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)

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/

Figures

References:

[1]	Ji, D., et al., Impacts of water level rise on algal bloom prevention in the tributary of Three Gorges Reservoir, China. Ecological Engineering, 2017. 98(Supplement C): p. 70-81.
[2]	Ma, J., et al., Modeling density currents in a typical tributary of the Three Gorges Reservoir, China. Ecological Modelling, 2015. 296(Supplement C): p. 113-125.
[3]	Yang Z J, L.D.F., Ji D B, , Influence of the impounding process of the Three Gorges Reservoir up to water level 172.5 m on water eutrophication in the Xiangxi Bay. Science China Technological Sciences, 2010. 53: p. 1114-1125.
[4]	Yang, Z., et al., An eco-environmental friendly operation: An effective method to mitigate the harmful blooms in the tributary bays of Three Gorges Reservoir. Science China Technological Sciences, 2013. 56(6): p. 1458-1470.
[5]	Benjamin, T.B., Gravity currents and related phenomena. Journal of Fluid Mechanics, 1968. 31(2): p. 209-248.
[6]	Ashida, K. and S. Egashira, Basic study on turbidity currents. Vol. 1975. 1975. 37-50.
[7]	Kao, T.W., Density Currents and Their Applications Journal of the Hydraulics Division, 1977. 103 (5): p. 543-555.
[8]	R. L. Doneker; J. D. Nash; and G. H. Jirka, Pollutant Transport and Mixing Zone Simulation of Sediment Density Currents. Journal of Hydraulic Engineering 2004. 130(4): p. 349-359.
[9]	Asaeda, T., et al., A new technique for controlling algal blooms in the withdrawal zone of reservoirs using vertical curtains. Ecological Engineering, 1996. 7(2): p. 95-104.
[10]	Imteaz, M.A. and T. Asaeda, Artificial mixing of lake water by bubble plume and effects of bubbling operations on algal bloom. Water Research, 2000. 34(6): p. 1919-1929.
[11]	Asaeda, T., et al., Control of algal blooms in reservoirs with a curtain: a numerical analysis. Ecological Engineering, 2001. 16(3): p. 395-404.
[12]	H. S. Lee, S.W.C., J. K. Choi & B. H. Min, Feasibility of curtain weir installation for water quality management in Daecheong Reservoir. Desalination and Water Treatment 2010. 19: p. 164-172.
[13]	Priyantha, D.G.N., et al., Modelling effects of curtain method on algal blooming in reservoirs. Ecological Modelling, 1997. 98(2): p. 89-104.
[14]	Se-Woong Chung, H.L.a.Y.J., The effect of hydrodynamic flow regimes on the algal bloom in a monomictic reservoir. Water Science & Technology 2008. 58(6): p. 1291-8.
[15]	Yang, Z., et al., An eco-environmental friendly operation: An effective method to mitigate the harmful blooms in the tributary bays of Three Gorges Reservoir. Science China Technological Sciences, 2009. 56(6): p. 1458-1470.
[16]	Berger, C.J., Wells, S.A.,, Modeling the effects of macrophytes on hydrody- namics. J. Environ. Eng., 2008. 134 (9): p. 778-788.
[17]	Wells, S., Wells, V., Berger, C., Impact of Phosphorus Loading from the Watershed on Water Quality Dynamics in Lake Tenkiller. ASCE, 2012: p. 888–899.
[18]	Dias, F. and J.-M. Vanden-Broeck, Open channel flows with submerged obstructions. Journal of Fluid Mechanics, 2006. 206(-1).
[19]	Sverdrup, H.U., On conditions for the vernal blooming of phytoplankton. ICES Journal of Marine Science, 1953. 18(3): p. 287-295.
[20]	Helfer, F., H. Zhang, and C. Lemckert, Modelling of lake mixing induced by air-bubble plumes and the effects on evaporation. Journal of Hydrology, 2011. 406(3): p. 182-198.
[21]	Sambuco, E. and J.A. Whitehead, Hydraulic control by a wide weir in a rotating fluid. Journal of Fluid Mechanics, 2006. 73(03).
[22]	Akiyama, J., and Stefan, H. G., Theory of Plunging Flow into a Reservoir. ASCE, 1984. 110(4): p. 484-499.
[23]	Akiyama Juichiro, J.A.K., Yamasaki Tsutomu, Flow Characteristics of Surface Currents and Mixing by Curtains. Doboku Gakkai Ronbunshuu 2002. B 46: p. 1025-1030.
[24]	Akiyama Juichiro, J.A.K., YAMASHITA Naoki, URA Masaru, Control of Plunge Flows in Reservoir by Curtains for Countering Freshwater Red-Tide Blooms. Doboku Gakkai Ronbunshuu 2002. 46: p. 1013-1018.
[25]	Chung, S.W.L., H. Jung, Y., The effect of hydrodynamic flow regimes on the algal bloom in a monomictic reservoir. Water Sci Technol, 2008. 58(6): p. 1291-8.
[26]	Reynolds, C.S., The intermediate disturbance hypothesis and its applicability to planktonic communities: Comments on the view of Padisak and Wilson. New Zealand Journal of Ecology 1995. 19(2).
[27]	Connell, J.H.a.R.O.S., Mechanisms of succession in natural communities and their role in community stability and organization. The American Naturalist 1977. 111(982): p. 1119-1144.