Structure And Succession Of Phytoplankton Assemblages In Pumped Storage Reservoirs For Water Supply To Shenzhen City, China

Water diversion is an important way of filling water into reservoir, which directly orindirectly affects the hydrodynamic and physical and chemical parameters of pumpedreservoirs, and also influences the ecology of phytoplankton. This thesis investigated theseasonal dynamics of nutrients and hydrology of five pumped storage reservoirs in Shenzhen,and applied functional groups and multivariate analysis methods to explore the structures andsuccessions of the phytoplankton community and the key regulating factors.Dongjiang pumping station, Xizhijiang pumping station, Xili Reservoir, TiegangReservoir and Shiyan Reservoir are eutrophic; Xikeng Reservoir and Songzikeng Reservoirwere meso-eutrophic. Though there is a certain relationship of water quality between thereservoirs and their water sources, the diversion mode, hydraulic retention time, watershedmanagement, internal and external pollutions and other factors, which together determine thenutrient level of the reservoirs.2: The ecological characteristics of the reservoirs and pumping stations are well indicatedby the compositions and successions of phytoplankton community in functional groups.Functional groups of P, C, D, etc., belonging to diatom, often dominated in the Pumpedstorage reservoirs, reflecting strong water mixing and thermal instability, and weaksuccessions of phytoplankton community. Filamentous cyanobacteria, represented by S1andSNfunctional groups, were dominant in the wet season at high temperature in Tiegang andShiyan Reservoir, coinciding with high pH and low transparency of the two reservoirs; B andMP functional groups were dominant in Xikeng and Sozikeng Reservoirs, with low nutrientlevel and instability; phytoplankton community compositions in Dongjiang and Xizhijiangpumping stations changed dramatically, the domoniant function groups are MP, TB, Lo, P, Y.3：Multivariate analysis showed that WRT （Water retention time） is the most importantfactor affecting phytoplankton community in the five reservoirs and two pumping stations,followed by nutrient level, transparency, pH, temperature and other environmental parameters.WRT regulating by human, nutreint level and other environmental parameters, togetherdetermine the composition and succession of phytoplankton community.