南水北调东线湖群水体营养状态评价及其限制因子研究

The problem of lake eutrophication is an urgent issue faced in the protection of lakes in China. Conducting research on the evaluation of lake trophic status and its limiting factors is of great significance for the treatment of eutrophic lakes and the restoration of ecosystems. This research took the regulated lake group of the East Route Project of South-to-North Water Diversion - Gaoyou Lake, Hongze Lake, Luoma Lake, Nansi Lake, and Dongping Lake as the research area. In April 2018 during the non-water diversion period and in October during the water diversion period, a systematic monitoring was carried out on 109 sampling sites of the regulated lake group. The comprehensive trophic state index method was used to evaluate the trophic status of the regulated lake group, and multivariate statistical analysis methods were used to analyze the eutrophication characteristics and limiting factors of the lake group. The results showed that: within the same water period, the water quality indicators among the regulated lakes were not exactly the same. The water quality of each regulated lake during the non-water diversion period was better than that during the water diversion period, and the main factors affecting the compliance of water quality were total nitrogen and total phosphorus. During the water diversion period, the regulated lake group was in a slightly eutrophic state, and during the non-water diversion period, it was in a mesotrophic state, with the non-water diversion period being better than the water diversion period. Transparency and chlorophyll-a were the limiting factors determining the eutrophication level of the regulated lake group.

湖泊富营养化问题是我国湖泊保护面临的紧迫问题,开展湖泊营养状态评价及其限制因子研究,对于富营养化湖泊治理和生态系统修复具有重要意义。该研究以南水北调东线工程调蓄湖群-高邮湖、洪泽湖、骆马湖、南四湖、东平湖为研究区域,于2018年4月非调水期和10月调水期对调蓄湖群109个样点开展了系统监测,采用综合营养状态指数法对调蓄湖群营养状态进行了评价,运用多元统计分析方法分析了湖群富营养化特征及其限制因子。结果表明:同一水期内调蓄湖泊间水质指标不尽相同,各调蓄湖泊非调水期水质优于调水期,影响水质达标的主要因子为总氮和总磷。调蓄湖群调水期均处于轻度富营养状态,非调水期均处于中营养状态,非调水期优于调水期。透明度和叶绿素a是决定调蓄湖群富营养化水平的限制性因子。