洞庭湖响水坎跌水碍航险滩整治方法研究

响水坎跌水严重碍航,是洞庭湖区急待整治的重点滩险,类似滩险在国内外湖区中均极其少见。本文采用遥感地质分析方法与水动力演变分析方法分析洞庭湖草尾河响水坎滩险成因。分析结果表明:地层岩性与沉积厚度的突变、构造单元分布等地质因素是导致响水坎原始河床跌坎形成的内在原因;原始跌坎存在是出现跌水的前提,河湖边界及来水来沙变化是跌水存在的外在条件,水文组合决定了滩险是否碍航。在对跌水滩险形成原因正确认识的基础上,提出了采用超长距离变底坡加局部拓宽疏浚挖槽的航道整治方案,整治工程实施后的实测资料分析表明,整治是成功的。     

钱塘江河口沙坎演变的数值模拟研究

运用Delft3D软件模拟钱塘江河口沙坎的形成演变过程,探讨钱塘江河口沙坎的演变机理.将钱塘江河口概化为喇叭形,假定底质泥沙粒径单一,不考虑波浪作用,在径流和潮汐的作用下,建立钱塘江河口沙坎演变的数值模拟,重现沙坎演变的过程.钱塘江河口沙坎的形成演变主要受水动力、泥沙输运、河床演变三者非线性相互作用的控制.流域来水与外海潮汐的相互作用为沙坎提供了水动力条件,外海巨量泥沙输入为沙坎形成提供了丰富的泥沙来源.     

湄公河-洞里萨湖河湖关系与水文情势驱动响应研究——关键科学问题与技术实现路径

湄公河与洞里萨湖河湖关系是世界上著名江湖关系的典型代表，同时受上游来流、下游潮汐、区域风浪、洪泛区调蓄等影响，水情叠加互馈效应(遭遇、倒灌、补水、漫滩、顶托、调蓄)巨大，水文过程集成度高。从河湖水文情势变化规律、河湖耦合水文水动力学模型、河湖水量交换关系及水情驱动机制3个方面阐述了湄公河-洞里萨湖河湖关系与水文情势驱动响应机理研究进展，并研究了其关键科学问题与技术实现路径。结果表明：(1)湄公河与洞里萨湖水文-水动力作用机理复杂且尚不明晰，成为制约湄公河和洞里萨湖综合治理的瓶颈问题；(2)未来亟需加强研究的重点方向主要包括构建湄公河与洞里萨湖大型连通水网水文-水动力耦合模型，精细模拟河湖水情组合叠加效应的时空量演变特征，定量揭示洞里萨湖河湖互相转换特性，理清河湖交互规律的宏微观格局，定量评估径流、潮汐、风浪遭遇组合对河湖水量交换的影响量，阐明河湖水情-水动力条件-水通量交互-湖区水文节律的驱动机制和耦合协变响应规律，以及创建河湖水量交换关系内涵变化量与洞里萨湖全区域全过程水文情势变化量的定量关系知识图谱。研究成果对丰富江湖关系内涵、指导柬埔寨洪旱灾害应对、提高水文预报精度、确保河湖健康具有极其重要的科学理论意义和实践应用价值。     

河口村水库坝下泄洪区出口整治及生态修复

河口村水库泄水建筑物泄洪洞和溢洪道采用挑流消能,挑射的水流具有强大的冲刷作用,在建筑物下游出口河床产生了较大范围的冲刷坑,为了保护泄洪出口区域安全与坝下游河道生态环境,确保下游建筑物安全,对泄洪建筑物出口河道进行整治与生态修复。通过水力计算及模型试验得出了泄洪出口挑流冲刷的影响范围,通过设置河心滩进行导流分流,降低河道流速,并增设不同位置的跌水坎形成消力塘和水垫;河心滩、防冲墙、跌水坎紧邻泄洪出口区布置,保护了相邻建筑物的安全;结合下游河道自然形态和周边环境,创造高滩、沙洲、岛屿等多种类型物理生境。     

渭河咸阳陇海铁路桥下游段河床跌坎式下切的成因及危害性分析

自2013年以来,渭河咸阳陇海铁路桥下游出现了河床跌坎式下切险情,改变了河床原状,对该河段的沿河建筑物安全运行造成了威胁。为了防止下切继续发展,就必须分析河床下切形成的原因,才能有针对性的制定应对措施。本文结合渭河水文、泥沙、河床地质等资料,对河床变化及河水水沙变化等方面进行分析,得出河床下切的主要成因及危害性,并预测下切发展趋势,为下一步采取治理措施提供参考。     

