水库型水源地浮游植物不同种类季节演替动态模拟研究

Dynamic simulation on seasonal succession of different species of phytoplankton in reservoir-type water source

针对水库型水源地——金泽水库运行初期的水生态环境特点并结合浮游植物调查结果,基于Mike3软件的Ecolab模块二次开发,构建了可描述硅藻、蓝藻、绿藻3种不同藻类以及沉水植物、浮游动物、碎屑等在水体中相互作用过程的生态动力学模型,模型经验证与实测资料吻合较好。对不同种类浮游植物随季节的动态变化过程进行模拟,结果表明:金泽水库运行初期浮游植物不同种类季节演替表现为春季以硅藻、绿藻为主,8—9月蓝藻大量增殖,10月蓝藻生物量快速回落后以绿藻和硅藻为主的特点;浮游植物生物量在春季(4—5月)和秋季(8—9月)有两个峰值,且春季峰值高于秋季,冬季生物量最低,温度是影响金泽水库浮游植物群落生消演替的重要环境因子。浮游植物生物量的空间分布表明,不同库区的流速和光照条件差异对浮游植物群落的空间分布起到重要的作用,同时,库区沉水植物和浮游植物生长的竞争关系以及沉水植物的克藻效应有效抑制了浮游植物的增殖。

According to the characteristics of the water ecological environment in the early stage of the operation of Jinze Reservoir,a reservoir-type water source,and combined with the phytoplankton survey results,an ecological dynamic model was constructed on the basis of secondary development of Ecolab module of Mike3 to describe the interaction process of three different algae,such as diatoms,cyanobacteria,and green algae,as well as submerged plants,zooplankton,detritus,etc.The model was verified to be in good agreement with the measured data.The simulation of the seasonal dynamics of different phytoplankton populations show that the seasonal succession of different species of phytoplankton during the initial operation of the Jinze Reservoir is dominated by diatoms and green algae in spring,and cyanobacteria proliferated in large quantities in August and September,and in October,when the biomass of cyanobacteria drops rapidly,it is dominated by green algae and diatoms.Phytoplankton biomass has two peaks in spring(April and May)and autumn(August and September),and the peak in spring is higher in autumn,and the biomass in winter is the lowest.Temperature is an important environmental factor affecting the succession of phytoplankton community in the Jinze Reservoir.The spatial distribution of phytoplankton biomass show that the differences in flow velocity and light conditions in different reservoir areas play an important role in the spatial distribution of phytoplankton communities.At the same time,the growth competition between submerged plants and phytoplankton in the reservoir area and the algae-killing effect of submerged plants effectively inhibit the proliferation of phytoplankton.