Abstract: In coastal areas short of fresh water resources, pumped- and non-pumped type reservoirs play an important role in both urban and rural drinking water supply. In order to understand the eutrophication characteristics of these reservoirs, three pumped type reservoirs and three non-pumped type reservoirs were investigated in April, August, and December 2006. In pumped type reservoirs, the mean concentrations of total nitrogen, total phosphorus, and chlorophyll a were higher than those in non-pumped type reservoirs, but the mean Secchi disk depth was lower than that in non-pumped type reservoirs. In pumped type reservoirs, the concentrations of total nitrogen, total phosphorus, and chlorophyll a were higher in winter and spring than summer; while in non-pumped type reservoirs, they were in adverse. The phytoplankton biomass was slightly higher in pumped than in non-pumped type reservoirs. The seasonal dynamics of the dominant phytoplankton species were different in the two types of reservoirs. Pseudanabaene sp., Microcystis aeruginosa, and Aulacoseira granulate were dominant in pumped type reservoirs, while Peridinium sp. dominated in non-pumped type reservoirs. The eutrophication index of pumped type reservoirs was higher than that of non-pumped type reservoirs. PCA showed that nutrient was the dominating factor affecting the eutrophication in pumped type reservoirs, while temperature was the dominating factor in non-pumped type reservoirs. Pumping water into reservoirs modified the nutrients concentration and hydrologic process in pumped type reservoirs, leading to a significant difference in the eutrophication degree between pumped and non-pumped type reservoirs, and also, different seasonal patterns of eutrophication.

Key words: Remote sensing, Land cover classification, Fuzzy ARTMAP, Xianghai Nature Reserve