黎河河道演变的数学模型——天然河道用作输水通道后的演变

天然条件下的山前性河流黎河被用作引滦入津的输水河道，来水条件的巨变和大量工程引起的河床调整，为研究这一调整我们建立了具有如下特点的数学模型：1、考虑了自上而下床沙粒径的巨大变化；2、反映了卵石夹沙河床宽级配的输沙特点以及清水冲刷时的粗化过程；3、模拟了粘性土河床的冲刷特性；4、考虑了跌水坎的不规则断面宽顶堰的过流特点以及有工程措施和人为干扰下的河床演变特点。本文介绍了上述数学模型的主要内容，这对于其它跨流域引水工程和河道治理工程有参考价值。     

三峡水库175m蓄水后荆江典型分汊河段演变趋势预测

三峡水库蓄水后,长江中游局部河段冲刷调整剧烈,尤以分汊河段最为显著,给航运及河势稳定带来了一系列不利影响。以荆江典型分汊河段——沙市河段为例,分析了三峡水库蓄水前后的演变特点,明确了水动力条件、来沙变化及洲滩相互作用对河床演变的重要影响,并提出了影响滩槽变化的特征流量级的概念。在此基础上,采用数学模型对河床演变的趋势进行预测,结果表明,该河段的滩槽格局将进一步调整,通航安全问题仍然存在。     

再论闽江下游河床演变及其水力条件的变化

该文根据历年实测大量水文、水位、流量、泥沙等资料,应用水文水力学原理分析闽江下游河床演变及其水力条件变化。研究结果表明,在河流水动力作用下,闽江下游河床下切严重。据此提出采砂规划工作和恢复河口测验工作的建议。     

长江监利河段近期河道演变分析

监利河段地处荆江尾部,受洞庭湖来水顶托和江湖关系变化影响均较大,水文泥沙条件变化和河床演变较为剧烈,对防洪航运、堤防护岸、港口码头、农田建设等都带来深刻影响,是长江流域规划重点整治河段之一.依据河段来水来沙及边界条件,分析了监利河段主泓线、深泓纵剖面、岸线、洲滩及汊道、冲淤等变化规律,总结了该河段的演变特征,预测了监利河段的演变趋势.     

珠江东平水道航道整治试验研究

东平水道整治河段位于珠江西，北两江交汇区，不同类型浅多，水流条件复杂，而行洪干道之一，整治难度很大。在掌握大量原型水文和河道地形资料基础上，进行水动力条件，来水来沙条件和河床演变分析，结合模型试验研究，揭示浅滩成因和形成机理，采取有针对性的整治工程，使东平水道航道整治取得良好的效果。     

Navigational safety at risk: The impact of sand Mining in a key waterway in China

The Caowei River is an important part of the planned high-grade waterway network in China. Since 2016, the deterioration in the navigation flow conditions of the Xiangshuikan reach has made traveling upstream through the waterway more difficult for ships and raised emerging navigation safety concerns. To better understand the causes of the deterioration in the waterway navigation conditions after 2016, we examined the topographic and hydrological changes of the Caowei River and investigated the navigable flow conditions of the Xiangshuikan reach. The results showed that the Caowei River has generally been scoured since 2006 due to sediment depletion and that the dramatic riverbed downcutting (15.47 m in the deepest cut of thalweg elevation) in the Xiangshuikan reach was likely caused by illegal sand mining which extracted the fine sand underlying the clay overburden in this segment and led to the formation of two extremely large steep headcuts. It was found that a large water surface gradient, rapid flow velocity, and disordered flow pattern occurred near the larger upstream headcut during the low-water-level period, which made ship navigation more challenging. In 2019, the measured maximum local water surface gradient and maximum flow velocity reached 3.97‰ and 3.28 m/s, respectively. Additionally, the increase in the low flow at Caowei station and the decrease in the low water level at Lujiao station further aggravated the navigation conditions of the Xiangshuikan reach. These findings reveal the considerable complexity of the response of the channel navigation flow conditions to the topographic and hydrological changes in the lake area, providing valuable information for channel regulation and river management in the Dongting Lake area and other rivers.     

船舶上滩的影响因素及动水特性试验

在急流滩地形概化了的试验水槽中，进行了多种水力条件下的船模上滩试验．试验结果表明，滩段的水面比降、水流速度及船舶水深吃水比是船舶上滩的主要影响因素．     

石质急流滩水力特性概化试验研究

根据溪口型急流滩概化滩段的水槽试验，分析了急流滩段流速与水位的分布和沿程变化等水力特性，阐述了滩段水力特性与地形的关系，以及影响滩情的主要因素，讨论了计算滩段水面线中确定局部阻力系数的方法，     

