Analysis of Water Quality on Urban Rivers and Lakes in Beying

Abstract

调研结果显示,2003年北京城区河湖(11个监测水体)总磷、总氮含量分别为0.142mg/L、1.481mg/L,已达到比较严重的富营养状态.北京城市河湖属于藻型水体,初级生产力主要决定于浮游藻类的群落结构与密度.河湖水体中浮游藻类密度为37867.82×10⁴ cells/L,其群落由蓝藻(Cyanophyta)、绿藻(Chlorophyta)、硅藻(Bcillariophyta)、甲藻(Pyrrophyta)、隐藻(Cryptophyta)、黄藻(Xanthophyta)、金藻(Chrysophyta)和裸藻(Eugleniphyta)构成.群落中蓝藻占绝对优势 (89.54%).在近几年的夏秋季连续发生程度不同的微囊藻(microcystis)水华,对水体功能和城市景观造成了不良影响.主要原因是:(1)氮磷和有机物的污染,(2)给城市河湖补给的水量少,(3)河湖生态系统被损害,水体自净能力差.本文对如何改善北京城市河湖水质提出了建议.;The research results indicate that total phosphorus and total nitrogen of urban rivers and lakes in Beijing had been attained separately 0.142mg/L and 1.481mg/L in 2003. The water bodies belonged to hyper-trophic type. The primary production was determined by community structure and cells density of phytoplankton. The urban rivers and lakes in Beijing were a water body of algal type. Phytoplankton cells density were 37867. 82×10⁴/L and the community were constructed by Cyanophyta, Chloriphyta, BacilIariophyta, Cryptophytav Xanthophyta, Eugleniphyta, Pyrrophyta and Chrysophyta. 89.54% was blue-green algae in phytoplankton cominunity. The water bloom of blue-green algae had taken place continuously in summer and autumn in recent years. Its influence was not good to function of water body and city view. The primary factor was:(1) pollution of nitrogen, phosphorus and organic material; (2) water quantity to supply the rivers and lakes were short; and (3) the ecosystem of urban rivers and lakes were changed and self-cleaning capacity was reduced seriously. The proposal to improve water quality of urban rivers and lakes in Beijing were advanced in the paper.