太湖蓝藻水华暴发机制与控制对策

Mechanism and control strategy of cyanobacterial bloom in Lake Taihu

湖泊蓝藻水华暴发由于引发水生态系统的灾害和饮用水安全风险而成为国内外研究的热点之一.太湖蓝藻水华暴发原因多样,其中蓝藻自身的特性是水华暴发的内因,太湖的地理、水文和气象特征为蓝藻水华暴发提供了合适的温度和水动力条件,是蓝藻水华暴发的外因,湖泊草-藻型生态系统的转变以及氮、磷营养盐的高负荷输入更利于蓝藻生长,湖泊氮、磷营养盐四重循环是蓝藻水华不断暴发的维持机制,蓝藻水华暴发与氮、磷营养盐浓度之间存在交互作用关系.太湖蓝藻水华的控制应以陆源控源截污为基础,增加湖泊营养盐输出为重点,实现疏堵有机结合,其中恢复水生植被,重建草-藻结合型水生态系统是太湖湖泊生态修复的关键所在.

Cyanobacterial bloom has become the focus of all over the world because of its ecological risk and drinking water crisis.There are many reasons contribute to the cyanobacterial bloom in Lake Taihu.The characteristic of cyanobacteria themselves is the internal causes.As a subtropical shallow lake,Lake Taihu provides suitable temperature and hydrodynamic condition for the cyanobacterial bloom due to its geographical and hydrological meteorological characteristics.The shift from grass-shaped to algae-shaped ecosystem and the input of high load nitrogen and phosphorus nutrients are beneficial to the growth of cyanobacteria.In addition,the quadruple cycle of nitrogen and phosphorus intensifies cyanobacterial bloom.Cyanobacterial bloom interacts aqueous nitrogen and phosphorus concentrations.In order to control bloom in Lake Taihu,we should increase the output of nutrients based on cutting off the source of nitrogen and phosphorus.Above all,it is the key of ecological restoration of Lake Taihu to sequester and strengthen the recovery of macrophytes so that the macrophytic and algal ecosystems can be reconstructed.