SPAtially Referenced Regression On Watershed attributes (SPARROW) models were developed to quantify and improve the understanding of the sources, fate, and transport of nitrogen, phosphorus, and suspended sediment in the northeastern United States. Excessive nutrients and suspended sediment from upland watersheds and tributary …

Many scholars have demonstrated that the presence of nitrogen and phosphorus in sediments is an important part of exploring the biogeochemical cycle of …

Phosphate-containing ocean sediments slowly move to land by the uplifting of areas of the earth's surface. Excess phosphorus and nitrogen in the ecosystem leads to the …

A biological aluminum–based P-inactivation agent (BA-PIA) has been developed and demonstrated to effectively remove nitrogen and phosphorus; however, whether it can control the release of nitrogen and phosphorus in sediment still needs study. This study aimed to examine the effect of BA-PIA on controlling sediment …

To further evaluate the transport of nitrogen, phosphorus, and suspended sediment in the Eucha-Spavinaw drainage area, the U.S. Geological Survey (USGS), in collaboration with the City of Tulsa, estimated the loads and computed temporal trends of these constituents from water-quality and streamflow data collected at five USGS …

The study of the ecological risk assessment of nitrogen and phosphorus in sediments is important to understand the environmental quality of water body in the basin. In this study, taking the ...

The model structure for SFM involves three processes: (1) the sediment receives depositional fluxes of particulate organic carbon and nitrogen, as well as biogenic and inorganic phosphorus and silica, from the overlying water, (2) the decomposition of particulate matter produces soluble intermediates that are quantified as diagenesis …

Consequently, it will be necessary to investigate the total nitrogen (TN) and phosphorus (TP) contents in the sediments, assess the risks of these nutrients to the …

A year-long field investigation was carried out in the most heavily polluted bay of Lake Chaohu to assess the temporal exchanges of ammonium nitrogen and soluble reactive phosphorus (SRP) across the sediment–water interface (SWI) and to provide remediation advises.Results showed that the monthly average fluxes of and SRP were 31.38 and …

Here we show that the average concentrations of nitrogen and phosphorus in lake sediments have increased by 267% and 202%, respectively since 1850. In the model projections, 2030–2100, the nitrogen concentrations in the studied lakes in China may decrease, for example, by 87% in the southern districts and by 19% in the …

Source of sediments and depositional processes of surface sediments along the Prydz Bay were investigated through grain size, organic carbon, nitrogen, phosphorus, calcium carbonate and metal ...

A good correlation between nitrogen and phosphorus in the sediments often indicates a common source or identical production pathway. However, in the present study, such correlations between nitrogen and phosphorus were observed only in the east coast mangrove ecosystems (R 2 = 0.4, p < 0.0001, n = 32). These results indicated …

As the largest and most productive estuary in North America, Chesapeake Bay is a vital ecological and economic resource. In recent decades, however, the bay and its tributaries have been degraded by excessive inputs of nutrients (nitrogen and phosphorus) and sediment from contributing watersheds, and in 1998, the Chesapeake …

Figure ES-1. A nitrogen, phosphorus and sediment TMDL has been developed for each of the 92 Chesapeake Bay segment watersheds. Additionally, President Obama issued Executive Order 13508 on May 12, 2009, which directed the federal government to lead a renewed effort to restore and protect the Chesapeake Bay and its

We used the Soil and Water Assessment Tool (SWAT) with various spatiotemporal data to quantify the contributions of climate and land use changes to runoff, sediment, nitrogen (N) and phosphorus (P) losses in …

This is why nutrient and sediment loads from these nine stations are used to model the total loads to the Chesapeake Bay. Most Recent Data Highlights. The nontidal network mapper is an interactive web page that summarizes the latest findings for nitrogen, phosphorus and suspended-sediment trends. Click the image below to explore the …

Total Kjeldahl nitrogen, total phosphorus and suspended sediment mostly trended downward. Overall, the trends in various forms of nitrogen were observed at most sites irrespective of the degree of development and indicate a change in ecological conditions is affecting the nitrogen cycle throughout the watershed, most likely …

To investigate the restoration effects of native Aegiceras corniculatum mangrove forests, the contents and density of sediment organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) were quantified in an unvegetated mudflat (MF), an area with mature A. corniculatum (AC), and two restored A. corniculatum mangroves …

Here we show that the average concentrations of nitrogen and phosphorus in lake sediments have increased by 267% and 202%, respectively since 1850. In the model projections, 2030–2100, the nitrogen concentrations in the studied lakes in China may decrease, for example, by 87% in the southern districts and by 19% in the northern districts.

High internal sediment loadings increase nitrogen (N) and phosphorus (P) concentrations in the water and thereby accelerate eutrophication and the growth of …

Sediments are important reservoirs of nutrient salts such as nitrogen and phosphorus in lakes, which slow the process of eutrophication by absorbing contaminants in large quantities (Gunnars and Blomqvist 1997).As a consequence, to some extent, sediment is a sink for pollutants (Xing et al. 2021).However, when the environment …

In mangrove ecosystems, strong reciprocal interactions exist between plant and substrate. Under semi-arid climate, Rhizophora spp. are usually predominant, colonizing the seashore, and Avicennia marina develops at the edge of salt-flats, which is the highest zone in the intertidal range. Along this zonation, distribution and speciation of …

is the amount of nutrients or sediment in a river during a period of time (monthly, annually). Trend. is the change in load over multiple years. The goal of the Chesapeake Bay nontidal network is to compute . loads. and . trends. of nitrogen, phosphorus, and sediment in nontidal rivers of the Chesapeake Bay watershed. …

The spatial pattern of sediment nitrogen was determined by wind-induced hydrodynamics. • The spatial pattern of sediment phosphorus was determined by …

Nitrogen and P fertilizer prices increased in this period, especially between 2007 and 2008 (Supplemental Fig. S8). This may have caused farmers to use more manure in place of synthetic fertilizers, potentially contributing to increased NH 4 concentrations. In addition, the number of hogs increased from 2002 to 2011, although we do not have ...

Nitrogen (N) and phosphorus (P), as major nutrients for aquatic ecology, are always important factors for lake eutrophication. It is generally recognized that organic N and P become available to aquatic organisms only after they have been mineralized (Acquaye 1963).Since sediments which were thought to play a key role in releasing of N …

Nitrogen, phosphorus, and suspended-sediment loads, and changes in loads, in major rivers across the Chesapeake Bay watershed have been calculated using monitoring data from the Chesapeake Bay Nontidal Network (NTN) stations stations for the period 1985 through 2020. Nutrient and suspended-sediment loads and changes in …

SPAtially Referenced Regression On Watershed attributes (SPARROW) models were developed to quantify and improve the understanding of the sources, fate, and transport of nitrogen, phosphorus, and suspended sediment in the northeastern United States. Excessive nutrients and suspended sediment from upland watersheds and …

The effects of nitrogen and phosphorus were relatively weak compared to sediment. Several complex and unpredictable 2-way or 3-way interactions among stressors were observed. While sediment addition generally reduced total abundance at high levels, this decrease was amplified by P enrichment at low sediment, whereas the opposite …

Spatially Referenced Regression On Watershed attributes (SPARROW) models were applied to describe and estimate mean-annual streamflow and transport of total nitrogen (TN), total phosphorus (TP), and suspended sediment (SS) in streams and delivered to coastal waters of the southeastern United States on the basis of inputs and management …