Filters: Tags: nitrogen (X)1,366 results (122ms)
GIS-based spatial regression and prediction of water quality in river networks: A case study in Iowa
Nonpoint source pollution is the leading cause of the U.S.’s water quality problems. One important component of nonpoint source pollution control is an understanding of what and how watershed-scale conditions influence ambient water quality. This paper investigated the use of spatial regression to evaluate the impacts of watershed characteristics on stream NO3NO2-N concentration in the Cedar River Watershed, Iowa. An Arc Hydro geodatabase was constructed to organize various datasets on the watershed. Spatial regression models were developed to evaluate the impacts of watershed characteristics on stream NO3NO2-N concentration and predict NO3NO2-N concentration at unmonitored locations. Unlike the traditional ordinary...
Baseline data for a hydrological restoration of a mangrove forest near Goodland, Florida (2015 - 2017)
Mangrove restoration has a strong potential to enhance the services provided by coastal wetlands on a number of Department of the Interior (DOI) managed lands throughout the southeastern United States of America. Services include storm protection, water quality improvement, and biological carbon sequestration. Forest structural attributes including basal area, tree height, and stem density by species are used to calculate above ground biomass and above ground productivity. Percent cover is used to asses the forest canopy health. The data collected for the soils are: bulk density, percent total Nitrogen, percent total Carbon, and selected samples percent total Phosporus. The forest structure plots were placed in...
Collection, analysis, and age-dating of sediment cores from salt marshes on the south shore of Cape Cod, Massachusetts, from 2013 through 2014
The accretion history of fringing salt marshes located on the south shore of Cape Cod is reconstructed from sediment cores collected in low and high marsh vegetation zones. These marshes are micro-tidal, with a mean tidal range of 0.442 m. Their location within protected embayments and the absence of large rivers results in minimal sediment supply and a dominance of organic matter contributions to sediment peat. Age models based on 210-lead and 137-cesium are constructed to evaluate how vertical accretion and carbon burial rates have changed over the past century. The continuous rate of supply age model was used to age date 11 cores (10 low marsh and 1 high marsh) across four salt marshes. Both vertical accretion...
This metadata record documents 11 comma delimited tables representing the amount of reported best management practice (BMP) implementation for the years from 1985 to 2014 at three geographic scales: county or land-river modeling segment, River Input Monitoring (RIM) station drainage areas, and the entire Chesapeake Bay Watershed (CBWS). Data originated from the Chesapeake Bay Watershed jurisdictions including Maryland, Pennsylvania, Virginia, Delaware, New York, West Virginia, and the District of Columbia. Data were reported to the Chesapeake Bay Program for an annual review of progress toward meeting nitrogen, phosphorus, and sediment reduction goals.
Data on denitrification and ecological characteristics of nontidal floodplains, Chesapeake Bay watershed, USA, 2013-2016
This data set presents attributes of floodplain ecosystem characteristics including floodplain soil denitrification, floodplain soil biogeochemistry, floodplain vegetation, floodplain sedimentation, floodplain and channel morphometry, stream discharge and water quality, floodplain climate, floodplain physiographic region, and catchment land cover. Attributes are associated with 18 floodplains of the Chesapeake Bay watershed. For many of these attributes, mean values are summaries of multiple measurements made within each floodplain site.
Acetylene fermentation assays, nitrogen fixation assays, and growth studies were performed with Pelobacter sp. strain SFB93 and Pelobacter acetylenicus DSM3246. Data includes concentrations of acetylene and ethylene over time, and growth measured with OD680 and cell counts.
This dataset provides aqueous nitrate+nitrite, aqueous manganese, aqueous iron, and total sulfate measurements in groundwater samples from 254 newly constructed private residential wells between 2014 and 2016. The study focuses on three geologically distinct regions of Minnesota: central, northwest, and northeast. These study regions were chosen due to their prevalent elevated As concentrations in drinking water. Each of the 254 wells were sampled in three rounds by the Minnesota Department of Health (MDH). The timing of the three sampling rounds was (1) immediately or shortly after well construction (round 1); (2) 3-6 months after initial sample collection (round 2); and (3) 12 months after initial sample collection...
Trends in snowpack chemistry and comparison to National Atmospheric Deposition Program results for the Rocky Mountains, US, 1993?2004
Seasonal snowpack chemistry data from the Rocky Mountain region of the US was examined to identify long-term trends in concentration and chemical deposition in snow and in snow-water equivalent. For the period 1993?2004, comparisons of trends were made between 54 Rocky Mountain Snowpack sites and 16 National Atmospheric Deposition Program wetfall sites located nearby in the region. The region was divided into three subregions: Northern, Central, and Southern. A non-parametric correlation method known as the Regional Kendall Test was used. This technique collectively computed the slope, direction, and probability of trend for several sites at once in each of the Northern, Central, and Southern Rockies subregions....
Nitrogen, phosphorus, and suspended-sediment loads, and changes in loads, in rivers across the Chesapeake Bay watershed have been calculated using monitoring data from the nine Chesapeake Bay River Input Monitoring (RIM) stations for the period 1985 through 2015. Nutrient and suspended-sediment loads and changes in loads were determined by applying a weighted regression approach called WRTDS (Weighted Regression on Time, Discharge, and Season). Yields (represents the mass of constituent transported from a unit area of a given watershed) are used to compare the export loads from one basin to another. Yield results are obtained by dividing the annual load (pounds) of a given constituent by the respective watershed...
Estimates of Total Nitrogen and Phosphorus Delivery to Estuaries, Bays, and Sounds Along the U.S. Gulf of Mexico Coast, 2002
This dataset shows the estimated delivered nitrogen load from all sources (livestock manure from confined operations, livestock manure from pasture feeding, livestock manure from feedlots, fertilizer applied to crops, runoff from urban land, combined municipal and wastewater discharge, and from atmospheric deposition)into the estuaries, bays, and sounds along the U.S. Gulf of Mexico coast in 2002.
Relationship between population dynamics of nitrifiers in biofilms and reactor performance at various C:N ratios
Vegetative Regeneration of Panicum racemosum from Rhizome Fragments on Southern Brazilian Coastal Dunes
Effects of land use, climate variation, and N deposition on N cycling and C storage in northern hardwood forests
Atmospheric nitrogen deposition at a conifer forest: response of free amino acids in Engelmann spruce needles
Atmospheric deposition and watershed nitrogen export along an elevational gradient in the Catskill Mountains, New York