University of Vigo, Agroforestry Group, School of Forestry Engineering, 36005 Pontevedra, Spain.
Center of Chemistry of Vila Real, University of Trás-os-Montes e Alto Douro, Ap. 1013, 5001-801 Vila Real, Portugal.
Sci Total Environ. 2022 Feb 25;809:152155. doi: 10.1016/j.scitotenv.2021.152155. Epub 2021 Dec 7.
Cyano-HABs are proliferating around the world due to anthropogenic nutrient enrichment of freshwater bodies. This study seeks to obtain a holistic vision over the various threats that affect the Cyano-HABs of Umia basin and especially of A Baxe reservoir (Galicia, NW Spain), through the method of Partial least squares path modelling (PLS-PM). The A Baxe reservoirs is a fundamental source of drinking water supply to surrounding dwellings. This study identifies and quantify the variables that increase contaminant concentration and decrease ecological integrity, as well as how this scenario evolved over various hydrologic years. In this regard, the PLS-PM equations will be robust and powerful tools to predict changes in eutrophication and ecological integrity, as response to measures implemented in the basin that can improve water quality. The dependent latent variables are "Eutrophication" (chlorophyl-a, Microcystis sp.) and "Ecological Integrity" (METI Bioindicator). The independent latent variables are "SWP", which represents surface water parameters (phosphorus, nitrogen and pH) and "Climatic Conditions" (temperature, precipitation). The PLS-PM results revealed that 51.0% of "Eutrophication" is predicted by the independent variables. The connections between latent variables are quantified through path coefficients (β). The "SWP" contributes by increasing "Eutrophication" (β = 0.235), the same occurring with the "Climatic Conditions" (β = -0.672). The variables "Eutrophication" (β = -0.217) and "SWP" (β = -0.483) lower the "Ecological Integrity". On the other hand, different trophic scenarios, adapted to the temperature increase predicted for the study area, were tested, and it was found that ecological integrity would improve by 46% if the oligotrophic state were reached. Therefore, it is recommended to prevent pollution by means of water control and governance plans, as well as corrective and preventive measures, which guarantee the water security of the river basins. Despite the complex mathematics behind the PLS-PM models, their user-friendly development and application through interactive graphical interfaces make them easily transposable to other eutrophic reservoirs, widening the readership of these studies focused on multiple-geosphere assessment of environmental impacts.
由于人为的富营养化作用，淡水水体中的蓝藻水华在世界各地不断蔓延。本研究通过偏最小二乘路径模型（PLS-PM）的方法，试图全面了解影响乌米亚流域（西班牙西北部加利西亚），特别是阿拜克水库（A Baxe 水库）的各种威胁。阿拜克水库是周边住宅供水的重要水源。本研究确定并量化了增加污染物浓度和降低生态完整性的变量，以及在不同水文年内该情景的演变过程。在这方面，PLS-PM 方程将是预测富营养化和生态完整性变化的有力工具，这些变化是对流域内可以改善水质的各项措施的响应。因变量是“富营养化”（叶绿素-a、微囊藻属）和“生态完整性”（METI 生物指标）。自变量是“SWP”，代表地表水参数（磷、氮和 pH 值）和“气候条件”（温度、降水）。PLS-PM 结果表明，51.0%的“富营养化”由自变量预测。通过路径系数（β）量化潜变量之间的联系。“SWP”通过增加“富营养化”（β=0.235）对其产生影响，同样的情况也发生在“气候条件”（β=-0.672）上。变量“富营养化”（β=-0.217）和“SWP”（β=-0.483）降低了“生态完整性”。另一方面，测试了适应研究区域预测的温度升高的不同营养水平情景，发现如果达到贫营养状态，生态完整性将提高 46%。因此，建议通过水资源控制和管理计划以及纠正和预防措施来防止污染，从而保障流域的水资源安全。尽管 PLS-PM 模型背后的数学复杂，但通过交互式图形界面友好地开发和应用，使它们可以轻松地应用于其他富营养化水库，扩大了这些侧重于多地球层环境影响评估的研究的读者群体。
