Geochemistry of Cu, Zn and Fe in the Tambo River, Australia II. Field investigation under low-flow conditions

2008 ◽  
Vol 59 (1) ◽  
pp. 80 ◽  
Author(s):  
Barry T. Hart ◽  
Tina Hines ◽  
Bruce A.W. Coller
Keyword(s):  
River Flow ◽  
Field Investigation ◽  
Low Flow ◽  
Flow Conditions ◽  
Study Region ◽  
Hydrous Iron Oxide ◽  
Input Region ◽  
Flow Filtration ◽  
Colloidal Fraction ◽  
Cu And Zn

The behaviour of Fe, Cu and Zn, added to the upper Tambo River (Victoria, Australia) via a metal-enriched groundwater input, was studied during a period of very low river flow. Water samples were collected over a 1.3-km section of the river located immediately downstream of the spring input. Heavy metals were separated into three fractions (dissolved, colloidal and particulate) using tangential flow filtration. Within the ‘input region’, the pH was low (5.1–5.8) and sulphate (306–359 mg L–1), total Fe (2.81 mg L–1), total Cu (19.7 mg L–1) and total Zn (24.1 mg L–1) concentrations all increased significantly. Subsequently, the total metal concentrations reduced with distance downstream of the input, and approached values similar to those recorded upstream of the input region at the end of the study region. Most of the Fe was oxidised before it entered the river as a thick hydrous iron oxide floc that travelled downstream close to the riverbed. The remaining dissolved Fe (mainly Fe(II)) that entered the river largely controlled the behaviour of Cu and Zn in the ‘active region’ (75–400 m). This Fe(II) was rapidly oxidised to Fe(III), which then removed large amounts of the dissolved Cu (65%) and Zn (55%) into the colloidal fraction. Processes such as settling of particles, dilution by groundwater inputs and sorption of dissolved Cu and Zn onto sediments removed the remainder of the Cu and Zn.

Sources of Chlorophenolic Compounds to the Fraser River Estuary

1988 ◽  
Vol 23 (1) ◽  
pp. 55-68 ◽  
Author(s):  
J. H. Carey ◽  
J. H. Hart
Keyword(s):  
River Flow ◽  
River Estuary ◽  
Low Flow ◽  
Fraser River ◽  
Pulp Mills ◽  
Flow Conditions ◽  
Downstream Site ◽  
Upstream Site ◽  
The North ◽  
Main River

Abstract The identity and concentrations of chlorophenolic compounds in the Fraser River estuary were determined under conditions of high and low river flow at three sites: a site upstream from the trifurcation and at downstream sites for each main river arm. Major chlorophenolics present under both flow regimes were 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP), pentachlorophenol (PCP), tetrachloroguaiacol (TeCG) and a compound tentatively identified as 3,4,5-trichloroguaiacol (3,4,5-TCG). Under high flow conditions, concentrations of the guaiacols were higher than any of the Chlorophenols and concentrations of all five chlorophenolics appeared to correlate. Under low flow conditions, concentrations of chloroguaiacols were higher than Chlorophenols at the upstream site and at the downstream site on the Main Arm, whereas at the downstream site on the North Arm, concentrations of 2,3,4,6-TeCP and PCP were higher than the chloroguaiacols in some samples. Overall, the results indicate that pulp mills upstream from the estuary are important sources of chlorophenolics to the estuary under all flow conditions. Additional episodic inputs of 2,3,4,6-TeCP and PCP from lumber mills occur along the North Arm. When these inputs occur, they can cause the concentrations of Chlorophenols in the North Arm to exceed provisional objectives. If chloroguaiacols are included as part of the objective, concentrations of total chlorophenolics in water entering the estuary can approach and exceed these objectives, especially under low flow conditions.

scholarly journals Calibration of hydrological models for ecologically relevant streamflow predictions: a trade-off between fitting well to data and estimating consistent parameter sets?

