分汊河道平衡水深方法  

A theory of equilibrium depth of branching rivers

作　　者：孙志林[1] 高运[1] 许丹[1] SUN Zhilin;GAO Yun;XU Dan(Ocean College,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]浙江大学海洋学院,浙江杭州310058

出　　处：《哈尔滨工程大学学报》2019年第1期61-66,共6页Journal of Harbin Engineering University

基　　金：国家自然科学基金重大研究计划(91647209);国家重点研发计划项目(2016YFC0402305-02)

摘　　要：为了研究分汊河道的河床演变与航道水深,本文基于水力几何形态关系,得到分汊河道平衡水深计算方法。该方法对于不同断面形态的分汊河道均具有适用性,汊道与单一河道过水断面面积之比为分流比的6/7次方。应用于长江南京以下12. 5 m深水航道二期工程,计算得出的落成洲分汊河段断面的平均水深与多年平均水深基本一致,表明了平衡水深理论的可靠性。对福姜沙和世业洲分汊河段工程前的最大通航水深计算,亦与实际情况较为吻合;工程后的预测结果显示工程整治效果明显,世业洲和福姜沙左汊河段均能满足12. 5 m通航水深的要求,但福北水道仍无法达到12. 5 m通航水深。平衡水深方法提供了一种除数学模型和物理模型外预测河床演变趋势,计算出航道能维持的平衡水深,丰富了航道整治理论的同时,也为二期工程的实施提供科学依据与理论指导。To investigate the evolution of riverbed and waterway depth of a branching river based on hydraulic geometry,this paper proposes a solution to equilibrium depth based on hydraulic geometry.This method is suitable for different cross-sectional shapes of waterway.The ratio of cross-sectional area of a distributary channel to the main stream is a power function of the waterway′s bifurcation ratio with an exponent of 6/7.The theory was applied to the second phase of a 12.5 m deepwater channel of the Yangtze River at Nanjing city.The average depth calculated in Luochengzhou was basically consistent with the average multi-year water depth,which showed the reliability of the equilibrium depth theory.The calculation of the maximum navigable depth of the Fujiangsha and Shiyezhou also agreed well with the actual depth.The forecast results after the second phase project showed that the project remediation effect was obvious,with Shiyezhou and Fujiangsha,in their left branches,able to meet the requirements of 12.5 m navigable depth.However,the Fubei waterway still could not reach this navigable depth.Results showed that the theory of equilibrium depth provides a method for predicting the evolution of a riverbed using mathematical and physical models.It can calculate the sustainable equilibrium depth of a channel,improving waterway regulation,and providing a scientific basis and theoretical guidance for the implementation of the second phase project.

关 键 词：水力几何形态 平衡水深 分汊河道 河床演变 长江 航道整治 最大通航水深 汊道选择 

分 类 号：TV14[水利工程—水力学及河流动力学]