黄河下游游荡型河段床面形态变化特征  

Variation Characteristics of Bedforms in Wandering Reach of the Lower Yellow River

作　　者：张原锋[1] 王平[1] ZHANG Yuanfeng;WANG Ping(Yellow River Institute of Hydraulic Research,YRCC,Zhengzhou 450003,China)

机构地区：[1]黄河水利委员会黄河水利科学研究院,河南郑州450003

出　　处：《人民黄河》2018年第8期8-11,共4页Yellow River

基　　金：国家自然科学基金资助项目(51379087);中央级公益性科研院所基本科研业务费专项(HKY-JBYW-2017-07)

摘　　要：床面形态是水流阻力及泥沙输移的重要组成部分。利用床面形态控制数及床面形态判别方法,结合黄河下游花园口河段多波束水下三维地形及河床纵剖面资料,研究发现黄河下游游荡型河段床面形态主要表现为沙垄、过渡及动平整。当流量逐渐增大时,床面形态逐渐由沙垄向过渡、动平整方向发展。天然条件下,当流量小于1 500 m^3/s时,床面主要表现为沙垄,床面形态的波长与波高之比平均为550;当流量大于2 000 m^3/s时,床面形态主要为动平整。在持续冲刷条件下,当流量小于1 500 m^3/s时,床面形态表现为双尺度沙垄,即波高为0.2~1.2 m的小尺度沙垄叠加在波高为2~3 m的大尺度沙垄的迎水面与背水面上。Bedform is very important part to resistance to flow and sediment transport. Based on the bed longitudinal profiles and bedform maps obtained by Multi-Beam Echo Sounding（ MBES）,we found out dunes,transition and upper plane bed types dominate wandering reach of the lower Yellow River with the control factor and bedform discriminator. As the water discharge increases,bedform develops from dunes to transition and upper plane beds. Under natural condition,at low flow with discharge less than 1 500 m^3/s,dunes are dominant and the ratio of bedform length to height is larger,550 on average. When the high flow discharge is greater than 2 000 m^3/s,upper plane beds are dominant. Under the condition of sustainable scouring,two scales of dunes are found when low flow with discharge less than 1 500 m^3/s,i.e. the small scale dunes with bedform height 0. 2-1. 2 m superposed on the both river side and land side of the larger scale dunes with bedform height 2-3 m.

关 键 词：动平整 双尺度沙垄 床面形态 游荡型河段 黄河下游 

分 类 号：TV147[水利工程—水力学及河流动力学] TV882.1