Abstract:

In order to make clear the nutrient salts distribution and trophic state in the Weishan Lake, the spatial distribution of nutrients in Weishan Lake was analyzed based on the monitoring data in April in 2010; Carlson trophic state index and potential eutrophication evaluation were applied to evaluate the eutrophic state of Weishan Lake. The results indicated that TP, P-PO4, TN, N-NO3, N-NO2, N-NH4 and chlorophyll a content in entryway portion>sea-route portion>breed portion; SD in sea-route portion>entryway portion>breed portion. The average Carlson trophic state indices in entryway portion, sea-route portion and breed portion were 63.0, 61.8 and 52.0 respectively; All of the three portion of the lake had reached or been close to eutrophication level. Potential eutrophication evaluation was used to evaluate trophic level, and the results showed that excepting S1 belonged to eutrophication level and S5 belonged to phosphorus moderate limit，all other stations belonged to phosphorus limit potential eutrophication level.