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Channel evolution under changing hydrological regimes in anabranching reaches downstream of the Three Gorges Dam

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Frontiers of Earth Science 2018年第3期12卷 640-648页

作者： Jianqiao HAN Wei ZHANG Jing YUAN yongyang fan Institute of Soil and Water Conservation Northwest A&F University Yangling 712100 China State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China Bureau of Hydrology Changjiang Water Resources Commission Wuhan 430010 China Changjiang Institute of Survey Planning Design and Research Wuhan 430010 China

Elucidating the influence of dams on fluvial processes can benefit river protection and basin management. Based on hydrological and topographical data, we analyzed channel evolution in anabranching reaches under changing hydrological regimes influenced by the Three Gorges Dam. The main conclusions are as follows： 1） the channels of specific anabranching reaches were defined as flood trend channels or low-flow trend channels according to the distribution of their flow characteristics. The anabranching reaches were classified as T1 or T2. The former is characterized by the correspondence between the flood trend and branch channels, and the latter is characterized by the correspondence between the flood trend and main channels; 2） on the basis of the new classification, the discrepant patterns of channel evolution seen in anabranching reaches were unified into a pattem that showed flood trend channels shrinking and low-flow trend channels expanding; 3） flood abatement and the increased duration of moderate flow discharges are the main factors that affect channel adjustments in anabranching reaches after dam construction; and 4） in the next few decades, the pattern of channel evolution will remain the same as that of the Three Gorges Dam operation. That is, the morphology will fully adapt to a flow with a low coefficient of variation. Our results are of interest in the management of the Yangtze River and other rivers influenced by dams.

关键词： anabranching river channel evolution Three Gorges Dam Yangtze River

Distributed Matching Theory-Based Task Re-Allocating for Heterogeneous Multi-UAV Edge Computing

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China Communications 2024年第1期21卷 260-278页

作者： Yangang Wang Xianglin Wei Hai Wang yongyang Hu Kuang Zhao Jianhua fan College of Communications Engineering Army Engineering University of PLANanjing 210007China The Sixty-Third Research Institute National University of Defense TechnologyNanjing 210007China

Many efforts have been devoted to efficient task scheduling in Multi-Unmanned Aerial Vehicle(UAV)edge ***,the heterogeneity of UAV computation resource,and the task re-allocating between UAVs have not been fully considered ***,most existing works neglect the fact that a task can only be executed on the UAV equipped with its desired service function(SF).In this backdrop,this paper formulates the task scheduling problem as a multi-objective task scheduling problem,which aims at maximizing the task execution success ratio while minimizing the average weighted sum of all tasks’completion time and energy *** three coupled goals in a realtime manner with the dynamic arrival of tasks hinders us from adopting existing methods,like machine learning-based solutions that require a long training time and tremendous pre-knowledge about the task arrival process,or heuristic-based ones that usually incur a long decision-making *** tackle this problem in a distributed manner,we establish a matching theory framework,in which three conflicting goals are treated as the preferences of tasks,SFs and ***,a Distributed Matching Theory-based Re-allocating(DiMaToRe)algorithm is put *** formally proved that a stable matching can be achieved by our *** simulation results show that Di Ma To Re algorithm outperforms benchmark algorithms under diverse parameter settings and has good robustness.

关键词： edge computing heterogeneity matching theory service function unmanned aerial vehicle

Interacting effects of multiple factors on the morphological evolution of the meandering reaches downstream the Three Gorges Dam

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Journal of Geographical Sciences 2017年第10期27卷 1268-1278页

作者： HAN Jianqiao ZHANG Wei fan yongyang YU Mengqing Institute of Soil and Water Conservation Northwest A&F University Yangling 712100 Shaanxi China State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China Changjiang Institute of Survey Planning Design and Research Wuhan 430010 China

Elucidating the influence of dams on fluvial processes can inform river protection and basin management. However, relatively few studies have focused on how multiple factors interact to affect the morphological evolution of meandering reaches. Using hydrological and topographical data, we analyzed the factors that influence and regulate the meandering reaches downstream the Three Gorges Dam （TGD）. Our conclusions are as follows. （1） The meandering reaches can be classified into two types based on their evolution during the pre-dam period： G1 reaches, characterized by convex point bar erosion and concave channel deposition （CECD）, and G2 reaches, characterized by convex point bar deposition and concave channel erosion （CDCE）. Both reach types exhibited CECD features during the post-dam period, （2） Flow processes and sediment transport are the factors that caused serious erosion of the low beaches located in the convex point bars. However, changes in the river regime, river boundaries and jacking of Dongting Lake do not act as primary controls on the morphological evolution of the meandering reaches. （3） Flood discharges ranging from 20,000 to 25,000 m^3/s result in greater erosion of convex point bars. The point bars become scoured if the durations of these flows, which are close to bankfull discharge, exceed 20 days. In addition, the reduction in bedload causes the decreasing of point bar siltation in the water-falling period. （4） During the post-dam period, flood abatement, the increased duration of discharges ranging from 20,000 to 25,000 m^3/s, and a significant reduction in sediment transport are the main factors that caused meandering reaches to show CECD features. Our results are relevant to other meandering reaches, where they can inform estimates of riverbed change, river management strategies and river protection.

