37 research outputs found

    Critical assessment and validation of a time-integrating fluvial suspended sediment sampler

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    Delivery of fine sediment to fluvial systems is of considerable concern given the physical and ecological impacts of elevated levels in drainage networks. Although it is possible to measure the transfer of fine sediment at high frequency by using a range of surrogate and automated technologies, the demands for assessing sediment flux and sediment properties at multiple spatially distributed locations across catchments can often not be met using established sampling techniques. The time-integrated mass-flux sampler (TIMS) has the potential to bridge this gap and further our understanding of fine sediment delivery in fluvial systems. However, these devices have undergone limited testing in the field. The aim of this paper was to provide a critical validation of TIMS as a technique for assessing fluvial fine sediment transfer. Fine sediment flux and sediment properties were assessed over 2 years with individual sampling periods of approximately 30 days. Underestimation of sediment flux ranged between 66% and 99% demonstrating that TIMS is unsuitable for assessing absolute sediment loads. However, assessment of relative efficiency showed that six of seven samplers produced statistically strong relationships with the reference sediment load (P < 0.05). Aggregated data from all sites produced a highly significant relationship between reference and TIMS loads (R2 = 0.80; P < 0.001) demonstrating TIMS may be suitable for characterizing patterns of suspended sediment transfer. Testing also illustrated a consistency in sediment properties between multiple samplers in the same channel cross section. TIMS offers a useful means of assessing spatial and temporal patterns of fine sediment transfer across catchments where expensive monitoring frameworks cannot be commissioned

    Bank erosion events and processes in the Upper Severn basin

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    This paper examines river bank retreat rates, individual erosion events, and the processes that drive them in the Upper Severn basin, mid-Wales, UK. Traditional erosion pin networks were used to deliver information on patterns of downstream change in erosion rates. In addition, the novel automatic Photo-Electronic Erosion Pin (PEEP) monitoring system was deployed to generate near-continuous data on the temporal distribution of bank erosion and accretion: this allowed focus on the magnitude and timing of individual erosional and depositional events in relation to specific flow episodes. Erosion dynamics data from throughout the Upper Severn basin are combined with detailed information on bank material properties and spatial change in channel hydraulics derived from direct field survey, to assess the relationships between flow properties and bank erosion rates. Results show that bank erosion rates generally increase downstream, but relate more strongly to discharge than to reach-mean shear stress, which peaks near the basin head. Downstream changes in erosion mechanisms and boundary materials, across the upland/lowland transition (especially the degree of development of composite bank material profiles), are especially significant. Examples of sequences of bank erosion events show how the PEEP system can (a) quantify the impact of individual, rather than aggregated, forcing events, (b) reveal the full complexity of bank response to given driving agents, including delayed erosion events, and (c) establish hypotheses of process-control in bank erosion systems. These findings have important implications for the way in which bank erosion problems are researched and managed. The complex responses demonstrated have special significance for the way in which bank processes and channel-margin sediment injections should be handled in river dynamics models

    Development of the Liverpool Adverse Drug Reaction Avoidability Assessment Tool

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    Aim To develop and test a new tool to assess the avoidability of adverse drug reactions that is suitable for use in paediatrics but which is also applicable to a variety of other settings. Methods The study involved multiple phases. Preliminary work involved using the Hallas scale and a modification of the existing Hallas scale, to assess two different sets of adverse drug reaction (ADR) case reports. Phase 1 defined, modified and refined a new tool using multidisciplinary teams. Phase 2 involved the assessment of 50 ADR case reports from a prospective study of paediatric inpatients by individual assessors. Phase 3 compared assessments with the new tool for individuals and groups in comparison to the ‘gold standard’ (the avoidability outcome set by a panel of senior investigators: an experienced clinical pharmacologist, paediatrician and pharmacist). Main Outcome Measures Inter-rater reliability (IRR), measure of disagreement and utilization of avoidability categories. Results Preliminary work—Pilot phase: results for the original Hallas cases were fair and pairwise kappa scores ranged from 0.21 to 0.36. Results for the modified Hallas cases were poor, pairwise kappa scores ranged from 0.06 to 0.16. Phase 1: on initial use of the new tool, agreement between the two multidisciplinary groups was found on 13/20 cases with a kappa score of 0.29 (95% CI -0.04 to 0.62). Phase 2: the assessment of 50 ADR case reports by six individual reviewers yielded pairwise kappa scores ranging from poor to good 0.12 to 0.75 and percentage exact agreement (%EA) ranged from 52–90%. Phase 3: Percentage exact agreement ranged from 35–70%. Overall, individuals had better agreement with the ‘gold standard’. Conclusion Avoidability assessment is feasible but needs careful attention to methods. The Liverpool ADR avoidability assessment tool showed mixed IRR. We have developed and validated a method for assessing the avoidability of ADRs that is transparent, more objective than previous methods and that can be used by individuals or groups

    How are Research for Development Programmes Implementing and Evaluating Equitable Partnerships to Address Power Asymmetries?

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    The complexity of issues addressed by research for development (R4D) requires collaborations between partners from a range of disciplines and cultural contexts. Power asymmetries within such partnerships may obstruct the fair distribution of resources, responsibilities and benefits across all partners. This paper presents a cross-case analysis of five R4D partnership evaluations, their methods and how they unearthed and addressed power asymmetries. It contributes to the field of R4D partnership evaluations by detailing approaches and methods employed to evaluate these partnerships. Theory-based evaluations deepened understandings of how equitable partnerships contribute to R4D generating impact and centring the relational side of R4D. Participatory approaches that involved all partners in developing and evaluating partnership principles ensured contextually appropriate definitions and a focus on what partners value

    How are Research for Development Programmes Implementing and Evaluating Equitable Partnerships to Address Power Asymmetries?

