Spatial and Temporal Variations in Phosphorus Loads in the Illinois River Basin, Illinois USA
Spatial and Temporal Variations in Phosphorus Loads in the Illinois River Basin, Illinois USA
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美国伊利诺伊州伊利诺伊河流域磷负荷的时空变化
DOI：
10.1111/1752-1688.13054
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Kim, Daniel Chulgi
中科院分区：
文献类型：
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作者：
McIsaac, Gregory F.;Hodson, Timothy O.;Markus, Momcilo;Bhattarai, Rabin;Kim, Daniel Chulgi
美国中北部许多河流的总磷（TP）负荷都有所增加，包括美国伊利诺伊州山谷城的伊利诺伊河，尽管努力减少点源和非点源的负荷，但从1989-1996年到2015-2019年，该河流的总磷负荷增加了39%。在这里，我们量化了伊利诺伊河及其支流中磷（P）负荷的长期变化，并确定了可能导致变化的因素。我们计算了河流负荷的溶解（DP）和颗粒P（PP），总悬浮固体和挥发性悬浮固体（TSS和VSS），以及其他潜在的相关成分在41个地点。从1989-1996年到2015-2019年，DP负荷普遍增加，PP和TSS负荷普遍下降。在1989-1996年期间，P积累在较低的盆地之间的马赛和谷城（不包括监测的支流）。盆地的这一部分非常平坦，沉积物积聚。在2015-2019年期间，该部分从净汇转变为P的净源，占Valley City TP负荷增加的78%。我们目前的证据支持几种机制，可能会导致这种转变：增加DP和氯化物负荷，减少硫酸盐和硝酸盐浓度影响离子强度和氧化还原电位的沉积物，并增加VSS负荷在山谷城市可能表明更大的藻类生产和缺氧在较低的河流沉积物。需要进一步的研究来量化这些机制的相对重要性。
Total phosphorus (TP) loads in many rivers in the north‐central United States have increased, including the Illinois River at Valley City, Illinois, USA, which increased 39% from the periods 1989–1996 to 2015–2019 despite efforts to reduce loads from point and nonpoint sources. Here, we quantify long‐term variations in phosphorus (P) loads in the Illinois River and its tributaries and identify factors that may be causing the variations. We calculated river loads of dissolved (DP) and particulate P (PP), total and volatile suspended solids (TSS and VSS), and other potentially related constituents at 41 locations. DP loads generally increased and PP and TSS loads generally decreased from 1989–1996 to 2015–2019. During 1989–1996, P accumulated in the lower basin between Marseilles and Valley City (excluding monitored tributaries). This portion of the basin is very flat and accumulates sediment. During 2015–2019, this section shifted from being a net sink to being a net source of P, accounting for 78% of the increased TP load at Valley City. We present evidence supporting several mechanisms that could have caused this shift: increased DP and chloride loads, reduced sulfate and nitrate concentrations influencing ionic strength and redox potential in the sediments, and increased VSS loads at Valley City possibly indicating greater algal production and contributing to hypoxia in lower river sediments. Additional research is needed to quantify the relative importance of these mechanisms.