关键词： reaches downstream dams meandering river morphological evolution Three Gorges Dam

Suspended sediment load in the turbidity maximum zone at the Yangtze River Estuary： The trends and causes

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Journal of Geographical Sciences 2014年第1期24卷 129-142页

作者： YANG Yunping LI Yitian SUN Zhaohua fan yongyang State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan430072 China

Based on the analysis of suspended sediment elements at estuaries, influence of human activities and estuarine regulation projects on the turbidity maximum zone was studied according to the measurement data between 1959 and 2011. It was found that human activi- ties had little effect on the seaward water while the sharp decrease of sediment volume and concentration in runoff led to the sharp decrease of turbidity maximum zone in the estuary. The concentration at outside sea and Hangzhou Bay did not change, and that along the Subei coast also decreased a little, which had no influence on the turbidity maximum zone. Com- pared with the concentration between 1959 and 1999, the peak of concentration moved up- stream in the estuary, and the concentration in 2000-2009 decreased by about 24.73% with a narrower variation range along the river to the sea. The suspended sediment concentration in North Passage was low in upstream and downstream because of the decrease of seaward sediment and coarsening of bed material, while it was relatively high in the middle due to the influence of sediment cross the north jetty.

关键词： turbidity maximum zone (TMZ) suspended sediment concentration trends and causes Yangtze Riverestuary

三峡水库下游弯曲河型演变规律调整及其驱动机制

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地理学报 2017年第3期72卷 420-431页

作者：樊咏阳张为韩剑桥余梦清武汉大学水资源与水电工程科学国家重点实验室武汉430072 西北农林科技大学杨凌712100

大型水库的兴建深刻改变了下游水沙输移特点,进而导致河床演变规律显著调整,水库下游弯曲河型对水沙过程改变响应敏感,是水库下游河床演变、航道整治、河势控制等方面研究的关键区域。本文基于1996-2016年的实测水文、地形资料,对长江... 详细信息

大型水库的兴建深刻改变了下游水沙输移特点,进而导致河床演变规律显著调整,水库下游弯曲河型对水沙过程改变响应敏感,是水库下游河床演变、航道整治、河势控制等方面研究的关键区域。本文基于1996-2016年的实测水文、地形资料,对长江三峡水库下游弯曲河型的演变规律及其驱动机制开展研究,结果表明:(1)三峡水库蓄水前,下荆江存在"凸淤凹冲"、"凸冲凹淤"两类弯曲河型,而三峡水库蓄水后均表现为"凸冲凹淤"的一致性规律;(2)在水库拦沙作用的影响下,下荆江河段平滩河槽存在累积性冲刷现象,冲刷部位集中于枯水河槽与基本河槽之间的低滩,冲淤部位调整主要由变化的流量过程所驱动,上游河势、河道边界以及支流入汇等因素均有一定驱动作用;(3)在三峡水库蓄水后缺乏大洪水的情况下,凸岸水流挟沙力随流量增加逐渐增强,水流对凸岸冲蚀力度在平滩流量级附近(20000~25000 m3/s)达到最强,平滩流量附近流量级的持续时间超过20天时,弯曲河道发生凸冲凹淤现象。而悬沙中造床粗沙的减少,增强了水流冲刷强度,加剧了凸岸的冲蚀程度。

关键词：水库下游弯曲河型冲淤调整驱动机制下荆江

三峡水库蓄水前后荆江河段冲淤与水沙过程响应

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人民长江 2020年第10期51卷 1-6页

作者：樊咏阳胡春燕陈莫非长江勘测规划设计研究有限责任公司湖北武汉430014

三峡水库蓄水以来,出库沙量(以宜昌水文站实测数据为依据)大幅度降低,坝下游河床冲淤规律也随之发生改变。实测资料表明:荆江河段发生全面冲刷,而沿程冲刷又进一步引起了下游悬沙输移量的变化。基于1992~2017年长江中下游荆江河段各水... 详细信息

三峡水库蓄水以来,出库沙量(以宜昌水文站实测数据为依据)大幅度降低,坝下游河床冲淤规律也随之发生改变。实测资料表明:荆江河段发生全面冲刷,而沿程冲刷又进一步引起了下游悬沙输移量的变化。基于1992~2017年长江中下游荆江河段各水文站实测流量、含沙量数据,对该河段水沙关系进行了较为系统的分析,初步得出三峡水库蓄水前、蓄水初期以及试验性蓄水后不同时期的水沙关系变化。基于实测资料,利用输沙量法计算荆江不同河段的冲淤量随流量的变化,提出了不同时期荆江河段冲刷强度最大的流量级。

