西北江三角洲河道水力几何形态对水沙异变的响应研究  

Response of Channel Hydraulic Geometry to Water-sediment Variation in the West and North River Delta

作　　者：杨二静[1,2] 胡涛 YANG Er-jing;HU Tao(Yellow River Conservancy Technical Institute,Kaifeng 475004,China;Henan Engineering Research Center of Eco-hydraulic for Small Watershed,Kaifeng 475004,China)

机构地区：[1]黄河水利职业技术学院,河南开封475004 [2]河南省小流域生态水利工程技术研究中心,河南开封475004

出　　处：《水电能源科学》2021年第9期41-44,49,共5页Water Resources and Power

基　　金：国家自然科学基金项目(51509271);水利部水利技术示范项目(SF201808)。

摘　　要：为探明西北江三角洲河道水力几何关系对上游水沙异变的响应过程,基于珠江三角洲1960~2016年的水沙数据和马口、三水断面实测地形资料,以三水断面为例,采用水力几何关系的计算方法及相对权重法对比分析了河道水力几何关系在水沙异变前后的变化。结果表明,西北江三角洲输沙率受人类活动的影响在1995年后大幅下降,顶点分流分沙比也发生了明显调整,导致三水断面来沙系数的持续减小;河床形态在1960~1984年间基本保持稳定,在1984~2002年间河床剧烈下切,2002年后河床仍保持着持续冲刷的态势,但河床下切幅度有所减小;水沙异变后,西北江三角洲河道断面在自适应过程中逐步形成新的水力几何关系,而洪季来沙系数对断面形态演变的贡献程度明显大于枯季。To investigate the response process of the hydraulic geometric relationship of the channel to the water-sediment variation in the North and West River Delta,based on the water-sediment data in the Pearl River Delta from 1960 to2016 and the measured topographic data of Makou and Sanshui cross-sections,the hydraulic geometric relation method and relative weight method were used to analyze the pre-and post-water-sediment variation at the Sanshui station.The results show that due to human activities,the sediment discharge of the North and West River Delta has decreased significantly after 1995,with significant adjustment of divided water-sediment ratio,which resulted in a continuous decrease of incoming sediment coefficient at Sanshui station.During the 1960-1984,the riverbed changed little.The riverbed occurred significant down-cutting from 1984 to 2002.After 2002,the riverbed continued to be scoured,but the amplitude of downcutting decreased.Due to the water-sediment variation,a new hydraulic geometric relationship of channel is gradually formed in the process of self-adaptation,and the contribution of incoming sediment coefficient to the changes of cross-sectional morphology in flood season is significantly greater than that in dry season.

关 键 词：西北江三角洲 水力几何形态 水沙异变 来沙系数 

分 类 号：TV147[水利工程—水力学及河流动力学]