2020 ◽  
Vol 24 (3) ◽  
pp. 1031-1054 ◽  
Author(s):  
Thibault Hallouin ◽  
Michael Bruen ◽  
Fiachra E. O'Loughlin
Keyword(s):  
Flow Regime ◽  
River Flow ◽  
Freshwater Ecosystems ◽  
Living Environment ◽  
Rate Of Change ◽  
Low Flow ◽  
Hydrological Models ◽  
Flow Conditions ◽  
Local Flow ◽  
Trade Off

Abstract. The ecological integrity of freshwater ecosystems is intimately linked to natural fluctuations in the river flow regime. In catchments with little human-induced alterations of the flow regime (e.g. abstractions and regulations), existing hydrological models can be used to predict changes in the local flow regime to assess any changes in its rivers' living environment for endemic species. However, hydrological models are traditionally calibrated to give a good general fit to observed hydrographs, e.g. using criteria such as the Nash–Sutcliffe efficiency (NSE) or the Kling–Gupta efficiency (KGE). Much ecological research has shown that aquatic species respond to a range of specific characteristics of the hydrograph, including magnitude, frequency, duration, timing, and the rate of change of flow events. This study investigates the performance of specially developed and tailored criteria formed from combinations of those specific streamflow characteristics (SFCs) found to be ecologically relevant in previous ecohydrological studies. These are compared with the more traditional Kling–Gupta criterion for 33 Irish catchments. A split-sample test with a rolling window is applied to reduce the influence on the conclusions of differences between the calibration and evaluation periods. These tailored criteria are shown to be marginally better suited to predicting the targeted streamflow characteristics; however, traditional criteria are more robust and produce more consistent behavioural parameter sets, suggesting a trade-off between model performance and model parameter consistency when predicting specific streamflow characteristics. Analysis of the fitting to each of 165 streamflow characteristics revealed a general lack of versatility for criteria with a strong focus on low-flow conditions, especially in predicting high-flow conditions. On the other hand, the Kling–Gupta efficiency applied to the square root of flow values performs as well as two sets of tailored criteria across the 165 streamflow characteristics. These findings suggest that traditional composite criteria such as the Kling–Gupta efficiency may still be preferable over tailored criteria for the prediction of streamflow characteristics, when robustness and consistency are important.

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.

Non-stationarity of low flows and their relevance to river modelling during drought periods

2017 ◽  
Vol 68 (12) ◽  
pp. 2306 ◽  
Author(s):  
David W. Rassam ◽  
Daniel Pagendam ◽  
Mat Gilfedder ◽  
Lu Zhang
Keyword(s):  
Regression Analysis ◽  
River Flow ◽  
Low Flow ◽  
Flow Conditions ◽  
Low Flows ◽  
River Modelling ◽  
Quantile Regression Analysis ◽  
River Models ◽  
Groundwater Contribution ◽  
Ltb Metric

Changes in groundwater storage lead to a reduction in groundwater contribution to river flow and present as non-stationarity, especially during low-flow conditions. Conventional river models typically ignore this non-stationarity, and, hence, their predictions of declines in low flows during drought periods are likely to be compromised. The present study assesses non-stationarity and highlights its implications for river modelling. A quantile regression analysis showed non-stationarity of low flows in the Namoi catchment (Australia), with statistically significant downward trends in the 10th percentile of log-transformed baseflow (10-LTB). This highlighted the usefulness of the 10-LTB metric to identify non-stationarity and, hence, alert modellers to the importance of adopting models that explicitly account for groundwater processes when modelling such river systems.

Synchrony in population dynamics of juvenile Atlantic salmon: analyzing spatio-temporal variation and the influence of river flow and demography

2021 ◽  
Author(s):  
Colin Bouchard ◽  
Mathieu Buoro ◽  
Clément Lebot ◽  
Stephanie M Carlson
Keyword(s):  
Atlantic Salmon ◽  
Environmental Conditions ◽  
River Flow ◽  
Multiple Scales ◽  
Low Flow ◽  
Moran Effect ◽  
Spatial Synchrony ◽  
Flow Conditions ◽  
Spatio Temporal ◽  
Regional Synchrony

Dispersal and shared environmental conditions can both synchronize the dynamics of local populations, but disentangling their relative influence on dynamics is challenging. We used a Bayesian approach to estimate the synchrony of a metapopulation of Atlantic salmon composed of 18 populations in Brittany, France, including a 24-year time-series of the abundances of juveniles. We estimated the spatial synchrony at a regional and local spatial scale over the study period. We found a strong regional synchrony despite spatio-temporal variability of local synchrony in the abundance of juveniles. We then explored the drivers of synchrony, including environmental conditions (aspects of river flow) and abundance of adult breeders. This revealed that summer low-flow conditions seemed to synchronize the abundances of juveniles more than the synchrony in the abundance of adult breeders, suggesting a Moran effect. Given that drought conditions are expected to become more common with climate change, our work highlights the potentially strong synchronizing effect of summer low-flow on the dynamics of local salmon populations and the benefits of considering synchrony at multiple scales.

