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Petra Tschakert Regina Sagoe Gifty Ofori-Darko Samuel Nii Codjoe 《Climatic change》2010,103(3-4):471-502
This study explores the implications of recent extreme rainfall and flood events in the Sahel and the wider West African region for climate change adaptation. Are these events merely a temporal nuisance as suggested by the lingering desertification discourse or will more climatic extremes characterize the region over the next century? After reviewing incidences of severe rainfall and projected future climate variability, the paper examines local flood knowledge and decision-making, drawing upon a case study in Ghana. The data demonstrate that a variety of response strategies to flooding exist; yet, knowledge of and access to climate forecasts and other learning tools are essentially absent. So far, floods have not triggered mass displacement although cumulative environmental deterioration is likely to cause environmental refugees. The paper recommends to lay to rest the desertification narrative, consider the possibility of both floods and droughts, and mobilize local memory for anticipatory learning and practical adaptation. 相似文献
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Synthesis of Environmental Impacts of Deep Seabed Mining 总被引：1，自引：0，他引：1
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George Owusu Edward Nketiah-Amponsah Samuel Nii Ardey Codjoe Robert L. Afutu-Kotey 《Urban geography》2013,34(8):1140-1155
Like many countries in sub-Saharan Africa, Ghana lacks well-engineered sanitary landfill sites. Increased urbanization and concomitant real estate growth lead landfills to compete with residential land use, resulting in closer proximity between landfill sites and residential neighborhoods. The effects of landfills on the property values of nearby residential communities have been the subject of much debate in the developed world, where state-of-the-art and environmentally well-engineered landfills are common. However, academic and other research is inconclusive on the effects of landfills on property values in the developed countries. This paper addresses this knowledge gap by exploring the effects of landfills on residential property values in Ghana, using the Oblogo and Mallam landfills in Accra as a case study. Our analysis indicates that while landfills do depress nearby residential property values, the effects are contingent on property location relative to the level of urbanization in a community, and year of completion and total costs of property development. 相似文献
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Although sub-Saharan Africa does not contribute significantly to greenhouse gas emissions, significant adverse impacts of climate change are anticipated in this region. Countries in West Africa, which are heavily dependent on rain-fed agriculture, are projected to experience more frequent and intense droughts, altered rainfall patterns and increases in temperature through the end of this century. Changes in hydrology and temperature are likely to affect crop yields, thereby placing pressure on scarce resources in a region that is characterised by limited social, political, technical and financial resources. The success with which communities cope with the impacts of climate change is influenced by existing conditions, forces and characteristics which are peculiar to each of these communities. This paper assesses the preferred adaptation strategies during floods and droughts of males and females in three different occupations (farming, fishing, and charcoal production). Findings are based upon an analysis of focus group discussions and a ranking of preferred adaptation options in three communities in the Afram Plains of Ghana. Assessments of this nature should aid in the selection and implementation of adaptation options for communities and households, which is the level at which climate change adaptation is likely to occur in West Africa. 相似文献
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Cyclic soil degradation and hardening affects soil stiffness and strength, and is linked to an increase or decrease in the
mean effective confining stress due to void ratio or pore pressure changes. This change of state can be explicitly modeled
by using effective stress methods, or implicitly modeled using total stress methods. In the latter, this is achieved by using
empirical functions based on the number of loading cycles that are derived from constant-amplitude stress or strain laboratory
tests. To suite generalized loading conditions, these functions must be extrapolated to variable-amplitude loading. This falls
under the general class of a fatigue-based problem. The main focus of this paper is to present a generalized consistent soil
fatigue formulation for soils under cyclic loading. The paper then goes on to discuss the implementation of various cyclic
soil degradation and hardening models reported in the literature, and highlights their important underlying assumptions, capabilities
and limitations. 相似文献
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The response of shallow foundations under lateral cyclic loading is generally nonlinear and involves rocking, sliding, settlement, and may also involve foundation uplift and soil yielding. Unlike pile foundations, the nonlinear Winkler model is not widely used for modeling cyclic soil–footing–structure interaction (SFSI) problems. Nonetheless, it has some important features that make it more attractive than conventional finite element approaches, and is a recommended approach in the FEMA 356 design guideline. This paper explores the strengths and limitations of the FEMA 356 nonlinear Winkler modeling approach, when used in predicting the cyclic response of various recent SFSI experiments. The results of the study show that the model is capable of satisfactorily predicting all the different cyclic response quantities apart from permanent horizontal displacements. This should therefore be noted when using the approach in design. 相似文献
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Trepekli Katerina Balstrøm Thomas Friborg Thomas Fog Bjarne Allotey Albert N. Kofie Richard Y. Møller-Jensen Lasse 《Natural Hazards》2022,113(1):423-451
Natural Hazards - In this study, we present the first findings of the potential utility of miniaturized light and detection ranging (LiDAR) scanners mounted on unmanned aerial vehicles (UAVs) for... 相似文献
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Analytical equations for the moment–rotation response of a rigid foundation on a Winkler soil model are presented. An equation is derived for the uplift-yield condition and is combined with equations for uplift- and yield-only conditions to enable the definition of the entire static moment–rotation response. The results obtained from the developed model show that the inverse of the factor of safety, χ, has a significant effect on the moment–rotation curve. The value of χ=0.5 not only determines whether uplift or yield occurs first but also defines the condition of the maximum moment–rotation response of the footing. A Winkler model is developed based on the derived equations and is used to analyze the TRISEE experiments. The computed moment–rotation response agrees well with the experimental results when the subgrade modulus is estimated using the unload–reload stiffness from static plate load–deformation tests. A comparison with the recommended NEHRP guidelines based on the FEMA 273/274 documents shows that the choice of value of the effective shear modulus significantly affected the comparison. 相似文献