scholarly journals Traveltime, reaeration, and water-quality characteristics during low-flow conditions in Wilsons Creek and the James River near Springfield, Missouri

1987 ◽  
Keyword(s):  
Water Quality ◽  
Quality Characteristics ◽  
Low Flow ◽  
Flow Conditions ◽  
James River

River flow abstraction due to hydraulic storage at freezeup

2009 ◽  
Vol 36 (3) ◽  
pp. 519-523 ◽  
Author(s):  
Spyros Beltaos
Keyword(s):  
Water Quality ◽  
River Flow ◽  
Ice Cover ◽  
Low Flow ◽  
Flow Data ◽  
Flow Conditions ◽  
Ice Concentration ◽  
Cover Thickness ◽  
Water Quality And Quantity

A hydrologic extreme that can be partly generated by ice effects is low winter flow, which is known for potential impacts on water quality and quantity of rivers receiving effluent discharges or industrial withdrawals. Flow abstraction caused by hydraulic storage during the upstream propagation of an ice cover is quantified using the equations of continuity for ice and water. The flow abstraction is shown to increase with increasing ice concentration, but to decrease with increasing ice cover thickness. Numerical values are consistent with winter abstractions indicated by flow data from Canadian hydrometric stations. The present results further suggest that low-flow conditions in winter should generally improve, or at least not deteriorate, under a warmer climate.

scholarly journals Water Quality Characteristics Evaluation by Flow Conditions Using Load Duration Curve - in Youngbon A Watershed -

2013 ◽  
Vol 22 (4) ◽  
pp. 319-327 ◽  
Author(s):  
Jinhwan Park ◽  
Kapsoon Kim ◽  
Jaewoon Jung ◽  
Kyungsup Hwang ◽  
Myungjin Moon ◽  
...  
Keyword(s):  
Water Quality ◽  
Quality Characteristics ◽  
Flow Conditions ◽  
Load Duration ◽  
Load Duration Curve

Sources and Persistence of Fecal Coliform Bacteria in a Rural Watershed

2003 ◽  
Vol 38 (1) ◽  
pp. 33-47 ◽  
Author(s):  
Rob C. Jamieson ◽  
Robert J. Gordon ◽  
Steven C. Tattrie ◽  
Glenn W. Stratton
Keyword(s):  
Water Quality ◽  
Fecal Coliform ◽  
Monitoring Program ◽  
Stream Sediments ◽  
Low Flow ◽  
Coliform Bacteria ◽  
Recreational Water ◽  
Flow Conditions ◽  
Small Catchment ◽  
Recreational Water Quality

Abstract Water quality within the Thomas Brook watershed, which is a small catchment located in the headwaters of the Cornwallis River drainage basin, was assessed through an integrated monitoring program. The Thomas Brook watershed is approximately 1000 ha and is characterized by both agricultural and residential land uses. Fecal coliform concentrations and stream flow were monitored at several points throughout the watershed during an eight-month period (May to December, 2001). Thomas Brook was seriously degraded with respect to microbial water quality. Fecal coliform levels frequently exceeded recreational water quality guidelines. At the watershed outlet, 94% of the collected samples exceeded the recreational water quality guideline during low flow conditions. Substantial bacterial loading was observed along stream reaches impacted by livestock operations. Bacterial loading was also observed along a stream reach that was not impacted by agricultural activities. A dense clustering of residences, using on-site septic systems, was the suspected source. Results from this study indicate the presence of a reservoir of fecal microorganisms within the stream sediments. The release of fecal microorganisms from the stream sediments to the water column during both low and high flow conditions could be a major source of bacterial loading.

