94 research outputs found

    Acoustics of weirs: Potential implications for micro-hydropower noise.

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    There is great potential for the expansion of the small or micro scale hydropower network. Of the 43 thousand weirs in the UK there are only 500 consented hydro schemes. Planning applications for such schemes require a noise assessment. Noise evaluation of a proposed renewable scheme is often complicated by the turbine sites having distinct noise characteristics in the first instance, which are often caused by the weirs themselves. Three types of weir were studied: Broad Crest weirs were studied in detail; this is complimented by further studies in Flat V and Crump weirs. Flow data was collected for ten sites from the Environment Agency and the National Rivers Flow Archive to assess the collected Sound Pressure Level (SPL) and calculated Sound poWer Level (SWL) in relation to various river flows. Weir head height, width and meteorological data were also collected. It has been shown that the SPL data collection method used was the right choice, as the greatest amplitudes at the water impact interface at all weir types was recorded. SPL and SWL were found to be within a 36e82 dBz and 45e86 dBz range respectively for all weir types. These values can be used in computer simulations of sound propagation. The mean SPL and SWL difference between the weir types are 6.1 dBz and 6.3 dBz. Head height has the greatest effect on SPLs. Attenuation with distance was found to be similar to that of a free field line source in general

    Qualitative impact assessment of land management interventions on Ecosystem Services (“QEIA”). Report 3.7: Cultural Services

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    The focus of this project was to provide a rapid qualitative assessment of land management interventions on Ecosystem Services (ES) proposed for inclusion in Environmental Land Management (ELM) schemes. This involved a review of the current evidence base by ten expert teams drawn from the independent research community in a consistent series of ten Evidence Reviews. These reviews were undertaken rapidly at Defra’s request and together captured more than 2000 individual sources of evidence. These reviews were then used to inform an Integrated Assessment (IA) to provide a more accessible summary of these evidence reviews with a focus on capturing the actions with the greatest potential magnitude of change for the intended ES and their potential co-benefits and trade-offs across the Ecosystem Services and Ecosystem Services Indicators. The final IA table captured scores for 741 actions across 8 Themes, 33 ES and 53 ES-indicators. This produced a total possible matrix of 39,273 scores. It should be noted that this piece of work is just one element of the wider underpinning work Defra has commissioned to support the development of the ELM schemes. The project was carried out in two phases with the environmental and provisioning services commissioned in Phase 1 and cultural and regulatory services in a follow-on Phase 2. Due to the urgency of the need for these evidence reviews, there was insufficient time for systematic reviews and therefore the reviews relied on the knowledge of the team of the peer reviewed and grey literature with some rapid additional checking of recent reports and papers. This limitation of the review process was clearly explained and understood by Defra. The review presented here is one of the ten evidence reviews which informed the IA

    Comparing cost-effectiveness of surface water flood management interventions in a UK catchment

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    This is the final published version. Available from Wiley via the DOI in this record.Despite significant consequences caused by recent events, surface water flooding has historically been of lower priority relative to fluvial and coastal risks in UK flood management. Legislation and research proposes a variety of innovative interventions to address this; however, widespread application of these remains a challenge due to a number of institutional, economic, and technical barriers. This research applies a framework capable of fast and high-resolution assessment of intervention cost-effectiveness as an opportunity to improve available evidence and encourage uptake of interventions through analysing permutations of type, scale, and distribution in urban catchments. Fast assessment of many scenarios is achieved using a cellular automata flood model and a simplified representation of interventions. Conventional and green strategies are examined across a range of design standard and high-magnitude rainfall events in an urban catchment. Results indicate high-volume rainwater capture interventions demonstrate a significant reduction in estimated annual damage costs, and localised surface water drainage interventions exhibit high cost-effectiveness for damage reduction. Analysis of performance across a wide range of return periods enhances available evidence for option comparison decision support and provides a basis for future resilience assessment of interventions.Engineering and Physical Sciences Research Council (EPSRC

    Has Scots pine (Pinus sylvestris) co-evolved with Dothistroma septosporum in Scotland? Evidence for spatial heterogeneity in the susceptibility of native provenances

