面向河流生态完整性的黄河下游生态需水过程研究

提供适宜的生态流量对维护河流健康和支撑人类社会发展具有重要意义。尽管栖息地模拟法物理机制清晰、应用广泛,但对生物群落考虑不足、生命节律信号缺失等问题长期存在。以维护河流土著生物群落完整性为目标,本文将天然水文情势作为参照系统,结合栖息地模拟与水文参照系统特征值,建立了一种面向河流生态完整性的生态需水过程评估方法,兼顾指示物种生存繁衍和土著生物群落基本生存。黄河下游利津断面评估结果显示:利津断面年最小生态需水量119亿m~3,适宜生态需水量130～137亿m~3,涨水期需提供1～2次持续时间不低于7 d、流量不低于1220 m~3/s的高流量脉冲。对比历史实测流量过程与本文生态需水成果,发现利津断面水量充足,但流量过程不满足生态需求。黄河需加强水库群调度,协调径流年际和年内分布,塑造适宜的生态流量过程,并适时塑造高流量脉冲。

Research on the ecological integrity-oriented environmental flow regime of the Lower Yellow River

Providing appropriate environmental flow regime is important to maintain river health and support the development of human society. Despite the clear physical mechanism and wide application of the habitat simulation method,the accuracy of which is often questioned due to insufficient indicator species and ignorance of life rhythm signals. In order to maintain the native ecological integrity of the riverine ecosystem, the natural flow regime is taken as the hydrological reference system to develop an ecological integrity-oriented environmental flow regime assessment method by coupling habitat simulation with characteristic values of hydrological reference system. This method can ensure the survival and reproduction and indicator species and the survival of native biocommunity. The assessment results of Lijin in the Lowe Yellow River show that the minimum annual environmental flow requirement in Lijin is 11.9×10⁹ m³;the suitable environmental flow requirement in Lijin is 13.0×10⁹ m³~13.7×10⁹ m³; 1~2 high flow pules which last more than 7d and more than 1220 m³/s need to be provided in the rising water season. By comparing the historical measured flow data and the environmental flow demand results in this paper,the total water volume is sufficient but the flow process could not satisfy the environmental flow regime requirement in Lijin. Therefore, it is necessary to enhance the reservoir group intra-annual and inter-annual regulation to provide appropriate environmental flow regime and create high flow pulses in suitable time.