model for fixed algae management in open channels using flushing flows

• Published in: River research and applications Vol. 28; no. 7; pp. 960 - 972
• Main Authors: Fovet, O, Belaud, G, Litrico, X, Charpentier, S, Bertrand, C, Dollet, P, Hugodot, C
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01-09-2012; Wiley; John Wiley and Sons Ltd
• Subjects: Algae; algae detachment model; Animal and plant ecology; Animal, plant and microbial ecology; benthic algae; Biological and medical sciences; biomass production; Environmental Sciences; Fresh water ecosystems; Fundamental and applied biological sciences. Psychology; hydraulic flush; hydrodynamics; open channels; rivers; shear stress; Synecology; water quality; Hydraulics; open channels; Algae; algae detachment model; Shear stress; benthic algae; Models; Benthic zone; hydraulic flush
• ISSN: 1535-1459; 1535-1467
• DOI: 10.1002/rra.1495

The management of regulated rivers and canals involves new objectives of water quality preservation. Among water quality aspects, the development of benthic algae induces impacts on both the quantitative and the qualitative management. In open‐channel networks, their growth causes accumulation of biomass on the substratum, which decreases the hydraulic performance. Their detachment induces increases of drift biomass and particles likely to cause clogging issues. To manage these benthic algae developments, we study an original strategy that consists of performing hydraulic flushes in order to detach a part of the algal cover. The principle is to create a controlled hydrodynamic perturbation thanks to hydraulic control structures and to limit the quantity of fixed and drift algae simultaneously. We propose a comprehensive model of the flushes based on coupled hydrodynamic and algae detachment models in order to analyse and improve the management procedure. This model was applied on two real canals located in southern France.