Modeling Effects of Floating Curtain Weirs and Controlling Algal Blooms in a Subtropical Reservoir of 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 Floating Curtain Weirs and Controlling Algal Blooms in a Subtropical Reservoir of China. American Journal of Water Resources. 2019; 7(2):42-49. doi: 10.12691/AJWR-7-2-1

Abstract

Algal blooms occur frequently in Xiangxi Bay (XXB), which is one of the largest tributaries of the Three Gorges Reservoir (TGR). Floating curtain weirs (FCWs) are hydraulic structures that act as a barrier to divert density currents and diffuse heat across the width of the water body. Numerical modeling of FCWs is become a widely accepted method for controlling algal blooms. A laterally averaged two-dimensional hydrodynamic and water quality model (CE-QUAL-W2) was used to simulate the effects of FCWs, including those on water temperature, hydrodynamics and chlorophyll-a concentrations, for XXB. The developed model was calibrated using data collected in XXB from January to December 2010. The results indicated that the maximum chlorophyll-a concentrations observed were 74-154 mg/m³ at the XX09, XX06 and XX01 sampling sites. The performance of the FCWs suggests that the overall chlorophyll-a concentrations are markedly reduced by more than 85% as a function of the FCW heights and locations. Seasonally, an algal bloom reduction rate of more than 62% was observed in the summer. FCWs with heights of 3, 5, and 7 m reduced algal blooms by up to 99% at XX09 during March 26-28, April 24-27, July 18-26, August 5-20, and 23-28, and September 3-8 and 12-16, respectively. Therefore, the proposed FCWs can reduce algal blooms and improve water quality to save domestic water and aquatic ecosystems in XXB.

Keywords

Modeling effects, Floating curtain weirs (FCWs), Xiangxi Bay (XXB), Algal blooms, CE-QUAL-W2 model, Three Gorges Reservoir (TGR)

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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