Effects of Selective Withdrawal on Temperature of Water Released of Glen Canyon Dam

Zhang, Shaoxiong; Gao, Xueping

doi:10.1109/icbbe.2010.5517675

Cited by 9 publications

(5 citation statements)

References 2 publications

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“…Thus, the data on withdrawn water temperature collected synchronously within 10 min were reliable and accurate. A comparison of withdrawn water temperature between the model test and numerical simulation (using EFDC) [ 18 ] is shown in Figure 8 . We could easily find that we correspond with each other.…”

Section: Derivation and Discussionmentioning

confidence: 99%

Similarity Theory of Withdrawn Water Temperature Experiment

Han

Gao

2015

The Scientific World Journal

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Selective withdrawal from a thermal stratified reservoir has been widely utilized in managing reservoir water withdrawal. Besides theoretical analysis and numerical simulation, model test was also necessary in studying the temperature of withdrawn water. However, information on the similarity theory of the withdrawn water temperature model remains lacking. Considering flow features of selective withdrawal, the similarity theory of the withdrawn water temperature model was analyzed theoretically based on the modification of governing equations, the Boussinesq approximation, and some simplifications. The similarity conditions between the model and the prototype were suggested. The conversion of withdrawn water temperature between the model and the prototype was proposed. Meanwhile, the fundamental theory of temperature distribution conversion was firstly proposed, which could significantly improve the experiment efficiency when the basic temperature of the model was different from the prototype. Based on the similarity theory, an experiment was performed on the withdrawn water temperature which was verified by numerical method.

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Section: Derivation and Discussionmentioning

confidence: 99%

Similarity Theory of Withdrawn Water Temperature Experiment

Han

Gao

2015

The Scientific World Journal

Self Cite

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“…Currently, most researchers employ simplified empirical formulas [7,8], indoor physical model tests scaled to certain proportions [9,10], and numerical hydrodynamic models, such as CE-QUAL-W2 [11,12] and EFDC [13,14] to investigate the relevant issues and assess the impact of water extraction from stoplog gates. These methods have guided the development of operational programs to some extent by calculating the discharge-water temperature (DWT), processed under certain representative operating conditions.…”

Section: Introductionmentioning

confidence: 99%

Assessment of Stoplog Gates’ Operational Effectiveness for Improving Discharged-Water Temperatures during the Thermal Stratification Period in a Reservoir

Liu,

Tuo,

Xia

et al. 2023

Water

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The discharge of low-temperature water from the middle and lower layers of thermally stratified dam reservoirs leads to thermal pollution and adversely affects fish production and reproduction in downstream rivers. Selective water withdrawal using stoplog gates is an effective approach to address this issue. However, comprehensively and effectively evaluating the effects of stratified withdrawal and optimizing the scheduling of stoplog gates to provide better ecological services to downstream habitats pose significant challenges for reservoir managers. In this study, an equivalent elevation method (EEM) was developed based on in situ observation data of water temperature. The EEM calculates the equivalent withdrawal elevation (EWE) in the far dam area corresponding to the discharge-water temperature (DWT), facilitating the evaluation of stoplog-gate effects. EEM was applied to a thermally stratified dam reservoir in southwestern China (Guangzhao reservoir, GZ). The results showed a significant positive correlation (r > 0.7, p < 0.05) between DWT and the vertical-water-temperature structure in the far dam area. The average EWEs for the 5-layer, 4-layer, and 3-layer stoplog gates in GZ were 697.2 m, 690.8 m, and 689.9 m, respectively. Utilizing the EEM findings, a scheduling operation scheme was proposed to improve DWT while reducing the number of stoplog-gate operations, thereby increasing their efficiency and saving the cost of invested labor and time. This method provides a reference for reservoir managers in optimizing stoplog-gate-scheduling strategies to mitigate potential risks to aquatic ecosystems caused by abnormal water temperature.

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“…Reservoirs with a single outlet might release water that is too warm or too cold for downstream ecosystems, depending on reservoir temperature at the intake [ 3 ]. Currently, considering the severe effect of bottom-intake for withdrawal on ecology [ 12 , 13 ], which was commonly employed in some north temperate countries in the 1960s, selective withdrawal systems have been widely used to meet downstream temperature and other water quality objectives [ 14 , 15 ], such as stoplog gates [ 16 ] and temperature-control curtains (TCCs) [ 17 ]. With the objective of water quality changing, applying a selective withdrawal facility to a certain reservoir involves many factors such as the improvement effect of outflow temperature, reservoir operation and management mode, economic investment, safety performance and so on [ 18 ].…”

Section: Introductionmentioning

confidence: 99%

Study on the effect of front retaining walls on the thermal structure and outflow temperature of reservoirs

et al. 2021

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The front retaining wall (FRW) is an effective facility of selective withdrawal. Previous research has not estimated the effect of FRWs on the thermal regimes of reservoirs and outflow temperature, which are crucial to reservoir ecology. For this purpose, taking the Dongqing Reservoir as a case study, a two-dimensional hydrodynamic CE-QUAL-W2 model was configured for the typical channel-type reservoir in the southwestern Guizhou Province, to better understand the influence of FRWs on the thermal structure and outflow temperature. The simulated data from January to September 2017 showed that FRWs can change the vertical temperature distribution during the stratification period, accelerate the upper warmer water release and thus decrease the strength of thermal stratification. The stratification structure changed from a single thermocline to double thermoclines in August. An FRW resulted in an average 11.8 m increase in the thickness of the hypolimnion and a 1.2°C decrease in the thickness of the thermocline layer. An FRW increased the outflow temperature by 0.4°C and raised the withdrawal elevation by 16 m on average. The longitudinal velocity increased compared with the non-FRW condition, while the maximum velocity position moved up. In addition, FRWs can continuously obtain surface warmer water without manual operation and have low investment and good construction conditions. This study can provide an available selective withdrawal idea for reservoirs with similar hydraulic conditions.

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Effects of Selective Withdrawal on Temperature of Water Released of Glen Canyon Dam

Cited by 9 publications

References 2 publications

Similarity Theory of Withdrawn Water Temperature Experiment

Similarity Theory of Withdrawn Water Temperature Experiment

Assessment of Stoplog Gates’ Operational Effectiveness for Improving Discharged-Water Temperatures during the Thermal Stratification Period in a Reservoir

Study on the effect of front retaining walls on the thermal structure and outflow temperature of reservoirs

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