scholarly journals Reduced fine sediment flux in response to the managed diversion of an upland river channel

2015 ◽  
Vol 3 (4) ◽  
pp. 1179-1220
Author(s):  
M. T. Perks ◽  
J. Warburton
Keyword(s):  
Suspended Sediment ◽  
Fine Sediment ◽  
Sediment Flux ◽  
Analysis Of Covariance ◽  
Before And After ◽  
Suspended Sediment Concentrations ◽  
Sediment Transfer ◽  
The Uk ◽  
The Impact ◽  
B Coefficients

Abstract. This paper describes the implementation of a novel mitigation approach and subsequent adaptive management, designed to reduce the transfer of fine sediment in Glaisdale Beck; a small upland catchment in the UK. Hydro-meteorological and suspended sediment datasets are collected over a two year period spanning pre- and post-diversion periods in order to assess the impact of the channel reconfiguration scheme on the fluvial suspended sediment dynamics. Analysis of the river response demonstrates that the fluvial sediment system has become more restrictive with reduced fine sediment transfer. This is characterised by reductions in flow-weighted mean suspended sediment concentrations from 77.93 mg L−1 prior to mitigation, to 74.36 mg L−1 following the diversion. A Mann–Whitney U test found statistically significant differences (p < 0.001) between the pre- and post-monitoring median SSCs. Whilst application of one-way analysis of covariance (ANCOVA) on the coefficients of sediment rating curves developed before and after the diversion found statistically significant differences (p < 0.001), with both Log a and b coefficients becoming smaller following the diversion. Non-parametric analysis indicates a reduction in residuals through time (p < 0.001), with the developed LOWESS model over-predicting sediment concentrations as the channel stabilises. However, the channel is continuing to adjust to the reconfigured morphology, with evidence of a headward propagating knickpoint which has migrated 120 m at an exponentially decreasing rate over the last 7 years since diversion. The study demonstrates that channel reconfiguration can be effective in mitigating fine sediment flux in upland streams but the full value of this may take many years to achieve whilst the fluvial system, slowly readjusts.

scholarly journals Reduced fine sediment flux and channel change in response to the managed diversion of an upland river channel

2016 ◽  
Vol 4 (3) ◽  
pp. 705-719 ◽  
Author(s):  
Matthew Thomas Perks ◽  
Jeff Warburton
Keyword(s):  
Suspended Sediment ◽  
Fine Sediment ◽  
Sediment Flux ◽  
Analysis Of Covariance ◽  
Data Sets ◽  
Before And After ◽  
Suspended Sediment Concentrations ◽  
Sediment Data ◽  
The Uk ◽  
The Impact

Abstract. This paper describes the implementation of a novel mitigation approach and subsequent adaptive management, designed to reduce the transfer of fine sediment (< 2 mm) in Glaisdale Beck, a small, predominantly upland catchment in the UK. Hydro-meteorological and suspended sediment data sets are collected over a 2-year period spanning pre- and post-diversion periods in order to assess the impact of the channel reconfiguration scheme on the fluvial suspended sediment dynamics. Analysis of the river response demonstrates that the fluvial sediment system has become more restrictive with reduced fine sediment transfer. This is characterized by reductions in flow-weighted mean suspended sediment concentrations from 77.93 mg L−1 prior to mitigation, to 74.36 mg L−1 following the diversion. A Mann–Whitney U test found statistically significant differences (p < 0.001) between the pre- and post-monitoring median suspended sediment concentrations (SSCs). Whilst application of one-way analysis of covariance (ANCOVA) on the coefficients of sediment rating curves developed before and after the diversion found statistically significant differences (p < 0.001), with both Loga and b coefficients becoming smaller following the diversion. Non-parametric analysis indicates a reduction in residuals through time (p < 0.001), with the developed LOWESS model over-predicting sediment concentrations as the channel stabilizes. However, the channel is continuing to adjust to the reconfigured morphology, with evidence of a headward propagating knickpoint which has migrated 120 m at an exponentially decreasing rate over the last 7 years since diversion. The study demonstrates that channel reconfiguration can be effective in mitigating fine sediment flux in headwater streams but the full value of this may take many years to achieve whilst the fluvial system slowly readjusts.

scholarly journals The impact of tides and waves on near-surface suspended sediment concentrations in the English Channel

