Analysis on phosphorus pollution and eutrophication of the large reservoirs for water supply in Guangdong province

Investigation and monitoring on phosphorus pollution and eutrophication status of the large and medium reservoirs for water supply in Guangdong province were carried out in flood season and dry season of 2000. Among the 20 investigated reservoirs, half have been contaminated by phosphorus. So phosphorus pollution was one of the important causes that involved in eutrophication. The concentration of TP was consistent with the trophic state of the reservoirs. Phosphorus limitation phenomenon was common in the reservoirs, and it was more obvious in the dry season. Under low temperature and phosphorus limitation diatoms had more advantage than green algae.