A Mass Balance of Nitrogen in a Large Lowland River (Elbe, Germany)

Nitrogen (N) delivered by rivers causes severe eutrophication in many coastal waters, and its turnover and retention are therefore of major interest. We set up a mass balance along a 582 km river section of a large, N-rich lowland river to quantify N retention along this river segment and to identify the underlying processes. Our assessments are based on four Lagrangian sampling campaigns performed between 2011 and 2013. Water quality data served as a basis for calculations of N retention, while chlorophyll-a and zooplankton counts were used to quantify the respective primary and secondary transformations of dissolved inorganic N into biomass. The mass balance revealed an average N retention of 17 mg N m−2 h−1 for both nitrate N (NO3–N) and total N (TN). Stoichiometric estimates of the assimilative N uptake revealed that, although NO3–N retention was associated with high phytoplankton assimilation, only a maximum of 53% of NO3–N retention could be attributed to net algal assimilation. The high TN retention rates in turn were most probably caused by a combination of seston deposition and denitrification. The studied river segment acts as a TN sink by retaining almost 30% of the TN inputs, which shows that large rivers can contribute considerably to N retention during downstream transport.

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Flood Flow Frequency Analysis to Estimate Potential Floodplain Nitrogen Treatment during Overbank Flow Events in Urban Stream Restoration Projects

Water ◽

10.3390/w12061568 ◽

2020 ◽

Vol 12 (6) ◽

pp. 1568

Author(s):

Barbara A. Doll ◽

J. Jack Kurki-Fox ◽

Jonathan L. Page ◽

Natalie G. Nelson ◽

Jeffrey P. Johnson

Keyword(s):

North Carolina ◽

Chesapeake Bay ◽

Stream Restoration ◽

Nitrogen Retention ◽

Quality Data ◽

Urban Stream ◽

Water Quality Data ◽

Total N ◽

North Carolina Department ◽

Overbank Flow

Stream restoration for mitigation purposes has grown rapidly since the 1980s. As the science advances, some organizations (Chesapeake Bay Program, North Carolina Department of Environmental Quality) have approved or are considering providing nutrient credits for stream restoration projects. Nutrient treatment on floodplains during overbank events is one of the least understood processes that have been considered as part of the Chesapeake Bay Program’s Stream Restoration Nutrient Crediting program. This study analyzed ten years of streamflow and water quality data from five stations in the Piedmont of North Carolina to evaluate proposed procedures for estimating nitrogen removal on the floodplain during overbank flow events. The volume of floodplain flow, the volume of floodplain flow potentially treated, and the nitrogen load retained on the floodplain were calculated for each overbank event, and a sensitivity analysis was completed. On average, 9% to 15% of the total annual streamflow volume accessed the floodplain. The percentage of the average annual volume of streamflow potentially treated ranged from 1.0% to 5.1%. Annually, this equates to 0.2% to 1.0% of the total N load retained/removed on the floodplain following restoration. The relatively low nitrogen retention/removal rates were due to a majority of floodplain flow occurring during a few large events each year that exceeded the treatment capacity of the floodplain. On an annual basis, 90% of total floodplain flow occurred during half of all overbank events and 50% of total floodplain flow occurred during two to three events each year. Findings suggest that evaluating only overbank events may lead to undervaluing stream restoration because treatment is limited by hydrologic controls that restrict floodplain retention time. Treatment is further governed by floodplain and channel size.

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Data visualization, time-series analysis, and mass-balance modeling of hydrologic and water-quality data for the McTier Creek watershed, South Carolina, 2007-2009

Open-File Report ◽

10.3133/ofr20111209 ◽

2012 ◽

pp. i-21

Author(s):

Stephen T. Benedict ◽

Paul Conrads ◽

Toby D. Feaster ◽

Celeste A. Journey ◽

Heather E. Golden ◽

...

Keyword(s):

Water Quality ◽

Time Series ◽

South Carolina ◽

Time Series Analysis ◽

Mass Balance ◽

Data Visualization ◽

Quality Data ◽

Water Quality Data ◽

Series Analysis ◽

Creek Watershed

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Reduced tillage: Influence on erosion and nutrient losses in a clayey field in southern

Agricultural and Food Science ◽

10.23986/afsci.5711 ◽

2002 ◽

Vol 11 (1) ◽

pp. 37-50 ◽

Cited By ~ 10

Author(s):

J. KOSKIAHO ◽

S. KIVISAARI ◽

S. VERMEULEN

Keyword(s):

