Concentrations of phosphorus (P) and nitrogen (N) in the Great Miami (GM) and Little Miami (LM) basins still remain among the highest detected in the United States. The recent nutrient analysis from the Ohio Environmental Protection Agency revealed slightly above average P and N for the recorded period. To assess the temporal changes of nutrient concentrations, this short communication examined datasets collected in the GM and LM basins for three consecutive years—from 2015 to 2017. Our results indicated abrupt spikes of N concentrations in 2017 for six sample sites. By mapping 3 years of data, we found high annual differences in levels of P in the middle and southeast zones of the watersheds. The concentration levels of N did not change much over 3 years, except for specific hotspots in the middle section of the region. Our results could benefit environmental scientists and watershed managers in identifying optimum conditions and adopting new strategies and tools to further mitigate the input of P and N nutrients into the river systems of the GM and LM basins.

中文翻译：

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2015年至2017年美国俄亥俄州大迈阿密和小迈阿密盆地的磷和氮浓度分析

大迈阿密（GM）和小迈阿密（LM）盆地中的磷（P）和氮（N）浓度仍然是美国检测到的最高浓度之一。来自俄亥俄州环境保护局的最新营养素分析显示，在记录的时期内，磷和氮含量略高于平均水平。为了评估养分浓度的时间变化，这项简短的交流检查了从2015年到2017年连续三年从GM和LM盆地收集的数据集。我们的结果表明，2017年六个采样点的N浓度突然上升。通过绘制3年的数据，我们发现该流域中部和东南部地区的P水平存在很高的年度差异。除了该区域中部地区的特定热点外，N的浓度水平在3年内变化不大。