The quality of 13 major urban landscape waters in Xian was continuously monitored from December 2014 to June 2015, and its eutrophication situation and causes were analyzed. Results showed that Chl a was 1.13 mg/m3~675 mg/m3, TP was 0.012 mg/L~3.12 mg/L, TN was 0.271 mg/L~25.6 mg/L, SD was 0.17 m~1.77 m. By comparing different supplemental water sources and water quality, it showed that the nutrients content of tap water was the lowest, then natural surface water, and reclaimed water was the highest. The assessment of waters trophic state by trophic state index showed that about 68% of the landscape waters were eutrophicated. Five main causes of eutrophication in turn were nutrients index, physical and chemical indexes, organics indicators, sensory properties index and trace elements indicators. |