Browsing by Author "Pritchard, Oliver G."
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Item Open Access Enhanced visualization of the flat landscape of the Cambridgeshire Fenlands(Wiley, 2015-09-15) Pritchard, Oliver G.; Farewell, Timothy S.; Hallett, Stephen H.The Fenlands of East Anglia, England, represent a subtle landscape, where topographic highs rarely exceed 30 m above sea level. However, the fens represent an almost full sequence of Quaternary deposits which, together with islands of Cretaceous and Jurassic outcrops, make the area of geological importance. This feature discusses the advantages of using 3D visualization coupled with high-resolution topographical data, over traditional 2D techniques, when undertaking an analysis of the landscape. Conclusions suggest that the use of 3D visualization will result in a higher level of engagement, particularly when communicating geological information to a wider public.Item Open Access Forward-looking climatic scenarios of UK clay-related subsidence risk(Cranfield University, 2015-06-01) Hallett, Stephen H.; Farewell, Timothy; Pritchard, Oliver G.An award drawing upon the Cranfield University EPSRC-funded Impact Acceleration Account (IAA) was awarded to staff in the University’s School of Energy, Environment and Agrifood (SEEA) (Hallett, Farewell, Pritchard), to undertake processing of UKCP09 climate projections for the United Kingdom (UK) in support of assessments of future geohazards and societal impact. This report identifies the technical outcomes from this work and presents the resultant climate change cartography and related data. Spatially coherent national data ensembles are generated for the UKCP09 ‘Baseline’ period, for ‘2030’ and ‘2050’. Maps of Potential Soil Moisture Deficit (PSMD) are produced for each to exemplify its application. The findings suggest that the extremes in PSMD observed at the current time in the UK are likely to become the norm by 2030 and 2050. The data produced has a range of potential applications, from geohazard assessments to the built environment and infrastructure, to agri-informatic modelling of agricultural crops, as well as modelling for 'future-proofing' of buildings against predicted climate change by example. It is anticipated that the datasets presented from this IAA will be of benefit to a range of end-user stakeholders. One example is in the insurance, reinsurance and water utility sectors, where modelling of future impacts of climate change are conducted. Recent research has suggested this data will likely prove of use for County Councils and municipal authorities, for example in the allocation of targeted road maintenance funding, particularly on local-authority owned highways. Rail network operators, having faced a number of embankment failures, and track undulations as a result of shrink/swell activity are also likely to benefit from this research. The soil moisture deficit scenarios produced could help such organisations better manage geotechnical assets and vegetation management of susceptible slopes and soils. Cranfield’s School of Energy, Environment and Agrifood (SEEA) manage and operate the Natural Perils Directory (NPD). The NPD is a widely used geohazard thematic dataset portraying vulnerabilities arising from soil-climate responses to long-term climate change. NPD will incorporate directly the datasets produced and described here.Item Open Access How the impacts of burst water mains are influenced by soil sand content(European Geosciences Union (EGU) / Copernicus Publications, 2018-11-09) Farewell, Timothy S.; Jude, Simon; Pritchard, Oliver G.Society relies on infrastructure, but as infrastructure systems are often collocated and interdependent, they are vulnerable to cascading failures. This study investigated cross-infrastructure and societal impacts of burst water mains, with the hypothesis that multi-infrastructure failures triggered by burst water mains are more common in sandy soils. When water mains in sandy soils burst, pressurised water can create subsurface voids and abrasive slurries, contributing to further infrastructure failures. Three spatial data investigations, at nested scales, were used to assess the influence that soil sand content has on the frequency and damage caused by burst water mains (1) to roads in the county of Lincolnshire, (2) to other proximal water mains in East Anglia and (3) to other proximal infrastructure and wider society across England and Wales. These investigations used infrastructure network and failure data, media reports and soil maps, and were supported by workshop discussions and structured interviews with infrastructure industry experts. The workshop, interviews and media reports produced a greater depth of information on the infrastructure and societal impacts of cascading failures than the analysis of