摘要
清水沟改道及龙羊峡、小浪底水库运用后,黄河口尾闾河道的河床形态发生了显著调整。黄河口尾闾河道河床调整过程总体分为四个阶段,分别为:1976—1980年淤滩成槽阶段,1980—1984年单股入海阶段,1984-1999年主槽萎缩阶段,1999—2016年河床冲刷阶段。研究发现:清水沟改道初期,河床平面形态宽浅散乱,河口迅速延伸,河长从75.1 km增加到93.2 km。1980年后,河道逐渐形成单一顺直的河型,入海口逐渐南偏,河口延伸速率减小。1984—1999年,主槽萎缩严重,平滩面积减小了61%;深泓摆动剧烈,其摆动距离及强度分别为102 m及0.17。小浪底水库运用后,河床剧烈冲刷,平滩水深增加了41%;深泓摆动幅度减小,其摆动距离及强度分别减小至37 m及0.09。此外还建立了1999年后平滩形态参数及深泓摆动强度与前4年汛期平均水流冲刷强度的经验关系,一定条件下可用于反演河床形态随水沙条件的调整过程。
Remarkable channel adjustments have occurred in the Yellow River estuary since the 1996 artificial avulsion from the Diaokouhe course to Qingshuigou course. The channel has evolved through four stages: rapid aggradation, undercutting, shrinkage, and severe degradation. Its geometrical variations indicate that(i) in the initial stage of 1976-1980, the study reach was drastically aggraded, with its length increasing from 75.1 km to 93.2 km;(ii) during 1980-1984, numerous branches near the river mouth were gradually coalescing into a single channel toward the southeast, and channel undercutting was dominant;(iii) after 1984, the channel’s bankfull area was decreased by 61% in severe shrinkage caused by the operation of Longyangxia reservoir, with its thalweg migrating frequently at a migrating intensity and width of 0.17 and 102 m respectively;(iv) during 1999-2016, its bankfull depth was increased by 41% and the migrating intensity and width decreased to 0.09 and 37 m respectively. In addition, we develop empirical relationships of reach-scale bankfull dimensions and thalweg-migrating intensity versus the average flow scour intensity over previous four years, which give satisfactory predictions of channel adjustments highly correlated with the real case.
作者
张诗媛
夏军强
万占伟
李洁
ZHANG Shiyuan;XIA Junqiang;WAN Zhanwei;LI Jie(State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wulaan 430072;Yellow River Engineering Consulting Co.,Ltd.,Zhengzhou 450003)
出处
《水力发电学报》
EI
CSCD
北大核心
2019年第1期63-74,共12页
Journal of Hydroelectric Engineering
基金
国家重点研发计划课题(2017YFC0405501)
国家自然科学基金(51725902
51579186)
关键词
清水沟河道
河床调整
平面形态
断面形态
黄河口
Qingshuigou channel
channel adjustments
bankfull channel geometry
planform geometry
Yellow River estuary