日调节水电站峰荷流量持续时间对鱼类栖息地的影响

The Influence of Peak Load Flow Duration of Daily Regulating Hydropower Station on Fish Habitat

日调节水电站调峰运行将产生河道非恒定流,造成河流下游水生生物栖息地质量和水生生态系统的生产力明显下降,水生生物尤其是鱼类的生存和繁衍受到严重影响。电站非恒定流在传播过程中具有衰减及坦化的特性,峰值流量沿程减小,其减小程度与峰荷流量持续时间有关。因此电站调峰运行峰荷流量的持续时间是影响鱼类栖息地的重要因素。提出了静水区和动水区的概念,并利用一维非恒定流数学模型,以西南山区某水电站为例,按照不同的峰荷流量持续时间设置4种调度方案,研究探讨了日调节水电站调峰运行峰荷流量的持续时间对下游鱼类栖息地的影响程度。分析表明,不同的峰荷流量持续时间对鱼类栖息地的影响程度不同,产卵场受非恒定流影响较大,在鱼类产卵时期下泄峰荷流量持续时间应尽量缩短。

The peaking operation of daily regulating hydropower station will produce unsteady flow and cause aquatic habitat quality and ecosystem productivity of lower river decreased significantly.The survival and reproduction of fish is greatly destroyed.Unsteady flow of hydropower stations will attenuate with time during the propagation,because of this characteristic,peakflow will decrease along the procedure,and the decrease degree depends on the duration of peak flow.Therefore,the duration of peak flow is an important factor that affects the fish habitat.This paper proposes the concepts of hydrostatic zone and hydrodynamic zone,and uses one-dimensional unsteady flow mathematical model,taken a hydropower station in southwest mountainous area for example and set four scheduling schemes to discuss the influence of peak flow duration.The results show that different peak flow duration affects fish habitat in different degrees,and the spawning grounds affected by unsteady flow of a larger,peak flow duration should be as short as possible during spawning period of fish.