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

Investigating the effect of tunnelling on existing tunnels

A major research project investigating the effect of tunnelling on existing tunnels has been completed at Imperial College London. This subject is always of great concern during the planning and execution of underground tunnelling works in the urban environment. Many cities already have extensive existing tunnel networks and so it is necessary to construct new tunnels at a level beneath them. The associated deformations that take place during tunnelling have to be carefully assessed and their impact on the existing tunnels estimated. Of particular concern is the serviceability of tunnels used for underground trains where the kinematic envelope must not be impinged upon. The new Crossrail transport line under construction in London passes beneath numerous tunnels including a number of those forming part of the London Underground networ

Repairing a shield tunnel damaged by secondary grouting.

This paper reports on a repair work which has recently been conducted for a metro tunnel in Hefei city, China. The tunnel has been originally constructed using shield method where synchronous grouting was used to fill the gaps between the tunnel segments and soil. Following a regular maintenance inspection of the tunnel, several leakage issues were identified between three stations. Secondary grouting was adopted as a solution to block the tunnel leakage, however, shortly after the start of grouting work, the track and track bed were found to be unevenly uplifted with significant cracks in the tunnel’s segments. The paper describes and discusses key aspects of this case study including ground conditions, leakages patterns of the tunnel, recorded volumes and injection pressure of the secondary grouting, as well as survey data of track displacement and segment cracks. The investigation confirmed that the situation was caused by an inappropriate implementation of the secondary grouting, particularly by high grouting pressure (significantly higher than the geostatic pressure), large volumes of injected grout, and poor selection of grouting locations. Ground Penetrating Radar (GPR) was conducted to inspect the tunnel conditions before commencing the structural repair work, which revealed that there were no voids under the track bed of the affected zone. The study presents simplified strategies used to repair the damage while maintaining minimum disturbance to the affected segments

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

Ultimate capacity of a segmental grey cast iron tunnel lining ring subjected to large deformations

Understanding the behaviour of existing tunnels subjected to in-service deformations, as a result of the construction of underground works (e.g. new tunnels) in their proximity, is of importance in order to safeguard infrastructure within the urban environment. The associated deformations that take place during tunnelling have to be carefully assessed and their impact on the existing tunnels needs to be considered. A half-scale segmental grey cast iron (GCI) tunnel lining ring was tested as part of an extensive research project investigating the impact of new tunnel excavations on existing tunnels conducted at Imperial College London. A sophisticated experimental arrangement was developed to deform the ring in a variety of modes under combined displacement and load control. This paper reports on experiments carried out to assess its structural response when subjected to large deformations. The tests reported are the first to be conducted on a realistic scale model under carefully controlled conditions, and provide valuable insight into the behaviour of a GCI segmental ring during distortions commonly observed in reality. Details of the experiments, including the adopted test set-up and the instrumentation employed, are presented. The measured bending moments around the ring, as a result of the applied deformations, are determined and compared with those predicted using the well-known equations given by Morgan (1961) and Muir Wood (1975), often used in industry, as well as those obtained assuming an elastic continuous ring.The authors would like to thank the EPSRC (Grant number EP/G063486/1), Crossrail Ltd, and Morgan Sindall for funding this research project and London Underground for providing extensive assistance. In particular, thank you to Mr. Mike Black, Dr. Keith Bowers, Mr. Colin Eddie, Mr. David Harris, Mr. Neil Moss, Dr. Barry New, Mr. Sotiris Psomas, and Mr. Peter Wright. The authors must also thank Imperial College research technicians Mr. Duncan Parker, Mr. Steve Ackerley and Mr. Leslie Clark

Predicting violent infractions in a Swiss state penitentiary: A replication study of the PCL-R in a population of sex and violent offenders

BACKGROUND: Research conducted with forensic psychiatric patients found moderate correlations between violence in institutions and psychopathy. It is unclear though, whether the PCL-R is an accurate instrument for predicting aggressive behavior in prisons. Results seem to indicate that the instrument is better suited for predicting verbal rather than physical aggression of prison inmates. METHODS: PCL-R scores were assessed for a sample of 113 imprisoned sex and violent offenders in Switzerland. Logistic regression analyses were used to estimate physical and verbal aggression as a function of the PCL-R sum score. Additionally, stratified analyses were conducted for Factor 1 and 2. Infractions were analyzed as to their motives and consequences. RESULTS: The mean score of the PCL-R was 12 points. Neither the relationship between physical aggression and the sum score of the PCL-R, nor the relationship between physical aggression and either of the two factors of the PCL-R were significant. Both the sum score and Factor 1 predicted the occurrence of verbal aggression (AUC=0.70 and 0.69), while Factor 2 did not. CONCLUSION: Possible explanations are discussed for the weak relationship between PCL-R scores and physically aggressive behavior during imprisonment. Some authors have discussed whether the low base rate of violent infractions can be considered an explanation for the non-significant relation between PCL-R-score and violence. The base rate in this study, however, with 27%, was not low. It is proposed that the distinction between reactive and instrumental motives of institutional violence must be considered when examining the usefulness of the PCL-R in predicting in-prison physical aggressive behavior

Shoreline change and sea level rise at the Muni-Pomadze coastal wetland (Ramsar site), Ghana

Lagoon-wetland systems are common along low-lying coastlines. They provide rich species habitats, multiple ecosystem services and socio-economic activities. They are particularly susceptible to the impacts of sea level rise (SLR), especially in less developed countries (LDCs) where economic and development constraints limit adaptation. The Muni-Pomadze lagoon is one of five coastal Ramsar sites in Ghana and one of many along the country’s coastline. It is an intermittently closed lagoon with extreme seasonal hydrological and physico-chemical variation. Field observation, digital mapping and GIS analysis of the shoreline has enabled an understanding of coastal change and SLR at the lagoon. From 1972 to 2014 the high water mark has shifted landwards with an average retreat rate of 0.22 m/year. Evidence of erosion and sediment washover indicate loss of and a shift landward of the sand barrier separating the lagoon from the ocean. Creation of an inundation map for a one-meter rise of sea level reveals fragementation and breaching of the barrier and an increasingly permanent connection to the ocean. A more open lagoon system stabilises hydrological and physico-chemical conditions, leading to increases in biodiversity and aquatic productivity. The lagoon currently has no consideration of SLR in its management plan. The results of this analysis and the limited development of the Muni-Pomadze lagoon support a no intervention approach to coastal management that allows SLR to transform the closed lagoon to an open estuary. A similar approach at comparable coastal wetland systems in Ghana and in other LDCs could prove an effective management option

New network aims to sustain vital lagoons

Lagoons are the unsung hero of coastal environments. Common along low-lying coastlines around the world, these fragile aquatic environments delicately balance marine and terrestrial systems and cycles. They occur on the landward side of beach barriers and have varying connectivity to the open ocean. Some are rarely connected to the sea, confined behind sandy barriers and deriving most of their water from land, while others have connections or inlets that allow the free flow of seawater. Lagoons support high levels of biodiversity and are one of the most productive ecosystems on earth. Many are the sites of critical wetlands that act as natural carbon sinks. They also provide an abundance of other ecosystem services that cross ecological, social, cultural and economic boundaries