Hydrodynamic modelling and shape optimisation of second-generation coastal reservoirs in consideration of algal bloom occurrence

Abstract Algal bloom has been a persistent problem for both fresh and marine water, with no exception coastal reservoir (CR). Among the algal mitigations CR, shape optimisation to reduce occurrence frequently mentioned. However, there was literature found on actual study or process CR. Thus, this research done bridge gap, particularly second-generation Hydrodynamic model of MIKE 21 used, secondary data obtained from published papers Google Earth. The critical velocity corresponding growth were only available cyanobacteria, chlorella , filamentous algae phytoplankton. Hence, these species considered in mapping. All models simulated eight idealised cases CR at Yangtze Estuary. These different geometric shapes analysed compared, considering several factors including average reservoir, presence stagnant percentage each so on. From results, “shorter piano key” ranked highest among all terms proneness bloom, based flow within reservoir. findings, further CRs. process, optimised “little dinosaur” pencil” showed excellent reduction blooming. preferred as its location is small controllable due “piano structure. Lastly, findings applied an existing Qingcaosha see if analysis can areas prone great area blooming compared original but addition structure did not have significant impact since highly dependent natural topography. study, it concluded that topographic-dependent should be case-by-case basis, following direction As without topographical constraints, by placing inlet perpendicular direction, minimising corners, implementing piano-key-like structure, optimising refer overall design.