关键词：水沙过程河床冲淤河流动力学输沙量法荆江河段三峡水库长江

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长江河口悬沙颗粒特征变化趋势及成因

应用基础与工程科学学报 2016年第6期24卷 1203-1218页

作者：杨云平张明进樊咏阳李义天刘万利工程泥沙交通运输行业重点实验室交通运输部天津水运工程科学研究所天津300456 武汉大学水资源与水电工程科学国家重点实验室武汉430072

以长江口潮区界（大通站）至口外海滨为研究区域,通过对19502013年60余年实测水沙数据的分析,研究了长江河口悬沙颗粒变化特征、趋势及成因.主要结论为:（1）19502013年期间,潮区界d63μm悬沙输运量和百分比均减小,且该组分悬沙主要沉... 详细信息

以长江口潮区界（大通站）至口外海滨为研究区域,通过对19502013年60余年实测水沙数据的分析,研究了长江河口悬沙颗粒变化特征、趋势及成因.主要结论为:（1）19502013年期间,潮区界d63μm悬沙输运量和百分比均减小,且该组分悬沙主要沉积在潮区界至潮流界区间;（2）潮区界至潮流界区间沿程上悬沙粒径伴随d>63μm悬沙输运量减小而减小,20062013年该区间悬沙粒径较19601985年期间为细化趋势;（3）2013年7月潮流界至徐六泾河段的悬沙中值粒径(d50)较2004年8月明显减小,同时20022010年逐年8月徐六泾断面悬沙中值粒径与大通站同步性减小趋势,表明流域悬沙粒径变化已影响至长江口;（4）19981999年、2003年、2007年和20102011年期间南支、拦门沙、口外海滨及北支河段的悬沙中值粒径为减小趋势,百分含量上黏土增加,粉砂和砂略有减小;（5）南港—南槽为粗颗粒悬沙输运通道,2005年8月、2007年8月和2010年8月南港、北港、南槽和北槽悬沙中值粒径均为减小趋势,百分含量上黏土先增加后减小,粉砂先减小后增加,整体上仍以d<63μm泥沙占优势.在成因上,长江流域进入河口d<63μm悬沙输运量的锐减为潮区界至口外海滨区域悬沙细化的主要因素.

关键词：中值粒径分组泥沙趋势及成因地貌学长江河口

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长江口水下三角洲演变规律及河势控制初探

海洋工程 2020年第4期38卷 91-99页

作者：樊咏阳陈正兵张志林胡春燕长江勘测规划设计研究有限责任公司湖北武汉430014 长江水利委员会水文局长江口水文水资源勘测局上海200136

长江河口区水下三角洲的稳定关系着河口区域滩涂湿地的保护、经济社会的发展,研究长江河口区水下三角洲的变化规律,制定相应的控制对策有着重要的意义。基于长江河口区水下三角洲近40年的4个测次的地形资料,采用平面形态与断面形态分析... 详细信息

长江河口区水下三角洲的稳定关系着河口区域滩涂湿地的保护、经济社会的发展,研究长江河口区水下三角洲的变化规律,制定相应的控制对策有着重要的意义。基于长江河口区水下三角洲近40年的4个测次的地形资料,采用平面形态与断面形态分析相结合的方法,探讨了长江河口区水下三角洲的变化规律和相应的控制对策。总体来看,受入海沙量减少的影响,长江河口区水下三角洲前缘10~20 m等深线之间的区域冲刷明显。崇明东滩沙体总体变化不大,横沙东滩、南汇边滩在圈围工程影响下,面积有所淤长。横沙浅滩、九段沙窜沟发育,切割洲滩,沙体稳定性受到威胁,建议对横沙浅滩、九段沙实施守护,以控制长江河口区河势稳定。

关键词：长江口水下三角洲河势变化控制对策

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长江河口口外海滨区域悬沙浓度分布特征研究

水力发电学报 2014年第6期33卷 155-161,167页

作者：黄李冰李义天孙昭华樊咏阳杨云平水资源与水电工程科学国家重点实验室武汉大学武汉430072

根据近期50年长系列长江口水流、含沙量等资料,采用数据分析方法,研究了长江河口口外海滨区域(122°E-123°E)悬沙浓度分布特征及其变化趋势。结果表明:在长江口外海滨区域存在一个,有时甚至两个高悬沙浓度区——由于径流的控制作用,使... 详细信息

根据近期50年长系列长江口水流、含沙量等资料,采用数据分析方法,研究了长江河口口外海滨区域(122°E-123°E)悬沙浓度分布特征及其变化趋势。结果表明:在长江口外海滨区域存在一个,有时甚至两个高悬沙浓度区——由于径流的控制作用,使得无论在洪枯季或大小潮情况下,均在南槽口外形成高悬沙浓度区;其中当径流作用相对较弱时,部分入海泥沙沿东北偏北方向运动,形成第二个高悬沙浓度区。近年来南槽口外的高悬沙浓度区位置有南偏趋势,南、北槽分流分沙比变化是其南偏的主要原因。

关键词：河流泥沙工程学长江河口悬沙浓度分布特征变化趋势