沱沱河辫状河道多尺度形态特征及非活跃汊道的影响  

Multi-scale morphological characteristics of braided channels and impacts of inactive branches in the Tuotuo River

作　　者：何育聪 李志威 夏军强[1] 周银军[2] HE Yu-cong;LI Zhi-wei;XIA Jun-qiang;ZHOU Yin-jun(State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,China;Changjiang River Scientific Research Institute,Wuhan 430010,China)

机构地区：[1]武汉大学水资源工程与调度全国重点实验室,湖北武汉430072 [2]长江科学院,湖北武汉430010

出　　处：《泥沙研究》2024年第1期38-44,共7页Journal of Sediment Research

基　　金：国家自然科学基金项目(52239007);国家重点研发计划项目(2022YFC3201703-05);湖北省技术创新重点研发计划项目(2023BCB110)。

摘　　要：目前对长江源辫状河流的形态特征已有初步认识,但缺乏河段多尺度形态特征与非活跃汊道的影响研究。基于GEE和PyRIS,使用Landsat 8、Sentinel-2遥感影像、STRM V4地形数据和沱沱河站2013-2018年逐日流量数据,分析沱沱河多尺度的辫状平面形态特征及非活跃汊道的影响。结果表明:全河段平面形态呈宽窄相间的藕节状,且汊道随流量增大呈先增多后增宽的阶段性变化特征。子河段辫状强度与活动水域面积比呈先增后减的抛物线型变化规律,与水面展宽呈正幂律关系。非活跃汊道仍具有辫状河道的辫状强度特征,其地形较高,缺少漫滩机会,内部非活跃汊道形态稳定,年内摆幅小于10 m。At present, the morphological characteristics of braided rivers at the Source Region of the Yangtze River have been preliminarily studied, but there is still a lack of research on the morphological characteristics of multi-scale braided reaches and impacts of inactive branches. Based on Google Earth Engine, PyRIS and Landsat 8, Sentinel-2 remote sensing images, STRM V4 data and daily average flow discharge at the Tuotuo River Station from 2013 to 2018, the braided plane morphological characteristics in multi-reach scales and the impacts of non-active branches are analyzed. The results show that the studied entire channel is in the shape of lotus-root with alternative wide and narrow reaches, and the braiding intensity has a stage characteristic of increasing the branch number first and then widening the branch with the increase of flow discharge. The ratio of braided intensity to active water area in the sub-reaches shows a parabolic pattern of first increasing and then decreasing, and a positive power law relationship with water surface widening as flow discharge increases. The inactive channels still have the braiding intensity characteristics of braided channels. However, due to the higher terrain of floodplain and limited opportunities for flooding, the inactive channels are more stable and the annual lateral migration of their internal branches is less than 10 m.

关 键 词：辫状河道 形态特征 非活跃河道 日均流量 遥感影像 长江源 

分 类 号：TV147[水利工程—水力学及河流动力学]