山区河流航道整治方法综述

山区河流坡陡流急,各种碍航滩险随处可见。分析了山区河流石质滩险的各种碍航流态及水利特性以及对船舶航行的影响,并提出各碍航滩险的整治措施。     

含植物河道等效床面阻力试验研究

植物广泛存在于滩地和河槽中,可有效改善水环境,但同时也增加了水流阻力。通常采用不同材料的棍状物或仿生植物模拟实际植物进行试验研究,将植物阻力附加于床面上与原床面阻力一起构成等效床面阻力,因模拟实际植物的不相似导致含植物河道等效床面阻力的研究不够完善。本文提出了对实际植物分区施加实际流速条件进行试验的思路,即按河道现场调研的植物密度布置,沿横向和垂向对河道横断面分区,对实际植物区域施加实际流速条件,试验研究分区水体中的植物阻力,最后换算得到表征等效床面阻力的等效床面糙率。以独流减河上游河道为对象,选用乔木、灌木和芦苇三种典型植物,考虑河道横断面不同分区的流速条件进行了试验,结果表明,当遭遇100年一遇洪水时,乔木种植区域的等效床面糙率为0.060～0.066,灌木种植区域的等效床面糙率为0.083～0.099,芦苇种植区域的等效床面糙率为0.698～0.989。研究成果可为防洪计算和水环境治理提供理论支持。     

三峡水库蓄水后观音滩汛期航道条件变化分析

为了进一步提高三峡工程的航运效益,通过平面二维数学模型和实测资料分析了三峡水库运行后,库区观音滩洪水急流滩的汛期航道条件变化情况及船舶自航上滩的临界条件。结果表明,三峡成库后,观音滩河段汛期航道条件大幅改善,航道水深增加,断面垂线平均流速减小,且分布趋于均匀化,河宽增大。万吨级船队及3 000吨级单船自航上滩的临界流量显著提升。     

Hydraulic assessment of environmental flow regimes to facilitate fish passage through natural riffles: Shoalhaven river below Tallowa Dam,New South Wales,Australia

Proposed environmental flow regime changes downstream of a major water supply dam have been assessed in terms of effects on depth, velocity and fish passage across natural, gravel‐bed riffles and rapids. This study focussed on passage requirements for Australian bass, Macquaria novemaculeata (Perciformes, Percichthyidae), a catadromous fish of considerable ecological and recreational fishing importance. Some 23 major riffles and rapids occur between the dam and the tidal limit over a river length of 25 km. Reconnaissance investigations of riffle slope, length, width, depth and morphologic characteristics indicated that wide‐shallow, steep‐turbulent and bifurcating riffle morphologies were most likely to cause problems for upstream bass passage under low flow conditions. Two approaches were used to investigate riffle depths and velocities over a range of flows. A rapid assessment approach directly measured thalweg depths and velocities under two controlled flow release rates in riffles identified as being potentially problematic to upstream bass passage. Detailed topographic surveys and two dimensional hydraulic modelling with River2D was undertaken for two riffles identified as ‘worst case’ examples of wide‐shallow and steep‐turbulent morphologies. Results from both approaches were consistent and complementary. Both approaches identified riffles where minimum depths and maximum velocities were likely to be problematic for upstream passage by Australian bass at a flow rate of 130 MLd^?1 (the current regulated flow release) but were mitigated at flow rates above 300 MLd^?1. Assessment of environmental flow regime transparency and translucency threshold options with regard to a 300 MLd^?1 target flow indicated that options where the transparency threshold was set at the 80th flow duration percentile (flows equalled or exceeded for 80% of time), and varied according to the monthly pattern of natural flows, improved hydraulic conditions for upstream bass migration. Copyright © 2009 John Wiley & Sons, Ltd.     

三峡工程施工期库区航道治理

在三峡工程施工期，库区水位逐步抬高，航行条件有所改善，但由于水位抬高后，泥沙将产生累积性淤积，同时川江航道中礁石纵横，在蓄水位抬高的过程中，亦会出现新的碍航滩险，必须根据各类碍航滩险产生的原因，提出各类滩险的治理方案并付诸实施。     

Influence of artificial ecological floating beds on river hydraulic characteristics

The artificial ecological floating bed is widely used in rivers and lakes to repair and purify polluted water. However, the water flow pattern and the water level distribution are significantly changed by the floating beds, and the influence on the water flow is different from that of aquatic plants. In this paper, based on the continuous porous media model, a moveable two-layer combination model is built to describe the floating bed. The influences of the floating beds on the water flow characteristics are studied by numerical simulations and experiments using an experimental water channel. The variations of the water level distribution are discussed under conditions of different flow velocities（ v= 0.1 m/s, 0.2 m/s, 0.30 m/s, 0.4 m/s）, floating bed coverage rates（20%, 40%, 60%） and arrangement positions away from the channel wall（ D= 0 m, 0.1 m, 0.2 m）. The results indicate that the flow velocity increases under the floating beds, and the water level rises significantly under high flow velocity conditions in the upstream region and the floating bed region. In addition, the average rising water level value（ARWLV） increases significantly with the increase of the floating bed coverage rate, and the arrangement position of floating beds in the river can also greatly influence the water level distribution under a high-flow velocity condition（v ？0.2 m /s）.