1986—2021年雅江-尼洋河交汇段辫状河道演变过程  

Evolution of braided channels at the confluence of Yarlung Tsangpo and Niyang River from 1986-2021

作　　者：游宇驰 李志威 余国安[3] 胡旭跃[1] YOU Yuchi;LI Zhiwei;YU Guo′an;HU Xuyue(School of Hydraulic and Environmental Engineering,Changsha University of Science&Technology,Changsha 410114,China;State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,China;Key Laboratory of Water Cycle and Related Land Surface Processes,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China)

机构地区：[1]长沙理工大学水利与环境工程学院,湖南长沙410114 [2]武汉大学水资源工程与调度全国重点实验室,湖北武汉430072 [3]中国科学院地理科学与资源研究所中国科学院陆地水循环与地表过程重点实验室,北京100101

出　　处：《水科学进展》2023年第2期265-276,共12页Advances in Water Science

基　　金：国家自然科学基金资助项目(41971010,51979012)。

摘　　要：雅鲁藏布江与尼洋河交汇段的辫状河道形态及变化主要受尼洋河入汇、河谷边界条件及滨河植被的影响,时空变化的差异性和复杂性值得研究。利用1986—2021年遥感数据提取河道-沙洲-植被主要形态参数(主河道迁移率、弯曲率、面积等)分析辫状河道形态的复杂特征与演变过程。结果表明:主河道迁移率最大为483 m/a,曲率减小3.43%,植被面积逐年增加到8.05 km^(2)。米林—派镇段辫状河道受边界条件和水文条件的差异影响,主河道在尼洋河汇入前呈横向单侧摆动,汇入后雅鲁藏布江主河道同时发生横向与纵向摆动;2013年以来该河段的植被仅有11.8%的覆盖区域对河床产生抑冲促淤的正向反馈并促进沙洲的稳定。The morphology and variation of braided channel at the confluence reach of Yarlung Tsangpo River(YTR)and Niyang River are affected by the inflow of Niyang River,valley boundary and vegetation conditions.The spatiotemporal variation and complexity of of the braided river are of importance to further study.The remote sensing images from 1986 to 2021 were used to extract the morphological features of braided channels,sandbar and vegetation(channel migration rate,sinuosity,area,et al).We further analyze the morphological characteristics and evolution processes of complex braided channels.The results show that maximum migration rate of the main channel is 483 m/a,the sinuosity reduces by 3.43%,and the vegetation cover area increases up to 8.05 km^(2).Owing to the difference of boundary conditions and hydrological conditions,the main channel of the Milin-Paizhen reach oscillates laterally before the Niyang River flows into the YRT,and migrates laterally and longitudinally after Niyang River flows into the channel.Since 2013,11.8%of the vegetation coverage in the river channel has a positive feedback of erosion inhibition and deposition promotion,and enhanced the stability of the sandbars.

关 键 词：辫状河道 河道交汇 水沙条件 边界条件 植被作用 

分 类 号：TV147[水利工程—水力学及河流动力学]