Surface Runoff ◽

Quality Data ◽

Reduced Tillage ◽

Nutrient Losses ◽

N Loss ◽

Drainage Flow ◽

N Losses ◽

Water Quality Data ◽

Total N ◽

Total P

Reduced tillage was compared with traditional ploughing in terms of erosion and phosphorus (P) and nitrogen (N) losses in an experimental field in southern Finland. One part of the field has been ploughed (treatment PF) and the other part harrowed (treatment NPF) every autumn since 1986. Flow volume and water quality data was collected separately from surface runoff and subsurface drainage waters during 1991-1995 (surface runoff volume since 1993). Erosion was higher in PF (on average 234 kg ha-1yr-1 in drainage flow and 479 kg ha-1 yr-1 in surface runoff) than in NPF (158 kg ha-1yr-1 in drainage flow and 160 kg ha-1yr-1 in surface runoff). Total N loss in drainage flow was also higher in PF (7.2 kg ha-1yr-1) than in NPF (4.6 kg ha-1yr-1). Total P losses did not differ much

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Surface Water Quality Assessment of Wular Lake, A Ramsar Site in Kashmir Himalaya, Using Discriminant Analysis and WQI

Journal of Ecosystems ◽

10.1155/2014/724728 ◽

2014 ◽

Vol 2014 ◽

pp. 1-18 ◽

Cited By ~ 22

Author(s):

Salim Aijaz Bhat ◽

Ashok K. Pandit

Keyword(s):

Water Quality ◽

Discriminant Analysis ◽

Quality Data ◽

Stepwise Discriminant Analysis ◽

Multivariate Techniques ◽

Kashmir Himalaya ◽

Water Quality Data ◽

Data Set ◽

Total N ◽

The Mean

Multivariate techniques, discriminant analysis, and WQI were applied to analyze a water quality data set including 27 parameters at 5 sites of the Lake Wular in Kashmir Himalaya from 2011 to 2013 to investigate spatiotemporal variations and identify potential pollution sources. Spatial and temporal variations in water quality parameters were evaluated through stepwise discriminant analysis (DA). The first spatial discriminant function (DF) accounted for 76.5% of the total spatial variance, and the second DF accounted for 19.1%. The mean values of water temperature, EC, total-N, K, and silicate showed a strong contribution to discriminate the five sampling sites. The mean concentration of NO2-N, total-N, and sulphate showed a strong contribution to discriminate the four sampling seasons and accounted for most of the expected seasonal variations. The order of major cations and anions was Ca2+>Mg2+> Na+>K+ and Cl->SO42->SiO22- respectively. The results of water quality index, employing thirteen core parameters vital for drinking water purposes, showed values of 49.2, 46.5, 47.3, 40.6, and 37.1 for sites I, II, III, IV, and V, respectively. These index values reflect that the water of lake is in good condition for different purposes but increased values alarm us about future repercussions.

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Impact of Water Quality Detorioration in Mangrove Forest in Semarang Coastal Area

Indonesian Journal of Limnology ◽

10.51264/inajl.v2i2.20 ◽

2021 ◽

Vol 2 (2) ◽

pp. 37-48

Author(s):

Kenanga Sari ◽

Tri Retnaningsih Soeprobowati

Keyword(s):

Water Quality ◽

Coastal Area ◽

Environmental Changes ◽

Principal Component ◽

Quality Standard ◽

Quality Data ◽

Physical Parameters ◽

Water Quality Data ◽

Total N ◽

The North

The fast-growing development and industrialization have caused various impacts on nature including heavy metal pollution, especially in the coastal area. Tambakredjo, located in the North Semarang city, is home to a large number of mangrove and animal species. Therefore, water quality is important. This study was conducted to analyze water quality in the coastal area of Tambakredjo based on physical and chemical measurements. Water quality data were collected from different sites. Physical parameters (temperature, pH, DO, EC, TDS, ORP and salinity) and chemical parameters (Total N, Total P, Pb, Cr, Cd) were observed. Multivariate statistical techniques, including Principal Component Analysis (PCA), was applied to evaluate water quality. The results showed first principal component is 76.27%, where the highest conductivity, total dissolved solids and salinity are associated with site 1. Content of Lead 1.289 ppm, Cadmium 0.021 ppm, and Chromium 0.352 ppm exceeds the water quality standard PP. No. 82/2001. It indicated that Site 1 was characterized as the most heavily polluted site because the location received pollutants from rivers and oceans. This study also examined the short-term changes of the mangrove-covered area at the side of Banjir Kanal Timur using historical map satellite images. The results show that mangrove coverage in Tambakredjo near the aquaculture area had decreased from 1,875m2 to 1,401m2. Meanwhile, on the other site, the mangrove planting effort as a restoration program is carried out, especially in the estuary of Banjir Kanal Timur to anticipate more environmental changes.

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