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    The complexity of issues addressed by research for development (R4D) requires collaborations between partners from a range of disciplines and cultural contexts. Power asymmetries within such partnerships may obstruct the fair distribution of resources, responsibilities and benefits across all partners. This paper presents a cross-case analysis of five R4D partnership evaluations, their methods and how they unearthed and addressed power asymmetries. It contributes to the field of R4D partnership evaluations by detailing approaches and methods employed to evaluate these partnerships. Theory-based evaluations deepened understandings of how equitable partnerships contribute to R4D generating impact and centring the relational side of R4D. Participatory approaches that involved all partners in developing and evaluating partnership principles ensured contextually appropriate definitions and a focus on what partners value. The online version contains supplementary material available at 10.1057/s41287-023-00578-w. [Abstract copyright: © The Author(s) 2023.

    Americans, Marketers, and the Internet: 1999-2012

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    Assessing the Effectiveness of Sustainable Drainage Systems (SuDS): Interventions, Impacts and Challenges

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    Sustainable drainage systems (SuDS) can be a key tool in the management of extremes of rainfall, due to their capacity to attenuate and treat surface water. Yet, implementation is a complex process, requiring buy-in from multiple stakeholders. Buy-in is often undermined by a lack of practical evidence and monitoring of implemented SuDS. In this paper, we present a collaborative case study between a local authority, university and the UK Environment Agency. This partnership approach enabled the installation of SuDS and monitoring equipment to address surface runoff in the north east of England. Ultrasonic sensors were installed in the drainage network to evaluate the attenuation of surface water. SuDS were installed during an atypically wet spring, followed by a hot and dry summer, providing a range of conditions to assess their performance. Results demonstrate that there was a statistically significant difference in the detected flow level in manholes downstream of the SuDS interventions. Several challenges occurred, from signal obstacles in wireless telecommunication services, to logistical constraints of installing sensors in the drainage network, and issues with the adoption of property level SuDS. These issues require further research. Qualitative support for partnership working was crucial to increase the capacity for delivering SuDS. To ensure the success of future schemes and likelihood of SuDS uptake, partnership working and engaging with communities is vita

    Interbasin water transfer in a changing world: A new conceptual model

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    Water scarcity is a global issue, affecting in excess of four billion people. Interbasin Water Transfer (IBWT) is an established method for increasing water supply by transferring excess water from one catchment to another, water-scarce catchment. The implementation of IBWT peaked in the 1980s and was accompanied by a robust academic debate of its impacts. A recent resurgence in the popularity of IBWT, and particularly the promotion of mega-scale schemes, warrants revisiting this technology. This paper provides an updated review, building on previously published work, but also incorporates learning from schemes developed since the 1980s. We examine the spatial and temporal distribution of schemes and their drivers, review the arguments for and against the implementation of IBWT schemes and examine conceptual models for assessing IBWT schemes. Our analysis suggests that IBWT is growing in popularity as a supply-side solution for water scarcity and is likely to represent a key tool for water managers into the future. However, we argue that IBWT cannot continue to be delivered through current approaches, which prioritise water-centric policies and practices at the expense of social and environmental concerns. We critically examine the Socio-Ecological Systems and Water-Energy-Food (WEF) Nexus models as new conceptual models for conceptualising and assessing IBWT. We conclude that neither model offers a comprehensive solution. Instead, we propose an enhanced WEF model (eWEF) to facilitate a more holistic assessment of how these mega-scale engineering interventions are integrated into water management strategies. The proposed model will help water managers, decision-makers, IBWT funders and communities create more sustainable IBWT schemes

    The effect of riparian pool-riffles on the hydrochemistry of hyporheic habitats: The River Esk, Yorkshire, UK.

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    European Union Water Framework Directive (WFD) (2000/60/EC) waterbody statuses are often derived from the assemblage of mixed-taxon organisms found within bed sediments. Yet no routine water chemistry samples are taken from riverbed substrate, despite many interstitial species being dependant on specific physicochemical conditions. This paper examines water and nutrient exchanges between stream and substrate, the hyporheic zone, and the consequent alteration to the chemistry of interstitial and in-stream waters, which in turn leads to small-scale but significant changes in habitat. Bed topography, principally a pool-riffle sequence, was surveyed and hydraulically sampled to examine the hyporheic flow pathways generated between the stream, substrate, and groundwater—creating an ecotone. Hyporheic zone, in-stream and groundwater hydrochemistry, and hydraulic measures were assessed at a braided woodland river reach using a dense monitoring approach. The findings demonstrate that through a 23-m pool-riffle sequence, where water infiltrates at the riffle-head and subsequently exfiltrates at the riffle-tail, there is a 5% reduction in mean in-stream nitrate-N and a 73% reduction in hyporheic zone concentration. When calcium-enriched riffle-tail exfiltrate meets riffle-runoff water that is turbulently oxygenated from riffle-flow, an interstitial redoxcline is created. Dissolved oxygen nocturnally drops, with photosynthetic rate reduction, which causes hyporheic nitrate-N to double its daytime concentration. The results are related to the Yorkshire River Esk freshwater pearl mussels, Margaritifera margaritifera Linnaeus (1758), a declining endangered species. At present, scant monitoring of interstitial hydrochemistry and diurnal change across stream and substrate occurs
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