Abstract
The ecological analysis of 31 algae and cyanobacteria indicators assessed the water quality of the Changchun drinking water Xinlicheng Reservoir by using bio-indication methods. The water was fresh, low alkaline, low-saline, middle oxygenated, with reached nutrients and organic pollution and mesotrophic to eutrophic. Statistics reveal significant variables that impacted algal diversity were nutrients, water quality was low to the middle polluted Class II-III. The indices of saprobity and WESI show the high self-purification capacity and low-toxicity impact. We revealed potential threatening species of cyanobacteria. The improving water quality from 2007 up to now has been revealed.