Analyses on water quality and trophic status of urban lakes in Nanjing city

Urban lakes locate in city area or non-agricultural towns, which are very important to city ecosystem and habitation environment. In this paper, nine lakes of Nanjing city (Huashen Lake, Baijia Lake, Yueya Lake, Mochou Lake, Nanhu Lake, Pipa Lake, Qianhu Lake, Zixia Lake, and Xuanwu Lake) were selected and water samples were collected seasonally, so as to analyze water quality and trophic status. Results showed that two lakes were mesotrophic, three lakes were light eutrophic, three lakes were medium eutrophic, and even one lake was heavy eutrophic. Finally, special needs to be pointed out as follows: strict control of phosphorus concentration in Zixia Lake should be strengthened to avoid blooms occurrence; obvious swamping trends were observed in Pipa Lake, where clearing and dredging were needed; eutrophic conditions were quite serious in Mochou Lake, Nanhu Lake, and Yueya Lake, comprehensive restoration was required in these three lakes timely.