『Abstract
　Annual yields (fluxes per unit area) of Al, Mn, Fe, Ni, Cd, Pb, Zn, Cu, Cr, Co, As and Se were estimated for two small non-tidal stream catchments on the Eastern Shore of the Chesapeake Bay, United States−a poorly drained dissected-upland watershed in the Nanticoke River Basin, and a well-drained feeder tributary in the lower reaches of the Chester River Basin. Both watersheds are dominated by agriculture. A hydrograph-separation technique was used to determine the baseflow and stormflow components of metal yields, thus providing important insights into the effects of hydrology and climate on the transport of metals. Concentrations of suspended-sediment were used as a less-costly proxy of metal concentrations which are generally associated with particles. Results were compared to other studies in Chesapeake Bay and to general trends in metal concentrations across the United States. The study documented a larger than background yield of Zn and Co from the upper Nanticoke River Basin and possibly enriched concentrations of As, Cd and Se from both the upper Nanticoke River and the Chesterville Branch (a tributary of the lower Chester River). The annual yield of total Zn from the Nanticoke River Basin in 1998 was 18,000 g/km²/a, and was two to three times higher than yields reported from comparable river basins in the region. Concentrations of Cd also were high in both basins when compared to crustal concentrations and to other national data, but were within reasonable agreement with other Chesapeake Bay studies. Thus, Cd may be enriched locally either in natural materials or from agriculture.』

『米国チェサピーク湾のEastern Shoreの2つの小さな干満のない河川流域−Nanticoke川盆地の流れの少ない解析された高地流域、およびChester川盆地の下流の流れのよい支流に対して、Al、Mn、Fe、Ni、Cd、Pb、Zn、Cu、Cr、Co、As、およびSeの年間流出量（単位面積当りのフラックス）が見積られた。両方の流域は農業が支配的である。ハイドログラフ分離法が、金属流出量の基底流と豪雨流成分を決定するために使われ、したがってこれは金属の運搬に対する水文と気候の影響についての重要な洞察を与えてくれる。浮遊物質の濃度が、一般に粒子に伴う金属濃度の費用のかからない代用として使われた。結果は、チェサピーク湾の他の研究および、米国中の金属濃度の一般的な傾向と比較された。本研究は、Nanticoke川盆地上流からのZnとCoがバックグラウンド流出量よりも大きいこと、そしてNanticoke川上流とChesterville支流（Chester川下流の支流）の両方からのAs、Cd、Se濃度がおそらく富化されていることを立証した。1998年のNanticoke川盆地からの全Znの年間流出量は18,000 g/km²/年であり、この地域で比較できる河川流域から報告された流出量の2〜3倍大きかった。Cdの濃度もまた、地殻濃度と他の国内データと比べると高かったが、他のチェサピーク湾の研究とはけっこう一致していた。したがって、Cdは天然物ないしは農業から局所的に富化したのであろう。

1. Introduction
　1.1. Background
　1.2. Study areas
2. Materials and methods
　2.1. Sample collection
　2.2. Water-quality measuremants
　2.3. Data evaluation
　2.4. Annual yield calculations
　　2.4.1. Daily dissolved metal flux calculations
　　2.4.2. Daily particulate metal flux calculations
　　2.4.3. Annual yields
3. Metal concentration data − enrichments and partitioning behavior
4. Metal yields
　4.1. Fluxes and yields of aluminum, iron, manganese, and lead
　4.2. Fluxes and yields of copper, nickel, cadmium, and arsenic
　4.3. Fluxes and yields of cobalt and chromium
　4.4. Fluxes and yields of zinc
　4.5. Fluxes and yields of selenium
5. Implications for metal transport in Chesapeake bay
Acknowledgements
Reference