Oceanologia ◽  
2017 ◽  
Vol 59 (1) ◽  
pp. 28-36 ◽  
Author(s):  
Nicolas Guillou ◽  
Aurélie Rivier ◽  
Georges Chapalain ◽  
Francis Gohin
Keyword(s):  
Suspended Sediment ◽  
English Channel ◽  
Near Surface ◽  
Suspended Sediment Concentrations ◽  
The Impact

scholarly journals Impact of Climate Change on Metal and Suspended Sediment Concentrations in Urban Waters

2020 ◽  
Vol 8 ◽  
Author(s):  
Paul Frogner-Kockum ◽  
Gunnel Göransson ◽  
Marie Haeger-Eugensson
Keyword(s):  
Climate Change ◽  
Suspended Sediment ◽  
Contaminant Transport ◽  
Dry Period ◽  
Short Term ◽  
Impact Of Climate Change ◽  
Suspended Sediment Concentrations ◽  
River Loads ◽  
Metal Contaminant ◽  
The Impact

In order to study the impact of climate change on metal contaminant transport in urban waters and its relevance for water quality, we have analyzed variations in metal- and suspended sediment concentrations (SSC) in three urban rivers and one small creek in the Gothenburg region during various hydrological events such as spring flood, dry period, and wet period. To interpret river loads of metals and SSC we have furthermore followed meteorological trends since 1961 and additionally calculated future trends for the Gothenburg region, located on the west coast of Sweden. During periods of a short-term increase in precipitation we found an increased particle bound metal transport in urban watercourses of the Göta Älv River. In addition, a correlation between studied parameters indicates that surface runoff from brownfields most likely is the main source to the increased transport of pollutants in river systems rather than re-suspension of polluted river sediment.

scholarly journals WHEN SEXUAL INFIDELITY TRIGGERS MURDER: EXAMINING THE IMPACT OF HOMICIDE LAW REFORM ON JUDICIAL ATTITUDES IN SENTENCING

2015 ◽  
Vol 74 (2) ◽  
pp. 307-328 ◽  
Author(s):  
Jeremy Horder ◽  
Kate Fitz-Gibbon
Keyword(s):  
Case Law ◽  
Law Reform ◽  
Loss Of Control ◽  
Sexual Infidelity ◽  
Before And After ◽  
Key Features ◽  
Homicide Law ◽  
The Uk ◽  
Substantive Law ◽  
The Impact

AbstractIn October 2010, the UK Parliament brought into effect law that replaced the partial defence to murder of provocation with a new partial defence of “loss of control”, applicable to England, Wales, and Northern Ireland. Although it retained some key features of its controversial predecessor, the new partial defence was in part designed better to address the gendered contexts within which a large number of homicides are committed. In examining the impact of the reforms, we will focus on long-held concerns about the treatment of sexual infidelity as a trigger for loss of control in murder cases. The article undertakes an analysis of English case law to evaluate the way in which sexual infidelity-related evidence has influenced perceptions of a homicide defendant's culpability, for the purposes of sentencing, both before and after the implementation of reform. The analysis reveals that, in sentencing offenders post reform, the higher courts have failed to follow the spirit of the reforms respecting the substantive law by effecting a corresponding change in sentencing practice.

scholarly journals Suspended sediment fluxes in an Indonesian river draining a rainforested basin subject to land cover change

2011 ◽  
Vol 8 (4) ◽  
pp. 7137-7175 ◽  
Author(s):  
F. A. Buschman ◽  
A. J. F. Hoitink ◽  
S. M. de Jong ◽  
P. Hoekstra
Keyword(s):  
Land Cover ◽  
Suspended Sediment ◽  
River Discharge ◽  
Soil Loss ◽  
Suspended Sediment Concentration ◽  
Sediment Concentration ◽  
Sediment Flux ◽  
Sediment Fluxes ◽  
Suspended Sediment Flux ◽  
The Impact

Abstract. Forest clearing for reasons of timber production, open pit mining and the establishment of oil palm plantations generally results in excessively high sediment loads in the tropics. The increasing sediment fluxes pose a threat to coastal marine ecosystems such as coral reefs. This study presents observations of suspended sediment fluxes in the Berau river (Indonesia), which debouches into a coastal ocean that can be considered the preeminent center of coral diversity. The Berau is an example of a small river draining a mountainous, relatively pristine basin that receives abundant rainfall. Flow velocity was measured over a large part of the river width at a station under the influence of tides, using a Horizontal Acoustic Doppler Current Profiler (HADCP). Surrogate measurements of suspended sediment concentration were taken with an Optical Backscatter Sensor (OBS). Tidally averaged suspended sediment concentration increases with river discharge, implying that the tidally averaged suspended sediment flux increases non-linearly with river discharge. Averaged over the 6.5 weeks observations covered by the benchmark survey, the tidally averaged suspended sediment flux was estimated at 2 Mt y−1. Considering the wet conditions during the observation period, this figure may be considered as an upper limit of the yearly averaged flux. This flux is significantly smaller than what could have been expected from the characteristics of the catchment. The consequences of ongoing clearing of rainforest were explored using a plot scale erosion model. When rainforest, which still covered 50–60 % of the basin in 2007, is converted to production land, soil loss is expected to increase with a factor between 10 and 100. If this soil loss is transported seaward as suspended sediment, the increase in suspended sediment flux in the Berau river would impose a severe sediment stress on the global hotspot of coral reef diversity. The impact of land cover changes will largely depend on the degree in which the Berau estuary acts as a sediment trap.

