A framework to develop joint nutrient criteria for lake eutrophication management in eutrophic lakes
A framework to develop joint nutrient criteria for lake eutrophication management in eutrophic lakes
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DOI：
10.1016/j.jhydrol.2020.125883
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发表时间：
2021-03
影响因子：
6.4
通讯作者：
Zhongyao Liang;Yaoyang Xu;Qianlinglin Qiu;Yong Liu;Wentao Lu;T. Wagner
中科院分区：
文献类型：
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作者：
Zhongyao Liang;Yaoyang Xu;Qianlinglin Qiu;Yong Liu;Wentao Lu;T. Wagner
营养盐标准为湖泊富营养化管理提供了数值依据。然而，有两个障碍阻碍了营养标准的有效应用，包括1)总磷(TP)和总氮(TN)可能共同限制富营养化湖泊中的浮游植物生物量，但它们的标准往往是独立制定的；2)营养标准与基于百分位数的叶绿素遵从性评估方法(CHL；作为浮游植物生物量的衡量标准)之间的联系尚未很好地建立。为了解决这些障碍，我们提出了一个新的营养标准制定的分析框架，在该框架下，使用分位数回归(QR)来制定联合营养标准。我们使用位于中国西南部的富营养化湖泊滇池的TP、TN和CHL数据演示了使用这种新方法所需的步骤。首先，我们建立了六个回归分位数的候选QR模型来量化营养与CHL的关系。接下来，我们进行了序贯Wald检验，为每个回归分位数选择“最佳”模型。最后，我们使用等高线地图可视化了联合营养标准表面。等高线图通过显示TP和TN标准之间的联系，有效地说明了联合养分标准。此外，基于QR，很容易推导出满足百分位数合规性评估要求的营养标准。我们进一步发现，联合营养标准可以帮助选择有效的流域减负策略。提出的方法可以推广到其他系统，并可能有助于特定地点的湖泊富营养化管理。
Nutrient criteria provide the numeric basis for lake eutrophication management. However, there are two obstacles that can hinder the effective application of nutrient criteria, including 1) although total phosphorus (TP) and total nitrogen (TN) might co-limit phytoplankton biomass in eutrophic lakes, their criteria are often developed independently; and 2) the linkage between nutrient criteria and the percentile-based compliance assessment method of chlorophylla(CHL; as a measure of phytoplankton biomass) has not been well established. To resolve these obstacles, we propose a novel analytical framework of nutrient criteria development, by which joint nutrient criteria are developed using quantile regression (QR). We demonstrated the steps necessary to utilize this novel approach using TP, TN, and CHL data from Lake Dianchi, a hypereutrophic lake located in southwestern China. First, we built candidate QR models to quantify the nutrient-CHL relationship at six regression quantiles. Next, we conducted the sequential Wald test to select the “best” model for each regression quantile. Finally, we visualized the joint nutrient criteria surface using a contour map. The contour map effectively illustrated the joint nutrient criteria by showing the linkage of TP and TN criterion. In addition, based on the QR, it was easy to deduce nutrient criteria which met the requirement of percentile-based compliance assessment. We further found that joint nutrient criteria could help the selection of an efficient load reduction strategy in the watershed. The proposed method can be generalized to other systems and may facilitate site-specific lake eutrophication management.