Eutrophication Evaluation and Analysis on Its Influencing Factors of Erhai Lake

In order to examine the eutrophication status of Erhai Lake, through on-site investigation and data collection,the correlation between total nitrogen (TN), total phosphorus (TP), permanganate index (COD_Mn), total transparency (SD), chlorophyll a (chla) and total nutrient state index (TLI) and the influencing factors of eutrophication in Erhai Lake were studied. The results showed that TP, TN, COD_Mn, chla, TLI (∑) were increasing from 2008 to 2017. N and P were the main pollution factors. Chla, TN, TP, COD_Mn were positively correlated with TLI (∑). The comprehensive nutritional state index of Erhai Lake was growing. The trend of eutrophication was getting worse. Therefore, countermeasures must be taken to curb the worse of eutrophication.