Geochemistry of Red Mountain Creek, Colorado, under low-flow conditions, August 2002

2005 ◽  
Author(s):  
Robert L. Runkel ◽  
Briant A. Kimball ◽  
Katherine Walton-Day ◽  
Philip L. Verplanck
Keyword(s):  
Low Flow ◽  
Flow Conditions

scholarly journals Forensic Investigation of Four Monitored Green Infrastructure Inlets

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1787
Author(s):  
Leena J. Shevade ◽  
Franco A. Montalto
Keyword(s):  
Measurement Uncertainty ◽  
Green Infrastructure ◽  
Stormwater Management ◽  
Catchment Area ◽  
Low Flow ◽  
Inflow Rate ◽  
Forensic Investigation ◽  
Flow Conditions ◽  
The Mean

Green infrastructure (GI) is viewed as a sustainable approach to stormwater management that is being rapidly implemented, outpacing the ability of researchers to compare the effectiveness of alternate design configurations. This paper investigated inflow data collected at four GI inlets. The performance of these four GI inlets, all of which were engineered with the same inlet lengths and shapes, was evaluated through field monitoring. A forensic interpretation of the observed inlet performance was conducted using conclusions regarding the role of inlet clogging and inflow rate as described in the previously published work. The mean inlet efficiency (meanPE), which represents the percentage of tributary area runoff that enters the inlet was 65% for the Nashville inlet, while at Happyland the NW inlet averaged 30%, the SW inlet 25%, and the SE inlet 10%, considering all recorded events during the monitoring periods. The analysis suggests that inlet clogging was the main reason for lower inlet efficiency at the SW and NW inlets, while for the SE inlet, performance was compromised by a reverse cross slope of the street. Spatial variability of rainfall, measurement uncertainty, uncertain tributary catchment area, and inlet depression characteristics are also correlated with inlet PE. The research suggests that placement of monitoring sensors should consider low flow conditions and a strategy to measure them. Additional research on the role of various maintenance protocols in inlet hydraulics is recommended.

Influence of climate change on low flow conditions. Case study: Laborec River, eastern Slovakia

2021 ◽  
Author(s):  
Katarzyna Kubiak-Wójcicka ◽  
Martina Zeleňáková ◽  
Peter Blištan ◽  
Dorota Simonová ◽  
Agnieszka Pilarska
Keyword(s):  
Climate Change ◽  
Low Flow ◽  
Flow Conditions

scholarly journals Soil microbial inoculation during flood events shapes headwater stream microbial communities and diversity

2021 ◽  
Author(s):  
Florian Caillon ◽  
Katharina Besemer ◽  
Peter Peduzzi ◽  
Jakob Schelker
Keyword(s):  
Microbial Diversity ◽  
Bacterial Diversity ◽  
Soil Water ◽  
Headwater Streams ◽  
High Flow ◽  
Low Flow ◽  
Flood Events ◽  
Flow Conditions ◽  
Soil Microbial ◽  
Microbial Inoculation

AbstractFlood events are now recognized as potentially important occasions for the transfer of soil microbes to stream ecosystems. Yet, little is known about these “dynamic pulses of microbial life” for stream bacterial community composition (BCC) and diversity. In this study, we explored the potential alteration of stream BCC by soil inoculation during high flow events in six pre-alpine first order streams and the larger Oberer Seebach. During 1 year, we compared variations of BCC in soil water, stream water and in benthic biofilms at different flow conditions (low to intermediate flows versus high flow). Bacterial diversity was lowest in biofilms, followed by soils and highest in headwater streams and the Oberer Seebach. In headwater streams, bacterial diversity was significantly higher during high flow, as compared to low flow (Shannon diversity: 7.6 versus 7.9 at low versus high flow, respectively, p < 0.001). Approximately 70% of the bacterial operational taxonomic units (OTUs) from streams and stream biofilms were the same as in soil water, while in the latter one third of the OTUs were specific to high flow conditions. These soil high-flow OTUs were also found in streams and biofilms at other times of the year. These results demonstrate the relevance of floods in generating short and reoccurring inoculation events for flowing waters. Moreover, they show that soil microbial inoculation during high flow enhances microbial diversity and shapes fluvial BCC even during low flow. Hence, soil microbial inoculation during floods could act as a previously overlooked driver of microbial diversity in headwater streams.

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