Honghu Lake is the largest lake type wetland in Hubei Province, China. It is also one of the largest shallow lakes in the Yangtze River Economic Zone, a key area in the relatively more developed southeast China. However, the water quality saw to a deterioration tendency in the recent decades, mostly owing to unreasonable human activities such as lake enclosure aquaculture following the rapid social and economic development. Based on the water quality index (WQI) method, the water quality of Honghu Lake by vast data collected from five observation sites monitoring for over 10 years was analyzed and evaluated. The results show that: (i) The water quality of Honghu Lake is in the ‘General’ grade as a whole with a WQI value of 43.41 ± 6.66; (ii) The water quality has been improving in the recent two years, reversing its decade-long deterioration; (iii) The water quality sampled at Lantian site is the worst while that of Guandun site is the best; (iv) The concentration of Pb and (Cd) are the key parameters to determine the water quality of Honghu Lake. Therefore, it could be concluded that more attention should be paid to investigate heavy metals in Honghu Lake in the future.
The water quality index (WQI) method is a very effective method to evaluate water quality in lakes.
Water quality of Honghu lake, the largest lake wetland in the Hubei Province of China and one of the largest lakes in the Yangtze River Economic Zone as well, was analyzed and evaluated in the recent 10 years.
After going through a decade-long increasing deterioration, the water quality tends to be improved in the recent two years in the Honghu lake.
The concentration of Pb and the Cd are the key parameters to determine the water quality of the Hong Lake.