黄河口双流路同时行河运用年限研究

Study on Service Life of Flow Paths with Using Parallel⁃Running Mode in Two Flow Paths of Yellow River Estuary

刁口河已停河46 a,流路湿地生态系统萎缩、退化严重,刁口河、清水沟流路同时行河可以为刁口河提供水沙补给,扩大自然湿地面积、恢复岸线自然延伸趋势。针对河口河段不淤临界流量开展研究,并设置不同分流比方案,利用河口多流路行河水沙演进数学模型,计算分析了以清水沟流路为主、刁口河流路为辅的行河年限。结果显示:河口河段冲淤临界流量为1600~2200 m^(3)/s;当大河(利津断面)来流大于3800 m^(3)/s时,在清水沟流路达到平滩流量4000 m^(3)/s前按照1600 m^(3)/s向刁口河分流,之后逐渐增加分流流量到4000 m^(3)/s,对清水沟流路行河年限、水位影响较小;若进一步减小大河起分流量,增加刁口河分水分沙量,会对清水沟流路行河年限造成较大影响。流路行河年限受水沙条件、地形边界、海洋动力等多因素影响,设计水沙条件下双流路同时行河,可在尽量发挥清水沟流路运用潜力的基础上,最大限度为刁口河补水补沙,利于湿地生态系统的保护和修复。

The Diaokou River channel has stopped its operation for 46 years,and the wetland ecosystem of the flow path shrinks and degener⁃ates seriously.However,if the Diaokou and Qingshuigou flow paths are used simultaneously,it can provide water and sediment supply for the Diaokou River,expand the area of natural wetlands and restore the natural extension trend of the coastline.Based on the study of non⁃silting critical flow in the estuary,different diversion ratio schemes were set,and the mathematical model of river sediment evolution in the estuary with multiple flow paths was used to calculate and analyze the simultaneous operation years of the two flow paths that Qingshuigou flow path is the main and Diaokou River path is the auxiliary.The results show that the critical flow rate for flushing and siltation in the estuary section is 1600-2200 m^(3)/s.When the incoming flow of the Yellow River(Lijin section)is greater than 3800 m^(3)/s,before the bankfull discharge of Qingshuigou flow path reaching to 4000 m^(3)/s,according to the plan of diverting 1600 m^(3)/s to Diaokou River,and then gradually increasing the discharge of diversion to 4000 m^(3)/s,the impact on the service life and water level of Qingshuigou flow path is smaller.If further reduce the diversion discharge from the Yellow River and increase the amount of water and sediment diversion of Diaokou River,it will cause a more serious impact on the service life of Qingshuigou flow path.If the service life of the flow path is affected by many factors,such as water and sediment conditions,topographic boundaries and ocean dynamics and simultaneous flow of rivers on dual flow paths under designed water and sediment conditions,the Diaokou River can be replenished with water and sediment to the greatest extent on the basis of giving full play to the application potential of Qingshuigou flow path,which is conducive to the protection and restoration of the wetland ecosystem.