scholarly journals Peer Review #2 of "Metabolism in a deep hypertrophic aquatic ecosystem with high water-level fluctuations: a decade of records confirms sustained net heterotrophy (v0.1)"

2018 ◽  
Keyword(s):  
Water Level ◽  
Peer Review ◽  
Aquatic Ecosystem ◽  
High Water ◽  
Water Level Fluctuations ◽  
High Water Level ◽  
Net Heterotrophy

Weekly dynamics of phytoplankton functional groups under high water level fluctuations in a subtropical reservoir-bay

2010 ◽  
Vol 45 (2) ◽  
pp. 197-212 ◽  
Author(s):  
Lan Wang ◽  
Qinghua Cai ◽  
Yaoyang Xu ◽  
Linghui Kong ◽  
Lu Tan ◽  
...  
Keyword(s):  
Water Level ◽  
Functional Groups ◽  
High Water ◽  
Water Level Fluctuations ◽  
High Water Level ◽  
Phytoplankton Functional Groups

scholarly journals Metabolism in a deep hypertrophic aquatic ecosystem with high water-level fluctuations: a decade of records confirms sustained net heterotrophy

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5205 ◽  
Author(s):  
Mayrene O. Guimarais-Bermejo ◽  
Martin Merino-Ibarra ◽  
Patricia M. Valdespino-Castillo ◽  
Fermín S. Castillo-Sandoval ◽  
Jorge A. Ramírez-Zierold
Keyword(s):  
Primary Production ◽  
Water Level ◽  
Ecosystem Respiration ◽  
Gross Primary Production ◽  
Secchi Depth ◽  
High Water ◽  
Water Level Fluctuations ◽  
Environmental Drivers ◽  
High Water Level ◽  
Production Layer

Long-term and seasonal changes in production and respiration were surveyed in the Valle de Bravo reservoir, Mexico, in a period during which high water-level fluctuations occurred (2006–2015). We assessed the community metabolism through oxygen dynamics in this monomictic water-body affected by strong diurnal winds. The multiple-year data series allowed relationships with some environmental drivers to be identified, revealing that water level-fluctuations strongly influenced gross primary production and respiratory rates. Production and respiration changed mainly vertically, clearly in relation to light availability. Gross primary production ranged from 0.15 to 1.26 gO2 m−2 h−1, respiration rate from −0.13 to −0.83 gO2  m−2 h−1 and net primary production from −0.36 to 0.66 gO2  m−2 h −1 within the production layer, which had a mean depth of 5.9 m during the stratification periods and of 6.8 m during the circulations. The greater depth of the mixing layer allowed the consumption of oxygen below the production layer even during the stratifications, when it averaged 10.1 m. Respiration below the production layer ranged from −0.23 to −1.38 gO2 m−2 h−1. Vertically integrated metabolic rates (per unit area) showed their greatest variations at the intra-annual scale (stratification-circulation). Gross primary production and Secchi depth decreased as the mean water level decreased between stratification periods. VB is a highly productive ecosystem; its gross primary production averaged 3.60 gC m−2 d−1 during the 10 years sampled, a rate similar to that of hypertrophic systems. About 45% of this production, an annual average net carbon production of 599 g C m−2 year−1, was exported to the hypolimnion, but on the average 58% of this net production was recycled through respiration below the production layer. Overall, only 19% of the carbon fixed in VB is buried in the sediments. Total ecosystem respiration rates averaged −6.89 gC  m−2 d−1 during 2006–2015, doubling the gross production rates. The reservoir as a whole exhibited a net heterotrophic balance continuously during the decade sampled, which means it has likely been a net carbon source, potentially releasing an average of 3.29 gC m−2 d−1 to the atmosphere. These results are in accordance with recent findings that tropical eutrophic aquatic ecosystems can be stronger carbon sources than would be extrapolated from temperate systems, and can help guide future reassessments on the contribution of tropical lakes and reservoirs to carbon cycles at the global scale. Respiration was positively correlated with temperature both for the stratification periods and among the circulations, suggesting that the contribution of C to the atmosphere may increase as the reservoirs and lakes warm up owing to climate change and as their water level is reduced through intensification of their use as water sources.

scholarly journals Community metabolism in a deep (stratified) tropical reservoir during a period of high water-level fluctuations

2014 ◽  
Vol 186 (10) ◽  
pp. 6505-6520 ◽  
Author(s):  
Patricia M. Valdespino-Castillo ◽  
Martín Merino-Ibarra ◽  
Jorge Jiménez-Contreras ◽  
Fermín S. Castillo-Sandoval ◽  
Jorge A. Ramírez-Zierold
Keyword(s):  
Water Level ◽  
High Water ◽  
Water Level Fluctuations ◽  
Tropical Reservoir ◽  
Community Metabolism ◽  
High Water Level

Numerical Simulation of Engineering Wave for Zhongzui Bay

2007 ◽  
Author(s):  
Xiejun Shu ◽  
Senhui Jiang ◽  
Ruijie Li
Keyword(s):  
Numerical Simulation ◽  
Water Level ◽  
Simulation Method ◽  
High Water ◽  
Wave Transformation ◽  
Return Periods ◽  
Engineering Construction ◽  
Wave Refraction ◽  
High Water Level ◽  
Mild Slope Equation

For providing a better shelter condition, it is necessary to build a breakwater in Zhongzui Bay. In order to know whether mooring area meets the requirement after engineering construction and compare the mooring area between solid breakwater and permeable breakwater, a numerical simulation method is used in the sheltering harbor of Zhongzui Bay. The used Mild-slope equation which describes wave refraction, diffraction and reflection, considers the steep slope bottom and effect of energy dissipation. It has been validated to fit for simulating wave transformation in the coastal zone. Under extreme high water level and design high water level, wave fields in the calculation area of three wave types in three different return periods are simulated by using this method respectively. In addition, wave height in front of breakwater can be provided. Then the wave parameters and the mooring area of two occasions, with and without breakwater, are gained in calculation area. Based on these results, some conclusions are presented in the end.

scholarly journals The influence of Three Gorges Reservoir high water level on the rainfall runoff

2018 ◽  
Vol 246 ◽  
pp. 01007
Author(s):  
Biqiong Wu ◽  
Wei Zheng ◽  
Xinkai Ren ◽  
Tao Xu ◽  
Xiao Guo
Keyword(s):  
Water Level ◽  
Three Gorges Reservoir ◽  
Reference Value ◽  
High Water ◽  
Three Gorges ◽  
Rainfall Runoff ◽  
Flood Peak ◽  
High Water Level ◽  
Three Gorges Region ◽  
Unit Hydrographs

After Three Gorges Reservoir building up, the natural river course and the near hillside inside the backwater region are inundated to form a fairly wide man-made lake which affects the hydrological characteristics and floodwater transmission to different degrees. When the reservoir impound to high water level, the conflux time is obviously shortened, the flood-peak discharge increase, and the peak type became sharper. The change of runoff yield and concentration makes the forecast scheme unable to be applied well. Based on the practice of Three Gorges Reservoir operation, the rainfall-runoff characteristics of the backwater region under the condition of high water level are analysed and summarized, then a set of unit hydrographs suitable for rainfall-runoff calculation are recalibrated, which has great reference value for hydrological forecasting of Three Gorges region.

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