Summer Driving Factors and Their Quantitative Contribution to Algae Bloom Occurrence and Demise in the Middle and Lower Hanjiang River in 2022
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摘要: 为探究2022年夏季长江流域“汛期反枯”极端水文条件下汉江中下游首次出现的蓝藻水华成因,选取叶绿素浓度为水华表征指标,考虑各环境因子间的多重共线性关系,采用偏最小二乘回归(PLSR)量化了不同环境因子对汉江中下游仙桃、宗关断面蓝藻水华生消的贡献率。结果表明:(1)仙桃断面叶绿素a浓度与水温、pH、溶解氧和总磷均呈显著正相关关系,与氮磷比呈显著负相关关系;宗关断面叶绿素a浓度与水温、pH、溶解氧均呈显著正相关关系,与日均水位、水位日变幅、流量、总磷和氨氮均呈显著负相关关系;(2)溶解氧、pH和水温对水华生消的贡献程度较高,对仙桃断面的贡献率分别为15.18%、13.68%和14.50%,对宗关断面的贡献率分别为18.06%、15.93%和15.65%;(3)基于偏最小二乘路径模型(PLS-PM)的环境因子解析显示,气象因子是2022年夏季汉江中下游蓝藻水华暴发的诱导因子,水华“萌发”时段可能与汉江中下游涝旱急转时段重叠。建议后续研究结合准确的中长期气象预报信息,在涝旱急转时段优化汉江中下游水华防控调度的下泄流量与下泄时机,提高水华防控效果。Abstract: Under the extreme hydrological conditions of high temperature and drought in the Yangtze River basin in the summer of 2022, cyanobacteria blooms occurred for the first time in the middle and lower reaches of Hanjiang River. In this study, we identified the driving factors of algae blooms and quantified the contribution of each driving factor in the Xiantao and Zongguan sections in the Hanjiang River, aiming to provide scientific evidence and decision support for the prevention and control of algae blooms. The concentration of chlorophyll-a was selected as the indicator of algae blooms in this study, and partial least squares regression(PLSR) was used due to the multicollinearity relationship between environmental factors.Resultsshow that:(1) The concentration of chlorophyll-a in the Xiantao section presented a significantly positive correlation with water temperature, pH, dissolved oxygen(DO) and total phosphorus(TP), and a significantly negative correlation with the ratio of nitrogen to phosphorus. The concentration of chlorophyll-a in the Zongguan section presented a significantly positive correlation with water temperature, p H and the DO, and a significantly negative correlation with the daily average water level, daily water level fluctuation, flow, TP and ammonia nitrogen.(2) The DO, pH and water temperature contributed most to the occurrence and demise of algae blooms, with respective contribution rates of 15.18%, 13.68%, 14.50% in the Xiantao section, and 18.06%, 15.93%,15.65% in the Zongguan section.(3) The impact paths of various environmental factors on changes in chlorophyll-a concentration were analyzed based on Partial Least Squares Path Modeling(PLS-PM),and the results indicate that meteorological factors induced the outbreak of cyanobacteria blooms in the middle and lower reaches of the Hanjiang River in summer of 2022, and that the formation(germination) period of summer algae blooms may overlap with "abrupt flood-drought transition" periods.Therefore, to effectively prevent and control algae blooms in the middle and lower reaches of Hanjiang River, we recommend regulating the discharge and time of water flow in combination with accurate medium and long term weather forecast information during "abrupt flood and drought transition" periods. This study has the potential to significantly enhance the efficiency and effectiveness of algae bloom prevention and control.
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偏最小二乘回归方法及其应用[M].北京:国防工业出版社.
Anggara Kasih G A,Kitada T,2004.Numerical simulation of water quality response to nutrient loading and sediment re⁃suspension in Mikawa Bay,central Japan:quantitative eval⁃uation of the effects of nutrient-reduction measures on al⁃gal blooms[J].Hydrological Processes,18(16):3037-3059.
Bowes M,Gozzard E,Johnson A,et al,2012.Spatial and tem⁃poral changes in chlorophyll-a concentrations in the Riv⁃er Thames basin,UK:are phosphorus concentrations be⁃ginning to limit phytoplankton biomass?[J].Science of the Total Environment,426:45-55.
Chislock M F,Sharp K L,Wilson A E,2014.Cylindrospermop⁃sis raciborskii dominates under very low and high nitro⁃gen-to-phosphorus ratios[J].Water Research,49:207-214.
Filardo M J,Dunstan W N,2011.Hydrodynamic control of phytoplankton in low salinity waters of the James River Estuary,USA[J].Estuary,Coast and Shelf Science,21:653-667.
Hilton J,O'Hare M,Bowes M J,et al,2006.How green is my river?A new paradigm of eutrophication in rivers[J].Sci⁃ence of the Total Environment,365(1):66-83.
Huisman J,Codd G A,Paerl H W,et al,2018.Cyanobacterial blooms[J].Nature Reviews Microbiology,16(8):471-483.
Jon O,Gary C,2000.Major chemistry of sediments from the Darling River and its tributaries:implications for sedi⁃ment and phosphorus sources[J].Hydrological Processes,14(7):1-17.
Klaus J,Wetzel C E,Martínez-Carreras N,et al,2015.A trac⁃er to bridge the scales:on the value of diatoms for tracing fast flow path connectivity from headwaters to mesoscale catchments[J].Hydrological Processes,29(25):5275-5289.
Mhamdi B A,Azzouzi A,Mhamdi M A,et al,2007.Dynamics of the relative nitrogen and phosphorus concentrations in a reservoir situated in a semi-arid zone (Sahela,Morocco)[J].Water Resources Management,21:983-995.
Mosley L M,Zammit B,Leyden E,et al,2012.The Impact of Extreme Low Flows on the Water Quality of the Lower Murray River and Lakes (South Australia)[J].Water Re⁃sources Management,26:3923-3946.
Sellers T,Bukaveckas P A,2003.Phytoplankton production in a large,regulated river:A modeling and mass balance as⁃sessment[J].Limnology and Oceanography,48(4):1476-1487.
Wold S,Sjostrom M,Eriksson L,2001.PLS-regression:A ba⁃sic tool of chemometrics[J].Chemometrics and Intelligent Laboratory Systems,58(2):109-130.
Xin X K,Zhang H,Lei P,et al,2020.Algal blooms in the mid⁃dle and lower Han River:Characteristics,early warning and prevention[J].Science of the Total Environment,706:135293.
Yan H,Wang G,Wu D,et al,2017.Water Bloom Precursor Analysis Based on Two Direction S-Rough Set[J].Water Resources Management,31:1435-1456.
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