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    Spatial heterogeneity in pathogen pressure leads to genetic variation in, and evolution of, disease-related traits among host populations. In contrast, hosts are expected to be highly susceptible to exotic pathogens as there has been no evolution of defence responses. Host response to pathogens can therefore be an indicator of a novel or endemic pathosystem. Currently, the most significant threat to native British Scots pine (Pinus sylvestris) forests is Dothistroma needle blight (DNB) caused by the foliar pathogen Dothistroma septosporum which is presumed to be exotic. A progeny–provenance trial of 6-year-old Scots pine, comprising eight native provenances each with four families in six blocks, was translocated in April 2013 to a clear-fell site in Galloway adjacent to a DNB-infected forest. Susceptibility to D. septosporum, measured as DNB severity (estimated percentage nongreen current-year needles), was assessed visually over 2 years (2013–2014 and 2014–2015; two assessments per year). There were highly significant differences in susceptibility among provenances but not among families for each annual assessment. Provenance mean susceptibility to D. septosporum was negatively and significantly associated with water-related variables at site of origin, potentially due to the evolution of low susceptibility in the host in response to high historical pathogen pressure

    Qualitative Impact Assessment of Land Management Interventions on Ecosystem Services (“QEIA”). Report-1: Executive Summary: QEIA Evidence Review & Integrated Assessment

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    The focus of this project was to provide an expert-led, rapid qualitative assessment of land management interventions on Ecosystem Services (ES) proposed for inclusion in Environmental Land Management (ELM) schemes. This involved a review of the current evidence base for 741 land management actions on 33 Ecosystem Services and 53 Ecosystem Service indicators by ten teams involving 45 experts drawn from the independent research community in a consistent series of Evidence Reviews covering the broad topics of: • Air quality • Greenhouse gas emissions • Soils • Water management • Biodiversity: croplands • Biodiversity: improved grassland • Biodiversity: semi-natural habitats • Biodiversity: integrated systems-based actions • Carbon sequestration • Cultural services (including recreation, geodiversity and regulatory services). It should be noted that this piece of work is just one element of the wider underpinning work Defra has commissioned to support the development of the ELM schemes

    Designing an environmental flow framework for impounded river systems through modelling of invertebrate habitat quality

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    Many rivers have undergone flow modification by impoundments to provide services such as water supply and hydropower. There is an established consensus that typical modified flow regimes do not sufficiently cater to the needs of downstream ecosystems, and more must be done to understand and mitigate their associated impacts. This study presents a novel, transferable framework by which a small-scale impoundment in North West England is assessed through the use of linked hydro-ecological modelling in SRH-2D and CASiMiR, utilising flow velocity measurements and macroinvertebrate sampling data. Model predictions of habitat quality were supplemented by established ecological principles such as the importance of flow heterogeneity. Results are used to design environmental flow regimes, with the aim of improving ecological metrics whilst considering conflicting water demands. Based on an analysis of historical flow records, the implementation of designer flows over a 12 month period demonstrated increased peak species habitat qualities of 23–26%, characteristics such as flow heterogeneity were more naturalised, and 22% less water was released from the impoundment. Should outcomes be validated by in-stream flow experiment, there is great potential for further development and application of this method, including regional transferability for the rapid designation of environmental flows across a number of sites of similar magnitude and geography

    Qualitative impact assessment of land management interventions on Ecosystem Services (‘QEIA’). Report-2: Integrated Assessment

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    The focus of this project was to provide an expert-led, rapid qualitative assessment of land management interventions on Ecosystem Services (ES) proposed for inclusion in Environmental Land Management (ELM) schemes. This involved a review of the current evidence base for 741 land management actions on 33 Ecosystem Services and 53 Ecosystem Service indicators by ten expert teams drawn from the independent research community in a consistent series of ten Evidence Reviews covering the broad topics of; • Air quality • Greenhouse gas emissions • Soils • Water management • Biodiversity: croplands • Biodiversity: improved grassland • Biodiversity: semi-natural habitats • Biodiversity: integrated systems-based actions • Carbon sequestration • Cultural services (including recreation, geodiversity and regulatory services) These reviews were undertaken rapidly at Defra’s request by ten teams involving 45 experts who together captured more than 2,400 individual sources of evidence. This was followed by the Integrated Assessment (IA) reported here to provide a more accessible summary of these evidence reviews with a focus on capturing the actions with the greatest potential magnitude of change for the intended ES, and their potential co-benefits and trade-offs for the other ES

    Climate change indicators for Wales Review of options for monitoring changes in the Welsh climate

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    English/Welsh text on inverted pages. Summary of a of a technical report produced for the National Assembly for WalesAvailable from British Library Document Supply Centre-DSC:m02/17480 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
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