infrastructure data. Cross-infrastructure impacts were most common on roads, built structures and gas pipes, and they occurred at a higher rate in soils with very high sand contents.Item Open Access The influence of soil on the impacts of burst water mains on infrastructure and society: A mixed methods investigation(European Geosciences Union (EGU) / Copernicus Publications, 2017-12-12) Farewell, Timothy S.; Jude, Simon; Pritchard, Oliver G.Society relies on infrastructure, but colocation and interdependencies make infrastructure systems vulnerable to cascading failures. This study investigated cross-infrastructure and societal impacts of burst water mains, with the hypotheses that (1) burst main-triggered cross-infrastructure failures are more common in sandy soils and (2) mixed-methods approaches are more beneficial than pure data analysis for understanding the wide-ranging impacts of these events. When water mains in sandy soils burst, pressurised water can create sub-surface voids and abrasive slurries, contributing to further infrastructure failures. To investigate the role of soil in hosting cascading infrastructure failures, maps of soil sand content for England and Wales were created. Analysis of the infrastructure impacts arising from burst mains combined; (1) spatio-temporal clustering and analysis of infrastructure failure data, (2) meta-analysis of web-based media reports of burst mains impacting on other networks, and (3) workshop discussions and structured interviews with infrastructure industry experts. The workshop, interviews and media reports produced a greater depth of information on the infrastructure and societal impacts of cascading failures than the spatio-temporal data analysis. Cross infrastructure impacts were most common on roads, built structures and gas pipes, and occurred at a higher rate in soils with very high sand contents.Item Open Access Probabilistic soil moisture projections to assess Great Britain's future clay-related subsidence hazard(Springer, 2015-09-05) Pritchard, Oliver G.; Hallett, Stephen H.; Farewell, Timothy S.Clay-related subsidence is Great Britain’s (GB) most damaging soil-related geohazard, costing the economy up to £500 million per annum. Soil-related geohazard models based on mineralogy and potential soil moisture deficit (PSMD) derived from historic weather data have been used in risk management since the 1990s. United Kingdom Climate Projections (UKCP09) suggest that regions of GB will experience hotter, drier summers and warmer, wetter winters through to 2050. As a result, PSMD fluctuations are expected to increase, exacerbating the shrinkage and swelling of clay soils. A forward-looking approach is now required to mitigate the impacts of future climate on GB’s built environment. We present a framework for incorporating probabilistic projections of PSMD, derived from a version of the UKCP09 stochastic weather generator, into a clay subsidence model. This provides a novel, national-scale thematic model of the likelihood of clay-related subsidence, related to the top 1-1.5m soil layer, for three time periods; baseline (1961-1990), 2030 (2020-2049) and 2050 (2040-2069). Results indicate that much of GB, with the exception of upland areas, will witness significantly higher PSMDs through to the 2050’s. As a result, areas with swelling clay soils will be subject to proportionately increased subsidence hazard. South-east England will likely incur the highest hazard exposure to clay-related subsidence through to 2050. Potential impacts include increased incidence of property foundation subsidence, alongside deterioration and increased failure rates of GB’s infrastructure networks. Future clay-subsidence hazard scenarios provide benefit to many sectors, including: finance, central and local government, residential property markets, utilities and infrastructure operators.Item Open Access Soil geohazard mapping for improved asset management of UK local roads(Copernicus Publications, 2015-05-08) Pritchard, Oliver G.; Hallett, Stephen H.; Farewell, Timothy S.Unclassified roads comprise 60% of the road network in the United Kingdom (UK). The resilience of this locally important network is declining. It is considered by the Institution of Civil Engineers to be “at risk” and is ranked 26th in the world. Many factors contribute to the degradation and ultimate failure of particular road sections. However, several UK local authorities have identified that in drought conditions, road sections founded upon shrink–swell susceptible clay soils undergo significant deterioration compared with sections on non-susceptible soils. This arises from the local road network having little, if any, structural foundations. Consequently, droughts in East Anglia have resulted in millions of pounds of damage, leading authorities to seek emergency