Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, China University of Geosciences, Wuhan, 430074, China.
Hubei Key Laboratory of Regional Ecology and Environmental Change, School of Geography and Information Engineering, China University of Geosciences, Wuhan, 430074, China.
Environ Sci Pollut Res Int. 2022 Jul;29(35):53831-53843. doi: 10.1007/s11356-022-18519-1. Epub 2022 Mar 15.
Water quality deterioration and eutrophication of urban shallow lakes are global ecological problems with increasing concern and greater environmental efforts. In this study, spatiotemporal changes of water quality and eutrophication were assessed by trophic level index (TLI), cluster analysis, and spatial interpolation methods in Lake Taihu and its sub-lakes from 2015 to 2019. Results showed that the Taihu had poor water quality and maintained a light-eutropher state overall, mainly astricted by the total nitrogen (TN) and the total phosphorus (TP). All nutrient parameters reached relatively higher concentrations in the northwestern and northern areas. Meiliang Bay was the most polluted and nutrient-rich area. In terms of trend, the Mann-Kendall test highlighted that the TP and chlorophyll-a (Chl-a) concentrations increased significantly while the TN and five-day biochemical oxygen demand (BOD) decreased. The massive nutrient loads caused by human activity from the northwestern Taihu and the geomorphological characteristic of the north closed bays were the main contributors to the spatial heterogeneity in water quality. The main driving force of the alleviative nitrogen pollution was the declining river inflow nitrogen loading, and phosphorus pollution was affected more by accumulated endogenous pollution and decline in aquatic plants area, as well as closely linked with algae biomass. Further water pollution and eutrophication restoration of Taihu should focus on the nutrient reductions and those heavily polluted closed bays.
水质恶化和城市浅水湖泊富营养化是全球关注的生态问题，需要加大环境努力。本研究采用营养状态指数（TLI）、聚类分析和空间插值方法，评估了 2015 年至 2019 年太湖及其子湖泊的水质和富营养化时空变化。结果表明，太湖水质较差，总体处于轻度富营养状态，主要受总氮（TN）和总磷（TP）的限制。所有营养参数在西北部和北部地区达到相对较高的浓度。梅梁湾是污染最严重和营养最丰富的地区。就趋势而言，Mann-Kendall 检验强调，TP 和叶绿素-a（Chl-a）浓度显著增加，而 TN 和五日生化需氧量（BOD）则下降。西北部太湖的人类活动大量营养负荷和北部封闭湾的地貌特征是水质空间异质性的主要原因。氮污染缓解的主要驱动力是河流流入氮负荷的下降，磷污染受内源污染积累和水生植物面积下降的影响更大，与藻类生物量密切相关。进一步的太湖水污染和富营养化恢复应侧重于减少营养物和那些污染严重的封闭海湾。
