黄河河口鱼类春季生态需水

黄河河口鱼类春季生态需水主要满足河道淡水鱼类栖息地及产卵场、河道洄游鱼类上溯通道和近海洄游鱼类低盐产卵场需求。综合考虑鱼类生活习性,径流传播以及与近海淡咸水混合时间和小浪底水库运行以来月均流量特征,鱼类需水应重点关注3—5月。依据河道淡水鱼类和洄游鱼类的生活习性,从洄游通道的全程连续性出发,需要的低流量为240 m~3/s。结合自然时期流量脉冲特征,每年需要一次4月中旬持续8 d的峰值为890 m~3/s的流量脉冲;在此条件下,春季入海径流量为21.6亿m~3,已满足近海洄游鱼类低盐产卵环境要求的21亿m~3冲淡水量。小浪底水库运行以来,平均春季径流量已达到21亿m~3。通过优化年内或年际调度模式,满足鱼类春季生态需水具有很大可行性。

Spring ecological water requirement for fishes in Yellow River Estuary

Spring ecological water requirement for the fishes in the Yellow River Estuary should meet the needs of the habitat and spawning ground of freshwater fishes, channel of migratory fishes, and spawning ground of offshore migratory fishes. According to the living habit of fishes, the time of runoff propagation, the mixing time of fresh water and salt water, and the discharge feature since the operation of the Xiaolangdi Reservoir, key attention should be paid to the water requirement from March to May. A minimum ecological flow discharge of 240 m³/s is needed according to the living habit of fishes and the continuity of the migration channel. A flow discharge pulse with a peak of 890 m³/s, lasting for 8d in the middle stage of April is also needed considering the pulse characteristics in nature period. In this condition, the runoff in spring is 21. 6×10⁸ m³, satisfying the requirement of 21×10⁸ m³ for the low salt spawning condition of offshore migratory fishes. The mean annual spring runoff is 21×10⁸ m³ since the operation of the Xiaolangdi Reservoir. It is of great feasibility to satisfy the fish ecological water requirement by optimizing the annual or the interannual operation modes.