governmental funding. This paper assesses the use of soil-related geohazard assessments in providing soil-informed maintenance strategies for the asset management of the locally important road network of the UK. A case study draws upon the UK administrative county of Lincolnshire, where road assessment data have been analysed against mapped clay-subsidence risk. This reveals a statistically significant relationship between road condition and susceptible clay soils. Furthermore, incorporation of UKCP09 future climate projections within the geohazard models has highlighted roads likely to be at future risk of clay-related subsidence.Item Open Access Soil impacts on UK infrastructure: current and future climate(Institution of Civil Engineers, 2014-08-01) Pritchard, Oliver G.; Hallett, Stephen H.; Farewell, TimothyThis paper undertakes a critical review of the literature concerning mechanisms and impacts of soil-related geohazards to UK infrastructure. The country is predicted to have drier, hotter summers and wetter, warmer winters that in turn will increase the magnitude and frequency of many soil-related geohazards – predominantly due to changes in soil moisture. Probabilistic assessment will be required given the inherent uncertainty in assessing chronic soil hazards. The aim of this paper is to recommend a national framework methodology to aid the management of future risks posed by soil geohazards to UK infrastructure. The framework will help to prioritise ground investigations in high-risk areas, help to design suitable mitigation measures and encapsulate expert knowledge to interpret risk.Item Open Access Soil-related geohazard assessment for climate-resilient UK infrastructure(Cranfield University, 2015-11) Pritchard, Oliver G.; Hallett, Stephen; Farewell, TimothyUK (United Kingdom) infrastructure networks are fundamental for maintaining societal and economic wellbeing. With infrastructure assets predominantly founded in the soil layer (< 1.5m below ground level) they are subject to a range of soil-related geohazards. A literature review identified that geohazards including, clay-related subsidence, sand erosion and soil corrosivity have exerted significant impacts on UK infrastructure to date; often resulting in both long-term degradation and ultimately structural failure of particular assets. Climate change projections suggest that these geohazards, which are themselves driven by antecedent weather conditions, are likely to increase in magnitude and frequency for certain areas of the UK through the 21st century. Despite this, the incorporation of climate data into geohazard models has seldom been undertaken and never on a national scale for the UK. Furthermore, geohazard risk assessment in UK infrastructure planning policy is fragmented and knowledge is often lacking due to the complexity of modelling chronic hazards in comparison to acute phenomenon such as flooding. With HM Government's recent announcement of £50 million planned infrastructure investment and capital projects, the place of climate resilient infrastructure is increasingly pertinent. The aim of this thesis is therefore to establish whether soil-related geohazard assessments have a role in ensuring climate-resilient UK infrastructure. Soil moisture projections were calculated using probabilistic weather variables derived from a high-resolution version of the UKCP09 (UK Climate Projections2009) weather generator. These were then incorporated into a geohazard model to predict Great Britain's (GB) subsidence hazard for the future scenarios of 2030 (2020-2049) and 2050 (2040-2069) as well as the existing climatic baseline (1961-1990). Results suggest that GB is likely to be subject to increased clay-related subsidence in future, particularly in the south east of England. This thesis has added to scientific understanding through the creation of a novel, national-scale assessment of clay subsidence risk, with future assessments undertaken to 2050. This has been used to help create a soil- informed maintenance strategy for improving the climate resilience of UK local roads, based on an extended case study utilising road condition data for the county of Lincolnshire, UK. Finally, a methodological framework has been created, providing a range of infrastructure climate adaptation stakeholders with a method for incorporating geohazard assessments, informed by climate change projections, into asset management planning and design of new infrastructure. This research also highlights how infrastructure networks are becoming increasingly interconnected, particularly geographically, and therefore even minor environmental shocks arising from soil-related geohazards can cause significant cascading failures of multiple infrastructure networks. A local infrastructure hotspot analysis methodology and case-study is provided.