title: [Elementary quantitative study on factors of phytoplankton bloom].
abstract: This study investigated the effect quantitatively on phytoplankton population by various factors such as sinking velocity, diffusivity, growth, mortality and water depth, through both numerically and theoretical methods, then proposed an initial judgment criterion for estimating phytoplankton population development. To the conventional simplification about even growth rate and vertical turbulent diffusivity, which is not consistent with the fact, this study investigated the influence by the asymmetric growth rate, as a result of light attenuation and nutrient limit, and uneven vertical turbulent diffusivity. It was shown that the 'shade effect' by light attenuation and nutrient flux limit both led. phytoplankton population from blooming or collapsing to quasi-steady condition. The uneven vertical turbulent diffusivity influenced the phytoplankton population by l/H which is upper euphotic layer depth by water depth. The influence is not apparent only if the water depth is large enough while l/H is small. Hence even vertical turbulent diffusivity can be utilized approximately in very shallow lakes.
authors.affiliation: School of Geographical Science, Nanjing Normal University, Nanjing 210046, China. mercury1214@126.com
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Zhang
authors.forename: Zhi-Yao
authors.initials: ZY
authors.lastname: Song
authors.forename: Chang-Chun
authors.initials: CC
authors.lastname: Huang
authors.forename: Zhao-Yuan
authors.initials: ZY
authors.lastname: Yu
mesh_terms: D017753:Ecosystem; D005068:Eutrophication; D008027:Light; D008962:Models, Theoretical; D009716:Numerical Analysis, Computer-Assisted; D010839:Phytoplankton / Q000254:growth & development*; D011157:Population Dynamics; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D014874:Water Pollutants, Chemical; D014867:Water