scholarly journals Exploring overcrowding trends in an inner city emergence department in the UK before and during COVID-19 epidemic

2021 ◽  
Author(s):  
J Panovska-Griffiths ◽  
J Ross ◽  
S Elkhodair ◽  
C Baxter-Derrington ◽  
C Laing ◽  
...  
Keyword(s):  
Waiting Time ◽  
Hospital Emergency ◽  
Number Of Patients ◽  
Before And After ◽  
Ed Overcrowding ◽  
University College London ◽  
Flow Through ◽  
Multifaceted Interventions ◽  
The Uk ◽  
The Impact

AbstractBackgroundWe compared impact of three pre-COVID-19 interventions and of the COVID-19 UK-epidemic and the first UK national lockdown on overcrowding within University College London Hospital Emergency Department (UCLH ED). The three interventions: target the influx of patients at ED (A), reduce the pressure on in-patients’ beds (B) and improve ED processes to improve the flow of patents out from ED (C).MethodsWe analysed the change in overcrowding metrics (daily attendances, the proportion of people leaving within four hours of arrival (four-hours target) and the reduction in overall waiting time) across three analysis. The first analysis used data 01/04/2017-31/12-2019 to calculate changes over a period of six months before and after the start of interventions A-C. The second and third analyses focused on evaluating the impact of the COVID-19 epidemic, comparing the first 10 months in 2020 and 2019, and of the first national lockdown (23/03/2020-31/05/2020).ResultsPre-COVID-19 all interventions led to small reductions in waiting time (17%, p<0.001 for A and C;9%, p=0.322 for B) but also to a small decrease in the number of patients leaving within four hours of arrival (6.6%,7.4%,6.2% respectively A-C,p<0.001).In presence of the COVID-19 pandemic, attendance and waiting time were reduced (40% and 8%;p<0.001), and the number of people leaving within four hours of arrival was increased (6%,p<0.001). During the first lockdown, there was 65% reduction in attendance, 22% reduction in waiting time and 8% increase in number of people leaving within 4 hours of arrival (p<0.001). Crucially, when the lockdown was lifted, there was an increase (6.5%,p<0.001) in the percentage of people leaving within four hours, together with a larger (12.5%,p<0.001) decrease in waiting time. This occurred despite the increase of 49.6%(p<0.001) in attendance after lockdown ended.ConclusionsThe mixed results pre-COVID-19 (significant improvements in waiting time with some interventions but not improvement in the four-hours target), may be due to a ‘spill-over effect’ where clogging up one part of the ED system affects other parts. Hence multifaceted interventions and a system-wide approach to improve the pathway of flow through the ED system is necessary.During 2020 and in presence of the COVID-19 epidemic, a shift in public behaviour with anxiety over attending hospitals and higher use of virtual consultations, led to notable drop in UCLH ED attendance and consequential curbing of overcrowding.Importantly, once the lockdown was lifted, although there was an increase in arrivals at UCLH ED, overcrowding metrics were reduced. Thus, the combination of shifted public behaviour and the restructuring changes during COVID-19 epidemic, maybe be able to curb future ED overcrowding, but longer timeframe analysis is required to confirm this.

scholarly journals The Reception Process in Ireland and the United Kingdom

2008 ◽  
Author(s):  
Samantha Besson
Keyword(s):  
United Kingdom ◽  
Legal Order ◽  
The United Kingdom ◽  
Before And After ◽  
The Uk ◽  
The Impact

This chapter examines the reception of the ECHR in the UK and Ireland both before and after incorporation. Both countries incorporated the ECHR using roughly the same model. One might have assumed that the mode of incorporation into a dualist legal order would largely determine outcomes. In Ireland and the UK, however, the impact of acts of incorporation was heavily mediated by pre-existing constitutional structure and practice.

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