In 2004, the U.S. Geological Survey (USGS), in cooperation with the NPS, began a 3-year investigation to (1) measure groundwater levels within four local study areas at FIIS, (2) collect groundwater samples from these areas for nutrient (nitrogen) analysis, (3) develop a three-dimensional model of the hydrologic system and adjacent saltwater ...

The average annual streamflow to the Gulf of Mexico, for the period 1981-2005 was 21,700 cubic meters per second. The average annual flux of total nitrogen and total phosphorus was 1,470,000 and 140,000 metric tons …

We have used the historical streamflow and concentration data in regression models to estimate the annual flux of nitrogen (N) to the Gulf of Mexico and to determine where the nitrogen originates within the Mississippi Basin. Results show that for 1980–1996 the mean annual total N flux to the Gulf of Mexico was 1 568 000 t/year.

We calibrated the model using data from a national set of 374 watersheds. Application of the model to the 40 coastal watersheds indicates that atmospheric nitrogen contributions to riverine export range over nearly two orders of magnitude, from 4 to 326 kg km-2 yr-1. The atmosphere is estimated to contribute from 4 to 35 percent of the TN in ...

Understanding benthic fluxes is important for understanding the fate of materials that settle to the Puget Sound, Washington, seafloor, as well as the impact these fluxes have on the chemical composition and biogeochemical cycles of marine waters. Existing approaches used to measure benthic nitrogen flux in Puget Sound and elsewhere were reviewed …

Abstract. Spatially Referenced Regression on Watershed Attributes (SPARROW) was used to provide empirical estimates of the sources, fate, and transport of total nitrogen (TN) and total phosphorus (TP) in the Chesapeake Bay watershed, and the mean annual TN and TP flux to the bay and in each of 80,579 nontidal tributary stream reaches.

Total Nitrogen flux and total phosphorus flux (in metric tons as nitrogen and phosphorus) delivered to the Gulf of Mexico by the Mississippi River Basin during the period 1981 to 2005. The average annual streamflow to …

Here we present 3 years of data on nitrogen (N) losses from one completely forested, one agricultural, and six urban/suburban watersheds, and input-output N budgets for …

The U.S. Geological Survey (USGS), in cooperation with The Nature Conservancy, completed a study to estimate and assess trends in streamflow and annual mean concentrations and flux of nutrients (nitrate plus nitrite, total Kjeldahl nitrogen, and total phosphorus) and total suspended solids at three USGS streamgages (hereafter …

Overview. Fingerprint. Abstract. This chapter reviews information from previous studies regarding nitrogen inputs to landscapes and the associated delivery of nitrogen to …

USGS Modeling Techniques . What is SPARROW? ... The net result at the outlet of the Mississippi River Basin was that mean-annual nitrogen flux in 2002 was less than 5 percent lower in 2002 than modeled mean-annual loads for the 1992 base year, whereas the mean annual phosphorus load was less than 1 percent. ...

Samples were analyzed for nitrate-nitrogen and used to estimate retention and areal uptake rates for multiple subsections within each reach. Although nitrate-nitrogen concentrations did not change significantly after the flood, we found that the spatial variability of within-reach retention and areal uptake increased substantially following the ...

The U.S. Geological Survey (USGS), in cooperation with The Nature Conservancy, completed a study to estimate and assess trends in streamflow and annual mean concentrations and flux of nutrients (nitrate plus nitrite, total Kjeldahl nitrogen, and total phosphorus) and total suspended solids at three USGS streamgages (hereafter referred …

A new USGS sample location at 01193400, Fawn Brook near North Westchester, Connecticut. Hydrologists John Mullaney and Janet Barclay are checking the site for sampling viability. Led by Hydrologic Technician Kaitlin Laabs, the project team is analyzing water samples from 46 small tributaries located in the southern part of the LIS …

