Reaeration Equations Derived from U.S. Geological Survey Database

Melching, Charles S.; Flores, Hala E.

doi:10.1061/(asce)0733-9372(1999)125:5(407)

Cited by 112 publications

(93 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…as a function of water current and depth based on empirical or conceptual approaches, reviewed by Bansal (1973) and more recently by Melching and Flores (1999) and Gualtieri et al (2002). In estuaries, the tidal current can be as high as the gravity flow in streams and, thus, could in theory contribute significantly to k 600 .…”

Section: Contribution Of Water Currents To K 600 -In the Macrotidalmentioning

confidence: 99%

Gas transfer velocities of CO₂ in three European estuaries (Randers Fjord,Scheldt, and Thames)

Borges¹,

Delille²,

Schiettecatte³

et al. 2004

Limnology & Oceanography

268

264

View full text Add to dashboard Cite

We measured the flux of CO 2 across the air-water interface using the floating chamber method in three European estuaries with contrasting physical characteristics (Randers Fjord, Scheldt, and Thames). We computed the gas transfer velocity of CO 2 (k) from the CO 2 flux and concomitant measurements of the air-water gradient of the partial pressure of CO 2 (pCO 2 ). There was a significant linear relationship between k and wind speed for each of the three estuaries. The differences of the y-intercept and the slope between the three sites are related to differences in the contribution of tidal currents to water turbulence at the interface and fetch limitation. The contribution to k from turbulence generated by tidal currents is negligible in microtidal estuaries such as Randers Fjord but is substantial, at low to moderate wind speeds, in macrotidal estuaries such as the Scheldt and the Thames. Our results clearly show that in estuaries a simple parameterization of k as a function of wind speed is site specific and strongly suggest that the y-intercept of the linear relationship is mostly influenced by the contribution of tidal currents, whereas the slope is influenced by fetch limitation. This implies that substantial errors in flux computations are incurred if generic relationships of the gas transfer velocity as a function of wind speed are employed in estuarine environments for the purpose of biogas air-water flux budgets and ecosystem metabolic studies.Based on organic carbon flux budgets, the overall picture of the net ecosystem metabolism in the coastal ocean is that temperate open continental shelves (bordered by a continental margin) are net autotrophic (net exporters of carbon and thus potential sinks for atmospheric CO 2 ) while near-shore 1 Corresponding author (Alberto.Borges@ulg.ac.be). AcknowledgmentsWe thank the crew of the R. V. Belgica for full collaboration during the Scheldt and Thames cruises, Niels Iversen for welcome on the Randers Fjord, Management Unit of the North Sea Mathematical Models for providing thermosalinograph and meteorological data during the Scheldt and Thames cruises, Renzo Biondo, Emile Libert, and Jean-Marie Théate for invaluable technical support, and an anonymous reviewer and J. N. Kremer for constructive comments on a previous version of the paper. This work was funded by the European Union through the BIOGEST (ENV4-CT96-0213) and EUROTROPH (EVK3-CT-2000-00040) projects, and by the Fonds National de la Recherche Scientifique (FRFC 2.4545.02) where A.V.B and M.F. are, respectively, a postdoctoral researcher and a senior research associate. This is MARE contribution 043.

show abstract

Section: Contribution Of Water Currents To K 600 -In the Macrotidalmentioning

confidence: 99%

Gas transfer velocities of CO₂ in three European estuaries (Randers Fjord,Scheldt, and Thames)

Borges¹,

Delille²,

Schiettecatte³

et al. 2004

Limnology & Oceanography

268

264

View full text Add to dashboard Cite

show abstract

“…Thirty distinct empirical equations for the prediction of K 2 were identified from the literature. Application of the equations was supplemented by use of a USGS database containing information from K 2 measurements made using the tracer-gas method at 493 individual sites, some with multiple measurements under varying flow conditions (Melching and Flores 1999). The equations and K 2 database were used with the site-specific measurements of discharge, reachaverage stream velocity, depth, width, and stream slope to estimate K 2 , as follows:…”

Section: Stream Metabolism Calculationsmentioning

confidence: 99%

The relative influence of nutrients and habitat on stream metabolism in agricultural streams

