Discharge and water level fluctuations in response to flow regulation in impounded rivers: An analytical study

Yang, Zhongyong; Zhu, Yingying; Ji, Daobin; Yang, Zhengjian; Tan, Jing-He; Hu, Hao; Lorke, Andreas

doi:10.1016/j.jhydrol.2020.125519

Cited by 11 publications

(3 citation statements)

References 43 publications

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“…In recent decades, water-surface fluctuations in rivers and streams have garnered increased attention. Investigations have encompassed a wide range of topics, from studying water level fluctuations during the lock emptying process [16,17] and hydropower station operations [18] to examining the impact of spur dikes on riverbanks [19] and the presence of axisymmetric side cavities on water-surface oscillations in channels [20]. Additionally, researchers have explored the influence of periodic cylinder arrays (similar to vegetation) on flow dynamics and water-surface oscillations [21,22].…”

Section: Introductionmentioning

confidence: 99%

Analysis of Water-Surface Oscillations Upstream of a Double-Right-Angled Bend with Incoming Supercritical Flow

Elgamal,

Chaouachi,

Farouk

et al. 2023

Water

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This study deals with the free-surface supercritical flow through a double-right-angled bend (DRAB), which can be found in storm drainage networks in steep terrains. Laboratory experiments showed that strong backwater effects and water-surface oscillations are generated upstream of the DRAB, especially in supercritical flow conditions. This paper investigated the DRAB hydraulic behavior and water-surface heading up (backwater), and oscillations under supercritical flow conditions. Thirty-four lab experiments were conducted with Froude numbers ranging between 1.03 and 2.63. Dye injection and video analysis were used to visually capture the flow structure and to record water-surface oscillations. A tracker package was utilized to analyze the collected visual data. Time series and spectral analysis were used to identify the statistical characteristics of recorded water level time series and the dominant frequencies. It was found that the dominant frequencies of water-surface oscillations upstream of the DRAB range between 1.6 and 4.6 Hz with an average value of about 3 Hz. The Strouhal number of the water-surface oscillations is more sensitive to the Froude number than to the Reynolds number. The Strouhal number ranged between 0.03 and 0.3 for Froude numbers ranging from 2.63 to 1.03. The study confirms that near critical flow conditions exhibit the highest water oscillation, and that the maximum nondimensional water depth upstream of the DRAB is underestimated by both the Grashof formula and Knapp and Ippen (1939) model. A new formula is proposed to estimate the maximum water depth upstream of the DRAB.

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Section: Introductionmentioning

confidence: 99%

Analysis of Water-Surface Oscillations Upstream of a Double-Right-Angled Bend with Incoming Supercritical Flow

Elgamal,

Chaouachi,

Farouk

et al. 2023

Water

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“…Unsteady flow resulting from an abrupt change in the flow rate from hydraulic structures (e.g., pumping station, spillway, ship lock, etc.) impacts the stabilization of water supply system (Baghlani 2014) and also alters navigable flow conditions (Liu et al 2012;Zhang et al 2019;Yang et al 2020). The effects of dam discharge, hydropower unit regulations, lock operations, and other hub scheduling modes on the velocity, flow pattern, and surge in the channel are currently being investigated by domestic and international scholars using prototype observations, physical model tests, and numerical simulation techniques (Bravo & Jain 1991;Xue 1994;Stockstill et al 2004;Maeck & Lorke 2014;Shang et al 2017).…”

Section: Introductionmentioning

confidence: 99%

Effect of ship-lock-induced surges on navigation safety in a branched lower approach channel system

Wan

Wang

et al. 2022

Journal of Hydroinformatics

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Ships docking and traveling in a branched lower approach channel system are at risk from surges caused by multi-lane locks during emptying operations. For this reason, water-level variations in the lower approach channel in response to discharge, interval running time, and outlet location of lock operations were studied using a 2-D hydrodynamic model validated by physical model tests, and the impact of water level variation on navigation safety under extreme operation scenarios of a quadruple-lane lock group was identified. Results indicated that discharge and interval running time of lock emptying had the greatest impact on the water level variation at the lock head. Water level variation at the lower lock head of the ship lift exhibited a trend of first decreasing and then increasing with the increment of the discharge from the lock chamber into the outer river. Specifically, the surge height at the lock head of the ship lift reached the minimum when approximately 40% of the discharge generated by dual-lane locks during emptying operations was released into the outer river. Overall, the simultaneous operation of quadruple-lane lock group and unit load rejection should be avoided in engineering applications.

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“…Therefore, numerous studies have focused on water pollution under the conditions of WLFs 15 – 17 . Some scholars are concerned about the impact of water level fluctuations on the overall structure, hydrological characteristics, and macrophytes of lakes and rivers 18 – 22 . However, the relative effects of WLFs on individual biological species and communities are less clear than the effects of other physical and chemical variables.…”

Section: Introductionmentioning

confidence: 99%

Ecological adaptability and population growth tolerance characteristics of Carex cinerascens in response to water level changes in Poyang Lake, China

Yao

Cao

Zheng

et al. 2021

Sci Rep

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Water level conditions are the key factors that affect the growth and distribution of wetland plants. Using Carex cinerascens (C. cinerascens) as the study species, we employ indoor simulations and field surveys. Our results show that C. cinerascens can adapt to rhythmic changes in the water level through different adaptation strategies. Compared to that of the control group, plant growth was better with a 0–0.4 cm/d water level rate, and plant growth was in the 42–56 cm range to that a 1.0–1.4 cm/d water level rate. Furthermore, it was observed that 0–0.4 cm/d was the most suitable growth rate, with 0.6–1.0 cm/d and 0–32 cm being the ideal plant tolerance ranges, and increasing to 1.0–1.4 cm/d and 32–56 cm exceeds the plant tolerance threshold. In the middle and late period of the experiment (25–45 d), the ecological characteristics of the plants changed significantly. For example, the root-to-shoot ratio of the plant in the stable water level reached 26.1. In our field observations, plant biomass can be influenced by a variety of environmental factors. The frequency of the species was the largest at an elevation of 15 m, and the growth status of the dominant and companion species of C. cinerascens was weakened with an increase in soil moisture content. The suitable water content for C. cinerascens growth was 27.6–57.3%, the distribution elevation was 12.54–16.59 m, and the optimum elevation was 13.56–15.54 m. The study is expected to provide a reference for wetland ecology research and wetland protection and restoration, a theoretical reference for the coordination of water resource development and utilization of Poyang Lake and ecological protection of important lakes and wetlands, and an important scientific basis for wetland hydrologic regulation, ecological restoration and biodiversity conservation.

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Discharge and water level fluctuations in response to flow regulation in impounded rivers: An analytical study

Cited by 11 publications

References 43 publications

Analysis of Water-Surface Oscillations Upstream of a Double-Right-Angled Bend with Incoming Supercritical Flow

Analysis of Water-Surface Oscillations Upstream of a Double-Right-Angled Bend with Incoming Supercritical Flow

Effect of ship-lock-induced surges on navigation safety in a branched lower approach channel system

Ecological adaptability and population growth tolerance characteristics of Carex cinerascens in response to water level changes in Poyang Lake, China

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