Modeling Effects of Bottom Curtain Weirs and Controlling Algal Blooms in Xiangxi Bay, Three Gorges Reservoir, China

Ranojit Kumar Dutta^{1, 2,} , Jun Ma^{1, 3}, Baishakhi Das⁴ and Defu Liu^{1, 3}

¹College of Hydraulic & Environmental Engineering, China Three Gorges University, Yichang, 443002, Hubei, China

²Faculty of Science and Engineering, City University, Dhaka 1216, Bangladesh;Faculty of Engineering, Bangladesh University of Engineering and Technology (BUET), Dhaka-1000, Bangladesh

³Hubei Key Laboratory of Ecological Restoration of River-lakes and Algal Utilization, Hubei University of Technology, Wuhan 430068, China

⁴International Relations, Department of Political Science, NU, Bangladesh

Cite this paper

Ranojit Kumar Dutta, Jun Ma, Baishakhi Das and Defu Liu. Modeling Effects of Bottom Curtain Weirs and Controlling Algal Blooms in Xiangxi Bay, Three Gorges Reservoir, China. American Journal of Water Resources. 2019; 7(2):50-57. doi: 10.12691/AJWR-7-2-2

Abstract

A bottom curtain weir (BCW) is a hydraulic structure that acts as a barrier to the flow and diffusion of heat across the width of a water body. Algal blooms occur frequently in the largest tributary of Xiangxi Bay (XXB) of the Three Gorges Reservoir (TGR). A laterally averaged two-dimensional hydrodynamic and water quality model was used to simulate BCWs, including water temperature, hydrodynamics and chlorophyll-a concentrations, for XXB. The numerical models show that BCWs are a much more attractive, much less expensive and time-saving algal bloom controlling technique for subtropical reservoirs. The developed model was calibrated using data collected in XXB from January to December 2010. The maximum chlorophyll-a concentrations observed were 125-154 mg/m³ according to sampling sites such as XX09, XX06 and XX01. Overall chlorophyll-a concentrations were markedly reduced by 4-44% as a function of BCWs height and location. A seasonal algal bloom reduction rate of more than 37% was observed in summer. In some periods, such as May 27-31, June 2-4, June 16-18, August 16-18 and August 23-24, BCWs with heights of 3 m, 5 m and 7 m reduced algal blooms by up to 99% at XX09 and XX06 in XXB. Therefore, the proposed BCWs can reduce algal blooms and improve water quality to save domestic water and aquatic ecosystems in XXB of TGR.

Keywords

Three Gorges Reservoir (TGR), Xiangxi Bay (XXB), algal blooms, CE-QUAL-W2, Bottom Curtain Weirs (BCWs)

Copyright

This work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

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