Probabilistic soil moisture projections to assess Great Britain's future clay-related subsidence hazard

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.EPSR

Soil geohazard mapping for improved asset management of UK local roads

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

Enhanced visualization of the flat landscape of the Cambridgeshire Fenlands

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

Mathematical modelling in the response to the HIV/AIDS epidemic in southern Africa

Imperial Users onl

Forward-looking climatic scenarios of UK clay-related subsidence risk

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

Coastal risk adaptation: the potential role of accessible geospatial Big Data

Increasing numbers of people are living in and using coastal areas. Combined with the presence of pervasive coastal threats, such as flooding and erosion, this is having widespread impacts on coastal populations, infrastructure and ecosystems. For the right adaptive strategies to be adopted, and planning decisions to be made, rigorous evaluation of the available options is required. This evaluation hinges on the availability and use of suitable datasets. For knowledge to be derived from coastal datasets, such data needs to be combined and analysed in an effective manner. This paper reviews a wide range of literature relating to data-driven approaches to coastal risk evaluation, revealing how limitations have been imposed on many of these methods, due to restrictions in computing power and access to data. The rapidly emerging field of ‘Big Data’ can help overcome many of these hurdles. ‘Big Data’ involves powerful computer infrastructures, enabling storage, processing and real-time analysis of large volumes and varieties of data, in a fast and reliable manner. Through consideration of examples of how ‘Big Data’ technologies are being applied to fields related to coastal risk, it becomes apparent that geospatial Big Data solutions hold clear potential to improve the process of risk based decision making on the coast. ‘Big Data’ does not provide a stand-alone solution to the issues and gaps outlined in this paper, yet these technological methods hold the potential to optimise data-driven approaches, enabling robust risk profiles to be generated for coastal regions

Estimating the risk of HIV transmission from homosexual men receiving treatment to their HIV-uninfected partners

Objective To determine how the risk of HIV transmission from homosexual men receiving antiretroviral treatment is related to patterns of patient monitoring and condom use. Methods A stochastic mathematical simulation model was developed of cohorts of men in the Netherlands who have sex with men (MSM), defining the parameters of the model using observational cohort data. The model incorporates viral load trends during first-line treatment, patient monitoring and different scenarios for the way in which condom use may depend on recent viral load measurements. The model does not include the effect of sexually transmitted infections on HIV transmission. Results For MSM receiving treatment, the risk of transmitting HIV to their long-term partner is 22% (uncertainty interval: 9-37%) if condoms are never used. With incomplete use (in 30% of sex acts) the risk is reduced slightly, to 17% (7-29%). However, the risk is as low as 3% (0.2-8%) when men receiving treatment use condoms only 6 months beyond their last undetectable viral load measurement. The risk is further reduced when 3 months is the time period beyond which condoms are used. Conclusions When condom use by HIV-infected men receiving combination treatment with antiretroviral agents is based on their last viral load measurement, the transmission risk is much lower than with incomplete condom use. The key message for patients is that although always using condoms during treatment is the best way to protect partners from the risk of HIV transmission, when such use cannot be achieved, the second best strategy is to use condoms whenever the last undetectable viral load was measured more than 3 months ag

Setting research priorities in Global Health : appraising the value of evidence generation activities to support decision-making in health care

The allocation of scarce resources among competing health care priorities is a key objective in all jurisdictions, whether in low- and middle-income countries (LMICs) or high-income countries. This involves allocating resources to ensure access to health care programmes, which can deliver improvements in health, but also to managing innovation in the development of new technologies, and investing in evidence generation activities to improve health for future generations. The allocation of health care resources among competing priorities requires an assessment of the expected health effects and costs of investing resources in the different activities and the opportunity costs of these expenditures, as well as an assessment of the uncertainty in health effects and costs. Uncertainty can lead to unintended adverse health consequences, e.g., when expected benefits of an activity are not realised when implemented in practice, or resources committed by an activity are transferred away from other health improving activities. The consequences of uncertainty can be reduced by investing in evidence generation activities that improve the information available to support future resource allocation decisions. An analytic framework is developed to assess the value of evidence generation activities to support international research funders, who have the responsibility for allocating funds among competing research priorities in Global Health. Within the framework, the costs and health benefits of evidence generation activities are assessed using the same principles as those employed when evaluating the cost-effectiveness of investments in service provision. Metrics of value, founded on an understanding of the health opportunity costs imposed by research expenditure, are used to quantify the scale of the potential global net health impact across all beneficiary populations (in net disability-adjusted life years averted), or the equivalent health care system resources required to deliver this net health impact, and research costs and their potential health opportunity costs. The framework can be applied to answer key questions such as: whether investment in research activities is worthwhile; which research activities should be prioritised; what type of research activity is necessary and what is the most appropriate design of the research; what are the opportunity costs associated with evidence generation; what is the optimal timing of research; and whether evidence generation activities should be prioritised over investments in service provision or new technology development. An illustrative example is used to demonstrate the application of the framework for informing research priorities in Global Health

Do risk, time and prosocial preferences predict risky sexual behaviour of youths in a low-income, high-risk setting?

Young people in sub-Saharan Africa are particularly at high risk of sexually transmitted infections. Little is known about their preferences and even less about their association with risky sexual behaviour. We conducted incentivized economic experiments to measure risk, time and prosocial preferences in Zimbabwe. Preferences measured at baseline predict biomarker and self-reported measures of risky sexual behaviour gathered 12 months later. We find robust evidence that individuals more altruistic at baseline are more likely to be Herpes Simplex Virus Type-2 (HSV-2) positive 12 months later. Analysis by sex shows this association is driven by our sample of women. Having more sexual partners is associated with greater risk tolerance amongst men and greater impatience amongst women. Results highlight heterogeneity in the association between preferences and risky sexual behaviour