水库排沙对下游河流鱼类影响研究进展

水库排沙对减轻水库淤积、延长水库寿命和恢复河流泥沙连续性等方面有着重要意义,但是水库进行水力排沙时水库下游河流水体的物理和化学性质的变化可能对鱼类等水生生物产生不利影响,严重时出现死鱼现象.国内外水库排沙时期下游河道含沙量及其颗粒级配、溶解氧浓度、污染物等水质变化对鱼类影响研究表明,微颗粒泥沙淤堵鱼鳃影响其摄入氧气功能和水体溶解氧下降是影响鱼类的两个主要因素,且含沙量及其持续时间、颗粒级配等对鱼类影响机理不同.最后展望了我国今后水库排沙对下游河流鱼类研究内容.

Research progress of impacts of sediment flushing on downstream fish

Sediment flushing has great significance to reduce reservoir sedimentation,extend the life of reservoirs and restore the continuity of river sediment transport,etc.However,the changes in physical and chemical properties of downstream river water may adversely affect aquatic life;seriously,fish will die.The effects downstream suspended sediment,particle size distribution,dissolved oxygen concentration,pollutant and other water quality changes on fish are studied during sediment flushing at home and abroad.The research shows that the two main factors affecting the fish life are the reduction of oxygen intake function by micro sediment particles clogging the gills and the declination of dissolved oxygen concentration in water.Suspended sediment and its duration,particle size distribution,etc.have different mechanisms for fish.Finally,the studies of the impact of sediment flushing on downstream fish are prospected in China.