Submerged aquatic vegetation (SAV) changes the turbulent structure of rivers, wetlands, estuaries, and lakes. However, few studies have focused on influence SAV hydrodynamic characteristics under wind-induced flow. Therefore, laboratory experiments were conducted to study effects flow turbulence flow, spectral based decomposition method was used separate wave velocity. Result shows that reduced local velocity within canopy elevates location zero-velocity point. The drag caused by increases...

On the basis of estimates sediment accumulation in reservoirs, impact 50,000 dams on supply and intertidal wetland response Yangtze River catchment is examined. The total storage capacity reservoirs 200 × 10 9 m 3 , or 22% annual runoff. rate has increased from ∼0 1950 to >850 6 t/yr 2003. Although yield with broader soil erosion river basin, riverine discharge shows a strong decreasing trend late 1960s 2003, likely due dam construction. Consequently, growth wetlands at delta front...

Abstract Uninterrupted records of annual discharge from the Yangtze River to sea (at Datong Hydrographical Station) began in 1950s. This series shows no significant trend. However, at Hankou, a station upstream Datong, discharges have been observed since 1865 almost without gaps. The and Hankou were found be closely correlated. Based on regression equation, missing estimated time 2004 was established. Although has varied greatly, it decreasing trendline revealed an 8.2% decrease 2004....

Abstract. The surface erosion area in the Yangtze River basin increased from 364×103 km2 1950s to 707×103 2001 due a great increase population. Based on regression relationship between and population, was predicted be about 280×103 at beginning of 20th century. sediment yield, which by 30% during first six decades century, closely related this river basin. annual suspended flux into estuary 395×106 t a-1 gradually an average 509×106 1960s. accelerated 1960s rapid population land use...

Abstract. Lake Dongting, the second largest freshwater lake in China and located middle reaches of River Yangtze catchment, was formed at beginning Holocene period by sea level rise has varied size with changes local weather patterns. The sedimentation rate Dongting during is about 50×106 m3 yr-1, or 80×106 t yr-1 (a sand bulk density 1.6×103 kg m-3), given sediment deposition as 10 mm average 5000 km2. By comparing import export, it estimated that 110.6×106 from 1956 to 2003. Siltation...

气流作为湖泊、湿地等有限水域的主要驱动力之一，其演化特征是研究水-气间能量与物质传递的基础，决定了水域水环境与水生态格局，具有重要研究意义.采用室内风洞水槽，通过设置不同试验风速，研究近水面气流与风速和吹程的响应关系与演化特征，并将光滑壁面条件下的气流特征作为试验对照组，分析时间域内风速垂向分布形式、摩阻风速、特征粗糙度等变化规律，剖析频率域内风速的主频变化与波致气流边界层厚度等参数的分布特征.结果表明：近水面时均风速符合对数分布，摩阻风速与特征粗糙度均与风速呈正相关，且同等风速与吹程条件下两者均大于光滑壁面条件，波致气流边界层厚度与风速和吹程均呈正相关.分析了采用风速作为气流动力参数存在不妥的原因，认为采用摩阻风速或切应力作为气流动力参数更具合理性，基于前人研究数据的统计分析，给出了特征粗糙度与风速、吹程和水深的回归关系式.探讨了气流-风浪“同频率”的互馈模式，发现波致气流边界层厚度不只与波长有关，还受波高、波周期和水深等多因素影响，建立了考虑风浪非线性特征的波致气流边界层厚度关系式.;As one of the main driving forces limited...

Based on the two-dimensional hydrodynamic model of finite volume method and structured multigrid, flow characteristics around a square cylinder with boundary constraint are analysed. The gap ratio G/D (G is distance from to channel boundary, D side length cylinder) does not change four patterns. Under laminar vortex street phase, only reduces scale vortices. centres pressed toward boundaries channel, low velocity zone formed near but law vorticity attenuation along direction changed. pattern...

Bathymetric data based on sounding surveys and intertidal elevations measured using Real-Time Kinematic Global Positioning System methodology were analyzed Geographical Information techniques to examine the morphological evolution of tidal island Jiu Duan Sha (JDS) in Yangtze estuary. It was found that, from 1958 2005, area sediment volume JDS increased by 96% 156% above 5 m isobath 331% 504% Lowest Astronomic Tide (LAT). Specifically, maximum elevation 0.3 4.9 LAT, salt marsh 0% 40% area....

Coherent vortex structures (CVS) are discovered for more than half a century, and they believed to play significant role in turbulence especially separated flows. An experimental study is conducted pressured backward-facing step flow with Reynolds number (Reh) being 4400 9000. A synchronized particle image velocimetry (PIV) system developed measurement of wider range velocity fields high resolution. The CVS proved exist the separation-reattachment process. For their temporal evolution, life...

The wind drag coefficient, Cd, has a great influence on the numerical results obtained from shallow lakes. To analyze modeling impacts of Cd wind-driven currents, series simulations Lake Taihu were conducted at three grid resolutions (800 m × 800 m, 400 and 100 m) using empirical formulae Flather (F76), Large Pond (LP81), Yeager (LY04), Andreas (A12), Gao (G20). G20 formula produced optimum all for both water level velocity simulations; however, resolution was found to have significant...

Climate change and human activities are having increasing impacts on the global water cycle, particularly streamflow. Current methods for quantifying these numerous have their merits limitations. There is a lack of guide to help researchers select one or more appropriate attribution analysis. In this study, hydrological modeling, statistical analysis, conceptual approaches were used jointly develop methodological options framework consisting three modules, in selecting assessing climatic...

Aquatic vegetation is one of the important parts shallow lake ecosystem, which has an impact on characteristics wind-driven wave and current. In this article, we embed module into flow model TELEMAC-3D TOMAWAC, respectively, construct coupling flow–wave–vegetation in open source Open TELEMAC-MASCARET. Through verification two sets experimental data, it been proven that can well reproduce influence current wave. Then, applied to simulation a typical lake, Taihu Lake. The results show...

Abstract Statistical and wavelet analyses are useful tools for analyzing river water quality parameters. In this study, they were employed to study parameters including biochemical oxygen demand (BOD), dissolved (DO), nitrate (NO3), ammonium (NH4), phosphate (PO4), total phosphorus (TP), Kjeldahl nitrogen (TKN), chlorophyll a (CHLA), suspended solids (TSS) temperature (TEMP) monitored at five hydrologic stations on the Lower Minnesota River, USA. Strong positive correlations observed between...

Abstract With the method of a wind tank experiment, real scenario lakes with horizontal and vertical circulation wind-induced flows is considered, features wave height its distribution in different conditions blowing distance, speed water depth are studied systematically. Afterwards, comparison distributions derived directly from experiment typical models show that some defects exist when describing growth stage. On this basis, we propose new model which suitable for description during...

Water environment pollution and water ecological degradation are the common problems in lake. As dynamic basis of lake system, hydrodynamics has a decisive influence on ecology. The numerical simulation is an important means to study characteristics hydrodynamics, For lakes driven by wind, drag force airflow usually represented wind coefficient ( Cd ). reflects momentum transfer efficiency between airflow, closely related wind，waves，flow their mutual feedback mode, most...

<title>Abstract</title> Submerged aquatic vegetation (SAV) changes the turbulent structure of rivers, wetlands, estuaries, and lakes. However, few studies have focused on influence SAV hydrodynamic characteristics under wind-induced flow. Therefore, laboratory experiments were conducted to study effects flow turbulence spectral based decomposition method used separate wave velocity. Result shows that reduced local velocity within canopy elevates location zero-velocity point. The drag caused...