Annual nutrient loading and yield to Plum Island Estuary, as measured at the Ipswich and Parker Dams

Nutrient concentrations for various forms of N, P, C, as well as suspended sediments, are determined from monthly grab samples taken at the Ipswich and Parker dams. These nutrient concentrations are then used in conjunction with USGS discharge data (recorded at gages in the Parker River at Byfield, MA and the Ipswich River at Ipswich, MA) to calculate annual nutrient loading to the Estuary, coming over each dam. Annual yield is also calculated for both dams.

针对氮（N）、磷（P）、碳（C）等多种形态的营养盐浓度以及悬浮沉积物浓度，均通过在伊普斯维奇大坝（Ipswich Dam）与帕克大坝（Parker Dam）采集的月度瞬时水样（grab sample）测定获得。随后将上述营养盐浓度数据与美国地质调查局（USGS）的径流数据（该数据由位于马萨诸塞州拜菲尔德的帕克河及马萨诸塞州伊普斯维奇的伊普斯维奇河的水文监测站点记录）结合使用，以计算经由各大坝输入至该河口的年度营养盐负荷。同时还针对两座大坝分别计算了年度营养盐产出量。