[Spatiotemporal Succession Characteristics of Algal Functional Groups and Its Impact Factors for a Typical Channel-Type Reservoir in a Southwest Mountainous Area].

In order to explore the spatial and temporal variations of algal functional groups in the Zipingpu reservoir, a typical channel-type reservoir in the southwest mountainous area of China, water samples were collected from eight sections of the Zipingpu reservoir from April 2016 to March 2017.A total of 21 algal functional groups were identified as B, C, D, F, G, H1, J, L0, LM, MP, N, P, S2, T, W1, W2, X1, X2, X3, Y, and Z. Based on the analysis of the dominant degree (y > 0.02), the algal functional groups were dominated by W2, Y, L0, W1, MP, and B. The C-R-S strategy of algal growth in the Zipingpu reservoir showed that R-type was a more dominant type than the S- and C-type for the majority of the time. Peridinium (group L0, type S) was the significant algae in the Zipingpu reservoir algal bloom event in June 2016.Redundancy analysis (RDA) was used to explore the relationship between algal functional groups and environmental factors. The results showed that algal density, chlorophyll a, water temperature, and biochemical oxygen demand were the major factors influencing the spatiotemporal succession of algal functional groups across the eight sampling sections, with water temperature having the highest influence.

Effect of hydrodynamic characteristics on reaeration process.

The equilibrium-perturb technique was used in the flume reaeration experiment. The interfacial mass transfer coefficients of DO were obtained by implementation of the oxygen-flux theory in the study. The turbulence characteristics of the flow field were investigated by numerical simulation approach. The expression of interfacial mass transfer coefficient related with velocity and turbulence kinetic energy was built. Examination with the experimental datum of different cases showed the validation of the expression.