Assessment of Water Transfer Effects on Water Quality of Jihongtan Reservoir Based on the Dynamic Changes of Phytoplankton
The Jiaodong Water Transfer Project is a large-scale water resource allocation project in Shandong Province,with a long distance,cross-basin,and cross-regional nature.It implements a joint scheduling of water from the Yangtze River,Yellow River,and local reservoirs,and is an important water resource protection and configuration project in the Jiaodong region.In order to assess the water quality risks arising from interreservoir water transfer of the Jiaodong Water Diversion Project,five sample sites of the Xiashan and Jihongtan reservoirs were deployed for annual monthly and cryptic monitoring of phytoplankton,and the composition,abundance,community structure,dominant species,shared species and diversity in this two reservoirs were compared and analyzed during water diversion.The results showed that the phytoplankton in two reservoirs tended to be homogenized due to the diversion of water from Xiashan reservoir to Jihongtan reservoir,and multiple dominant Cyanobacteria species headed by Pseudanabaena sp.had good adaptability in Jihongtan reservoir,resulting in a decrease in phytoplankton diversity and a serious impact on community structure.The water quality of the Jihongtan reservoir changed rapidly from clean or oligopollution type to heavy pollution type.The water transfer management department should pay close attention to the change of phytoplankton and water quality status of the water sources and the receiving reservoirs,and choose the suitable water sources,the best seasons and the appropriate amount of water to carry out ecological water transfer as far as possible to ensure the water quality safety of the receiving reservoirs.