Toward Explaining Nitrogen and Phosphorus Trends in Chesapeake Bay Tributaries, 1992–2012
期刊名称: JAWRA Journal of the American Water Resources Association
作者: Scott W. Ator,Ana Maria García,Gregory E. Schwarz,Joel D.
Blomquist,Andrew J. Sekellick关于珍惜时间的诗
詹姆斯库克大学
溥仪皇后作者机构: Maryland‐Delaware‐DC Water Science Center U.S. Geological Survey Baltimore Maryland USA,South Atlantic Water Science Center U.S. Geological Survey Raleigh North Carolina USA,Water Resources Mission Area U.S.
Geological Survey Reston Virginia USA
年份: 2019年
骊山烽火
期号: 第5期
研究生入党自传>立冬的古诗关键词: nutrients;SPARROW modeling;watershed management, time ries analysis;Chesapeake Bay;stream chemistry
摘要:Understanding trends in stream chemistry is critical to watershed management, and often complicated by multiple contaminant sources and landscape conditions changing over varying time scales. We adapted spatially referenced regression (SPARROW) to infer caus of recent nutrient trends in Chesapeake Bay tributaries by relating obrved fluxes during 1992, 2002, and 2012 to contemporary inputs and watershed conditions. The annual flow-normalized nitrogen flux to the bay from its watershed declined by 14% to 127,000 Mg (metric tons) between 1992 and 2012, due primarily (more than 80% of the decline) to reduced point sources. The remainder of the decline was due to reduced atmospheric deposition (13%) and urban nonpoint sources. Agricultural inputs, which contribute most nitrogen to the bay, changed little, although trends in
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