滇池水华特征及成因分析

Characteristics of Blue Algal Bloom in Dianchi Lake and Analysis on Its Cause

滇池水华的规模大，持续时间长。水华的主要种类是蓝藻门的微囊藻属，其中以铜绿微囊藻占绝对优势。每年４～１１月为水华发生期，常在外草海南部、海埂、灰湾一带形成大面积水华，盛时可遍及全湖，水体表层藻类叶绿素含量高达５０００ｍｇ／ｍ３。滇池水体中高含量的Ｎ和Ｐ营养物在水华的形成中起着关键作用，适宜的温度及充足的光照为水华的频发提供了有利条件，并且随着滇池富营养化的加剧及水温逐年升高。

Algal bloom is characterized with large scale and a long lasting time in Dianchi Lake.The main species forming algal bloom is Microcystis and M.aeruginosa is the absolutely dominant species.Algal bloom occurs from April to November every year and usually distributes in Haigen,Hui Bay and the south part of Caohai,sometimes even all the lake.the maximum chlorophyll concentration of surface water reaches 5 000 mg/m 3.High content of N and P in the water of the lake is the main reason responsible for the algal bloom formation while suitable natural conditions also contribute to the process.