Frankforter

Weyers

Bales

et al. 2009

Environ Monit Assess

View full text Add to dashboard Cite

Stream metabolism was measured in 33 streams across a gradient of nutrient concentrations in four agricultural areas of the USA to determine the relative influence of nutrient concentrations and habitat on primary production (GPP) and respiration reach. When data for all study areas were combined, there were no statistically significant relations between gross primary production or community respiration and any of the independent variables. However, significant regression models were developed for three study areas for GPP (r 2 = 0.79-0.91) and CR-24 (r 2 = 0.76-0.77). Various forms of nutrients (total phosphorus and area-weighted total nitrogen loading) were significant for predicting GPP in two study areas, with habitat variables important in seven significant models. Important physical variables included light availability, precipitation, basin area, and in-stream habitat cover. Both benthic and seston chlorophyll were not found to be important explanatory variables in any of the models; however, benthic ash-free dry weight was important in two models for GPP.

show abstract

“…O elevado valor para K 2 (50%) deve-se à imprecisão das estimativas realizadas pelas equações empíricas (MELCHING & FLORES, 1999;HAIDER et al, 2013).…”

Section: Este Estudo Trata Das Incertezas Associadas Aos Dados De Entunclassified

Análise de incerteza e modelagem de qualidade da água do Rio Uberaba, Minas Gerais

Mateus

Gonçalves

Júnior

et al. 2015

Rev. Bras. Ciênc. Ambient. (Online)

View full text Add to dashboard Cite

RESUMOO objetivo deste estudo foi avaliar o perfil de oxigênio dissolvido (OD) em um trecho urbano da bacia do Rio Uberaba, identificar as principais fontes poluidoras e sugerir medidas de controle. Para tanto, o estudo foi dividido em cinco fases: (i) avaliação da qualidade da água durante um ano hidrológico; (ii) calibração e validação do modelo de qualidade da água; (iii) análise de sensibilidade dos coeficientes e dos dados de entrada do modelo; (iv) análise de incerteza; e (v) criação de cenários para a tomada de decisão. Os resultados mostraram que o Córrego das Lajes é a principal fonte poluidora do Rio Uberaba. O modelo mostrou-se confiável, uma vez que ele pôde ser calibrado e validado. Com a análise de incerteza foi possível mostrar que a probabilidade de o Rio Uberaba atender ao padrão ambiental exigido para a classe 2 (OD≥5,0 mg.L -1 ) é praticamente nula, mas que ela poderia ser elevada para 75,3% se a carga orgânica lançada no rio fosse removida com uma eficiência de 75%.Palavras-chave: modelagem de qualidade da água; análise de incerteza; Rio Uberaba. ABSTRACTThe objective in this study was to evaluate the Dissolved Oxygen (DO) profile along an urban stretch in Uberaba River basin and identify the main pollution sources. For this, the study was divided in five stages: (i) water quality evaluation during a hydrologic year; (ii) calibration and validation of the water quality model; (iii) sensibility analysis of the coefficient and entrance data for the model; (iv) uncertainty analysis; and (v) creation of decision-making scenarios. The results show that Lajes Stream is the main pollution source of Uberaba River. The model demonstrated to be reliable, once it could be calibrated and validated. Through the uncertainty analysis, it is possible to show that the probability of Uberaba River to attempt the environmental standard demanded for class 2 (DO≥5.0 mg.L -1 ) is practically zero, but it could be raised to 75.3% if the organic polluting load released into the river was decreased in 75%.

show abstract

Reaeration Equations Derived from U.S. Geological Survey Database

Cited by 112 publications

References 11 publications

Gas transfer velocities of CO₂ in three European estuaries (Randers Fjord,Scheldt, and Thames)

Gas transfer velocities of CO₂ in three European estuaries (Randers Fjord,Scheldt, and Thames)

The relative influence of nutrients and habitat on stream metabolism in agricultural streams

Análise de incerteza e modelagem de qualidade da água do Rio Uberaba, Minas Gerais

Contact Info

Product

Resources

About

Reaeration Equations Derived from U.S. Geological Survey Database

Cited by 112 publications

References 11 publications

Gas transfer velocities of CO2 in three European estuaries (Randers Fjord,Scheldt, and Thames)

Gas transfer velocities of CO2 in three European estuaries (Randers Fjord,Scheldt, and Thames)

The relative influence of nutrients and habitat on stream metabolism in agricultural streams

Análise de incerteza e modelagem de qualidade da água do Rio Uberaba, Minas Gerais

Contact Info

Product

Resources

About

Gas transfer velocities of CO₂ in three European estuaries (Randers Fjord,Scheldt, and Thames)

Gas transfer velocities of CO₂ in three European estuaries (Randers Fjord,Scheldt, and Thames)