Browsing by Author "Adams, Russell"

Now showing 1 - 3 of 3
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    Evaluating scenarios to reduce phosphorus transport in surface waters from slurry applications in temperate grasslands
    (Taylor & Francis (Informa), 2022-05-30) Adams, Russell; Doody, Donnacha; Anderson, Aine; Fenton, Owen; Tuohy, Pat; Vadas, Peter
    This study evaluates a range of scenarios to reduce soluble reactive phosphorus (SRP) losses using the surface runoff phosphorus transport model (Surphos) to simulate the application of liquid manure (slurry) to grassland catchments. Surphos was applied using data from two contrasting sites in the Republic of Ireland and Northern Ireland. It explored scenarios that investigated changes to the timing of slurry applications, based both on policy (i.e. a “closed” period where regulations prohibit any slurry spreading) and on climate-based restrictions, where soil moisture and antecedent rainfall were important factors. The observed data showed a considerable spatial variability in runoff at both sites, which resulted in a corresponding variable range of SRP losses predicted by the model. However, at both sites the model results showed that maintaining a closed period led to a greater reduction in SRP losses than opening this period up to slurry applications under climate-based restrictions.
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    The Role of Runoff Attenuation Features (RAFs) in Natural Flood Management
    (MDPI, 2022-11-23) Quinn, Paul Francis; Hewett, Caspar J.M.; Wilkinson, Mark E.; Adams, Russell
    Natural Flood Management (NFM) and catchment-based solutions for flood risk management and environmental problems are wide-ranging and complex. Management of fluvial flood risk in the UK is undergoing a fundamental shift, with a change in emphasis from solely working with structural defences to considering catchment-based measures which attenuate flood runoff. At the heart of this change are NFM and nature-based solutions. One key type of intervention is the Runoff Attenuation Feature (RAF): a class of features that targets runoff flow pathways and creates new temporary flow storage (such as ponds and leaky barriers). However, there is currently a lack of evidence for the effectiveness of NFM and RAFs at larger catchment scales and for managing extreme flood events. Nevertheless, there is a strong evidence base to suggest that well-designed RAFs deliver a range of ecosystem services if installed in the correct location. This paper reviews and critiques the role of RAFs and NFM as an interventionist and holistic approach to lowering runoff rates. The link between RAF design types and their relationship to land use and scale is made. Recent novel innovations and attempts to scale up RAFs are discussed. The role of antecedent conditions, groundwater and the change in residence time of processes is highlighted. The uncertainty and complexity of proving NFM effectiveness underpin a view that new thinking in catchment flood management is needed. New research is required, and many questions are raised about RAFs and NFM. The direction of travel is that a positive and proactive NFM community can now embrace the problem. Proof that RAFs and NFM can address flood management is not likely to be resolved without a great deal of further research but confidence that RAFs do beneficial work is growing and an argument for greater amounts of runoff attenuation is made.
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    Simulating Phosphorus Load Reductions in a Nested Catchment Using a Flow Pathway-Based Modeling Approach
    (MDPI, 2023-09-14) Adams, Russell; Quinn, Paul; Environmental Protection
    Catchment models are essential tools to identify and predict water quality problems linked to excessive nutrient applications (in this case phosphorus (P)). The Catchment Runoff Attenuation Flux Tool (CRAFT) has been successfully used to model nutrient fluxes and concentrations in north-western European catchments. The model is extremely parsimonious due to the relatively small number of parameters. However, an improvement to the representation of soluble P and particulate P fluxes in the fast-subsurface and surface runoff flow pathways was required. A case study in the north of Ireland applied the original and the new, enhanced (Dynamic) version of the CRAFT to the trans-border Blackwater catchment (UK and Republic of Ireland) covering nearly 1500 km2, with the land use predominantly livestock grazing. The larger size of the Blackwater also required a nested modeling approach to be implemented using a multiple sub-catchment variant (MultiCRAFT). P load reductions in the different sub-catchments were first identified using a simple approach based on the gap between the Water Framework Directive (WFD) limits for “Good” ecological status for soluble reactive P (SRP) concentrations and the recently observed concentrations. Modeling of different mitigation scenarios was then conducted using the MultiCRAFT framework with the best-performing variant of the CRAFT model embedded. The catchment was found to have flashy, episodic delivery of high concentrations of SRP and PP during runoff events which will require different sources (i.e., diffuse and point) of P to be targeted to achieve the WFD targets by the end of the decade. The modeling results thus showed that the required SRP load reductions could be best achieved using a combined scenario of mitigation measures that targeted diffuse sources contributing to both the surface runoff and fast-subsurface flow pathways, with point sources also identified as needing reduction in some sub-catchments.