摘要
为弄清长江中下游浅水湖泊水体氮磷比(TN/TP)对湖泊富营养化状况及水系连通性的指示意义,对该区域26个湖泊开展了春、夏两季的水质调查,比较了不同水文、水质状况湖泊之间TN/TP差异,探讨了影响湖泊TN/TP的主要因素.结果发现,长江中下游湖泊TN/TP存在较大的时空差异性,春季TN/TP平均值为21.52±14.28,过水性湖泊、深水湖泊以及富营养化湖泊3种类型水体中,富营养化湖泊的TN/TP较低,为14.38±7.40,深水湖泊的TN/TP最高,为40.97±33.37;夏季调查湖库的TN/TP平均值为21.73±23.78,其中深水湖泊的TN/TP仍为最高,达96.38±45.91,富营养化湖泊的TN/TP仍为最低,达10.91±4.44.春、夏相比,过水性湖泊和深水湖泊夏季的TN/TP显著上升,而富营养化湖泊却明显下降,且降幅随富营养化程度升高而加大.相关性分析发现,无论是春季还是夏季,湖泊TN/TP都与水体深度显著正相关.此外,湖泊富营养化程度越高,TN/TP与浮游植物生物量的关系就越弱,富营养化程度越低,TN/TP越高,磷对浮游植物生长的限制越明显.研究表明,长江中下游湖泊富营养化治理营养盐策略上,多数湖泊控磷更为重要,在一些富营养化较为严重的湖泊,局部疏浚、合理挖深、外源控制和调整渔业生产方式等是值得探索的修复途径.
In spring and summer of 2018,26 lakes in the middle and lower reaches of the Yangtze River were studied to determine the temporal and spatial characteristics of nitrogen and phosphorus ratios(TN/TP)and their influencing factors.The differences in nitrogen and phosphorus ratios in different types of lakes(including water-psaaing lakes,deep reservoirs and eutrophic lakes)and in different seasons were analyzed in terms of the sources of the lakes,lake depth,suspended particulate matter concentrations,and phytoplankton levels.The average TN/TP was 21.52±14.28 in spring and 21.73±23.78 in summer.The TN/TP varied significantly in different types of lakes.The TN/TP ratios in water-passing lakes,deep reservoirs and eutrophic lakes were 20.41±9.25,40.97±33.37,and 14.38±7.40 during spring,and were 22.62±6.48,96.38±45.91,and 10.91±4.44 during summer,respectively.The TN/TP of the water-passing lakes and deep reservoirs increased significantly in summer,while that of the eutrophic lakes decreased significantly,which indicates that TN/TP changes and lake nutritional status are closely related.The source of nutrients in lakes and reservoirs affects the TN/TP.The TN/TP of lakes and reservoirs had a significant correlation with the lake depth in both spring and summer,indicating that lake depth is a key factor affecting the ratio of nitrogen and phosphorus.In addition,in eutrophic lakes with higher absolute nutrient concentrations,TN/TP has less effect on phytoplankton,while in deep-water lakes with lower absolute nutrient concentrations,TN/TP can determine the growth of phytoplankton limited by phosphorus.Therefore,the governance strategy of lakes in the middle and lower reaches of the Yangtze River should prioritize phosphorus control.Local digging,controlling non-point source pollution,sediment dredging,and changing fishery production methods can be applied to improve the ecological quality of the eutrophic lakes.
作者
季鹏飞
许海
詹旭
朱广伟
邹伟
朱梦圆
康丽娟
JI Peng-fei;XU Hai;ZHAN Xu;ZHU Guang-wei;ZOU Wei;ZHU Meng-yuan;KANG Li-juan(School of Environment and Civil Engineerimg,Jiangnan University,Wuxi 214122,Chima;Taihu L.aboratory for Lake EcosystemReseareh,State Key Laboratory of Lake Secience and Environment,Nanjing Institute of CGeography and Limnology,Chinese Academy ofSciences,Nanjing 210008,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2020年第9期4030-4041,共12页
Environmental Science
基金
国家自然科学基金项目(41573076,41671494)
国家水体污染控制与治理科技重大专项(2017ZX07203-001)
中国科学院前沿科学重点研究项目(QYZDJ-SSW-DQC008)。
关键词
长江中下游
氮磷比
富营养化
水深
浮游植物
middle and lower reaches of Yangtze River
nitrogen-phosphorus ratio
eutrophication
water depth
phytoplankton