76 research outputs found
Characterising the vulnerability of fishing households to climate and environmental change: Insights from Ghana
Rural coastal communities in the global south are mostly natural resource-dependent and their livelihoods are therefore vulnerable to the impacts of climate and environmental changes. Efforts to improve their adaptive capacity often prove mal-adaptive due to misunderstanding the dynamics of the unique socioeconomic factors that shape their vulnerability. By integrating theories from climate change vulnerability and the Sustainable Livelihoods Approach, this study draws upon household survey data from a fishing community in Ghana to assess the vulnerability of fishing households to climate change and explore how their vulnerability is differentiated within the community. The findings suggest that household incomes in the last decade have reduced significantly, attributable to an interaction of both climatic and non-climatic factors. Analysis of the characteristics of three vulnerability groups derived by quantile clustering showed that the most vulnerable household group is not necessarily women or poorer households as expected. Rather, it is dynamic and includes all gender and economic class categories in varying proportions depending on the success or failure of the fishing season. The findings suggest furthermore that the factors that significantly differentiates vulnerability between households differ, depending on whether households are categorised by economic class, gender of household-head or vulnerability group. Consequently, the study highlights the importance of looking beyond existing social categorizations like gender and economic classes when identifying and prioritizing households for climate change adaptive capacity building
Climate change impact and adaptation: Lagoonal fishing communities in west Africa
Lagoons are a common feature of the low-lying West African coastline. These lagoons are resource-rich and biodiverse. The small-scale fishing communities, which border them, are dependent on the resources and ecosystem services for their livelihoods and well-being. Climate change has had significant and diverse effects on both the lagoons and their surrounding communities. Sea level rise has caused erosion of the coast and increased the risk of floods. Changes to rainfall patterns have caused shifts in lagoon ecosystems and physical cycles. Of particular relevance to lagoon fishing communities is the fluctuation in quantity and distribution of fish catch that they rely upon for economic livelihood. Understanding the vulnerability of these communities to the effects of climate change is critical to supporting and developing successful adaptations. Using a case study from Ghana, sustainable livelihoods approach (SLA) and vulnerability framework are used to characterize the community vulnerability, giving insight into the temporal and spatial dynamics of vulnerability and how subsections of the community may be identified and prioritized for adaptation interventions. A scalar analysis of the relevant coastal and environmental frameworks and policy to support climate change adaptation in coastal communities reveals the common challenges in implementing adaptation interventions and strategies in the region. A policy gap exists between high level, institutional coastal, and climate directives and implementation of climate adaptations at the local level. That gap might be bridged by a participatory approach that places coastal communities at the center of creating and enacting climate change adaptations
Experimental investigations of bolted segmental grey cast iron lining behaviour
The need for the research reported in this paper was driven by the Crossrail project in London for which new tunnels were constructed close to numerous existing operational tunnels of the London Underground (LU) network. This research is based on experimental work conducted on half-scale grey cast iron (GCI) tunnel lining segments with chemical composition similar to the Victorian age GCI segments in the LU network. This paper discusses the deformation behaviour of the bolted segmental lining under the influence of factors such as overburden pressure, bolt preload and presence of grommets at small distortions. The measured behaviour of the segmental lining is compared against the calculated response of a continuous lining based on the assumption of elasticity. The industry practice for tunnel lining assessment is to calculate the induced bending moment in the tunnel lining using an elastic continuum model, while adopting a reduced lining stiffness to take into account the presence of the joints. Case studies have recorded that both loosening and tightening of lining bolts have been used as mitigation measures to reduce the impact of new tunnel excavations on existing GCI tunnels. The experimental work on the half-scale GCI lining has shown that a bolted segmental lining behaves as a continuous ring under small distortions imposed when subjected to hoop forces relevant to the depth of burial of LU tunnels. In the presence of hoop force, joint opening was minimal and the magnitude of preload in the bolts had little impact on the behaviour of the lining. It is therefore concluded that disturbance of the bolts in existing tunnels is not recommended as a mitigation measure as in addition to being ineffective it is both time consuming and introduces the risk of damaging the tunnel lining flanges
Geology of Caphouse Colliery, Wakefield, Yorkshire, UK
The National Coal Mining Museum in West Yorkshire affords a rare opportunity for the public to visit a former colliery (Caphouse) and experience at first hand the geology of a mine. The geology at the museum can be seen via the public tour, limited surface outcrop and an inclined ventilation drift, which provides the best geological exposure and information. The strata encountered at the site are c. 100 m thick and are of latest Langsettian (Pennsylvanian) age. The ventilation drift intersects several coal seams (Flockton Thick, Flockton Thin, Old Hards, Green Lane and New Hards) and their associated roof rocks and seatearths. In addition to exposures of bedrock, recent mineral precipitates of calcium carbonates, manganese carbonates and oxides, and iron oxyhydroxides can be observed along the drift, and there is a surface exposure of Flockton Thick Coal and overlying roof strata. The coals and interbedded strata were deposited in the Pennine Basin in a fluvio-lacustrine setting in an embayment distant from the open ocean with limited marine influence. A lacustrine origin for mudstone roof rocks of several of the seams is supported by the incidence of non-marine bivalves and fossilized fish remains whilst the upper part of the Flockton Thick Coal consists of subaqueously deposited cannel coal. The mudstones overlying the Flockton Thick containing abundant non-marine bivalves are of great lateral extent, indicating a basin-wide rise of base level following coal deposition that may be compared with a non-marine flooding surface
Derivation of shear enhancement factor β used in FprEN1992 to calculate design shear force at corner columns of flat slabs
The next generation of Eurocode 2 (FprEN 1992) adopts a closed form version of the Critical Shear Crack Theory (CSCT) for punching shear design. The code accounts for loading eccentricity by multiplying the design shear force by a coefficient β. The paper describes the derivation of the expression adopted in FprEN 1992 for β at corner columns of flat slabs. The proposed formula is validated for normal size columns, with maximum side length less than 3d, where d is the slab mean effective depth, and non-square columns with long side greater than 3d. Due to the absence of experimental data on punching resistance at non-square corner columns, the derived formula is validated for such columns using NLFEA with 3-D solid elements. Comparisons are also made with punching resistances determined using the classic CSCT in which punching resistance is explicitly related to slab rotation relative to the support. The closed form CSCT is shown to predict punching shear resistance well, when used in conjunction with the proposed β factor
Virtual mobility to enhance intercultural competencies for a more sustainable future
The UN locates education at the heart of the process to achieve a more sustainable future and deliver the 17 Sustainable Development Goals (UN-SDGs) by 2030. Within this context, this paper outlines the experience of designing and delivering an international virtual mobility workshop which brought together university students from the UK and Ghana. It offers a critical evaluation of the extent to which the workshop's objectives were achieved, through comparison of pre- and post-workshop survey results, with a particular emphasis on changing levels of understanding of the UN-SDGs and the development of key intercultural competencies. The discussion highlights positive trajectories of change in student learning, and the challenges of delivering workshops of this nature. It is concluded that such challenges can be embraced as learning opportunities and that the associated discomfort and uncertainty is important to facilitate impactful learning experiences
Influence of beam cross-section, loading arrangement and aggregate type on shear strength
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