and carp mass habitat area distribution under 11 flow conditions were analyzed.The results show that the suitable ecological flow of target fish in dry season is 9.38 m^(3)/s,and the minimum ecological flow is 6.25 m^(3)/s.The comparative analysis was carried out by using the hydrology method,and the suitability of the minimum ecological flow was evaluated by three evaluation indexes.The results show that the suitable ecological flow and the minimum ecological flow of the habitat simulation are reasonable and suitable.The research results are of great significance to ensure the ecological environment health of the downstream rivers of small hydropower stations.