We measured oxic fluxes of inorganic nitrogen and phosphorus and dissolved organic carbon (DOC) from sediments in two rivermouths of Green Bay (Lake Michigan, USA). Soluble reactive phosphorus (SRP) flux was positive in most cases (overall mean 1.74 mg SRP m − 2 day − 1 ), as was ammonium (NH 4 ) flux (40.6 mg NH 4 m − …

Statistics and information on the worldwide supply of, demand for, and flow of the mineral commodity nitrogen. Nitrogen (N) is an essential element of life and a part of all plant …

Evapotranspiration and Carbon Flux. Evapotranspiration is the rate of transport of water vapor from the earth's surface into the atmosphere. Evapotranspiration can be computed as reference, potential, or actual evapotranspiration. Reference evapotranspiration is that from a grass surface that is well-watered.

An extensive search of literature was undertaken to summarize known benthic nitrogen fluxes in Puget Sound. A total of 138 individual flux chamber measurements and 38 sets of diffusive fluxes were compiled for this study. Of the diffusive fluxes, 35 new datasets were located, and new flux calculations are presented in this …

Annual and daily concentrations and fluxes of total and dissolved phosphorus, total nitrogen, chloride, and total suspended solids were estimated for 18 monitored tributaries to Lake Champlain by using the Weighted Regressions on Time, Discharge, and Seasons regression model. Estimates were made for 21 or 23 years, depending on data …

The Mississippi and Atchafalaya rivers together contribute ~80% of the freshwater discharge and ~90% of total N export from the United States to the Gulf of Mexico 1.Riverine N flux from the Basin ...

The U.S. Geological Survey collects annual nutrient (nitrogen and phosphorus) and sediment flux data and computes trends that describe the extent to which water-quality conditions are changing within the major Chesapeake Bay tributaries. Two regression-based approaches were compared for estimating annual nutrient and sediment fluxes and for ...

The flux bias statistic, an indicator of the ability of the Weighted Regressions on Time, Discharge, and Season regression models to provide accurate representations of flux, showed acceptable bias (less than ±10 percent) for 68 out of 72 models for total and dissolved phosphorus, total nitrogen, and chloride.

USGS Publications Warehouse. We present estimates of total nitrogen and total phosphorus fluxes in rivers to the North Atlantic Ocean from 14 regions in North …

The most negative nitrate flux (-7.3±0.1 mmole m-2 d-1) was observed within Grizzly Bay (Site 416). Observed nitrate fluxes bracketed the estimated summer fluvial flux of nitrate (3,500 to 5,000 kg-N d-1). …

The USGS Pennsylvania Water Science Center continues to provide scientific information about the water resources of the Susquehanna River Basin, in cooperation with regional and local agencies and stakeholders, and with other USGS Water Science Centers and national programs. ... Flux of Nitrogen, Phosphorous, and Suspended Sediment …

Trends in flow-normalized fluxes at the Susquehanna River at Conowingo, Maryland, streamgage during 1996–2011 indicate a 3.2-percent decrease in total nitrogen, but a 55-percent increase in total phosphorus and a 97 …

Data release includes the U.S. Geological Survey (USGS) estimate of spring nitrogen fluxes from nine tributaries to the Chesapeake Bay from 1985 to 2020. Data are presented from tributaries within the USGS River Input Monitoring (RIM) network identified by site numbers: 01491000, 01578310, 01594440, 01646580, 01668000, 01673000, …

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Nitrogen in the Mississippi Basin--Estimating sources and predicting flux to the Gulf of Mexico: DOI: 10.3133/fs13500: Authors: Donald A. Goolsby, William A. Battaglin: Publication Type: Report: Publication Subtype: USGS Numbered Series: Series Title: Fact Sheet: Series Number: 135-00: Index ID: fs13500: Record Source: USGS Publications ...

Data release includes the U.S. Geological Survey (USGS) estimate of spring nitrogen fluxes summed from nine tributaries to the Chesapeake Bay from 1985 to 2021. Data are presented as the sum from tributaries within the USGS River Input Monitoring (RIM) network identified by site numbers: 01491000, 01578310, 01594440, 01646580, …