Estimating river water-quality trends under different flow conditions

2021 ◽  
Author(s):  
Qian Zhang ◽  
James Webber ◽  
Douglas Moyer ◽  
Jeffrey Chanat
Keyword(s):  
Water Quality ◽  
River Water ◽  
Total Nitrogen ◽  
Nitrogen Concentration ◽  
High Flow ◽  
River Water Quality ◽  
Low Flow ◽  
Flow Conditions ◽  
Particulate Nitrogen ◽  
Water Quality Trends

<p>A number of statistical approaches have been developed to quantify the overall trend in river water quality, but most approaches are not intended for reporting separate trends for different flow conditions. We propose an approach called FN<sub>2Q</sub>, which is an extension of the flow-normalization (FN) procedure of the well-established WRTDS (“Weighted Regressions on Time, Discharge, and Season”) method. The FN<sub>2Q</sub> approach provides a daily time series of low-flow and high-flow FN flux estimates that represent the lower and upper half of daily riverflow observations that occurred on each calendar day across the period of record. These daily estimates can be summarized into any time period of interest (e.g., monthly, seasonal, or annual) for quantifying trends. The proposed approach is illustrated with an application to a record of total nitrogen concentration (632 samples) collected between 1985 and 2018 from the South Fork Shenandoah River at Front Royal, Virginia (USA). Results show that the overall FN flux of total nitrogen has declined in the period of 1985–2018, which is mainly attributable to FN flux decline in the low-flow class. Furthermore, the decline in the low-flow class was highly correlated with wastewater effluent loads, indicating that the upgrades of treatment technology at wastewater treatment facilities have likely led to water-quality improvement under low-flow conditions. The high-flow FN flux showed a spike around 2007, which was likely caused by increased delivery of particulate nitrogen associated with sediment transport. The case study demonstrates the utility of the FN<sub>2Q</sub> approach toward not only characterizing the changes in river water quality but also guiding the direction of additional analysis for capturing the underlying drivers. The FN<sub>2Q</sub> approach (and the published code) can easily be applied to widely available river monitoring records to quantify water-quality trends under different flow conditions to enhance understanding of river water-quality dynamics. <span>(Journal article: https://doi.org/10.1016/j.scitotenv.2020.143562; R code and data release: https://doi.org/10.5066/P9LBJEY1).</span></p>

Calibration of QUAL2E Model for the Sava River (Slovenia)

1999 ◽  
Vol 40 (10) ◽  
pp. 111-118 ◽  
Author(s):  
A. Drolc ◽  
J. Zagorc Končan
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Rate Constant ◽  
The United States ◽  
Low Flow ◽  
Flow Conditions ◽  
Sava River ◽  
The Impact ◽  
The Sava River ◽  
Oxygen Concentrations

The use of mathematical models is a good decision making tool in river basin management for selection of wastewater treatment technologies and for estimation of the impact of discharged wastewater on the quality of receiving streams. In rivers mostly polluted with degradable organic matter, the major effect of wastewater discharge results in a substantial decrease of dissolved oxygen. The model QUAL2E developed by the United States Environmental Protection Agency was applied to wastewater impact assessment in the Sava river (Slovenia). We present the procedures for the determination of input data for the QUAL2E model. The sediment oxygen demand rate constant was determined experimentally in situ using an specially designed device; the degradation rate constant was determined in a river laboratory model; hydrological characteristics were evaluated on the basis of empirical coefficients; while the reaeration rate constant was calculated on the basis of an energy dissipation model. The mathematical water quality model QUAL2E was calibrated on the basis of field and laboratory measurements and validated with an independent set of data for critical summer low flow conditions when the dissolved oxygen concentrations are low. A sensitivity analysis of the model was also performed. The validated model was then used to estimate the impact of municipal and industrial wastewater discharges on dissolved oxygen concentrations in the Sava river near Ljubljana. The model was used to simulate various conditions in the river and various degrees of treatment of discharged wastewaters. It is estimated according to the model predictions that at critical summer low flow conditions, wastewater should be treated to reach a BOD under 30 mg l−1 with the goal that Slovenian water quality standards are not violated, meaning a dissolved oxygen concentration above 5 mg l−1.

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