On the basis of Terzaghi's one-dimensional consolidation theory, the variation of effective stress ratio in layered saturated soils with impeded boundaries under time-dependent loading was studied. By the method o...On the basis of Terzaghi's one-dimensional consolidation theory, the variation of effective stress ratio in layered saturated soils with impeded boundaries under time-dependent loading was studied. By the method of Laplace transform, the solution was presented. Influences of different kinds of cyclic loadings and impeded boundaries conditions were discussed. Through numerical inversion of Laplace transform, useful illustrations were given considering several common time-dependent loadings. Pervious or impervious boundary condition is just the special case of the problem considered here. Compared with average index method,the results from the method illustrated are more accurate.展开更多
This paper examined the prioritized climate-smart agricultural practices by smallholder farmers,the motivations of adopting climate-smart agricultural practices,the enablers to the successful adoption of climate-smart...This paper examined the prioritized climate-smart agricultural practices by smallholder farmers,the motivations of adopting climate-smart agricultural practices,the enablers to the successful adoption of climate-smart agricultural practices,and the barriers to the successful adoption of climate-smart agricultural practices in the transitional and savannah agroecological zones of Ghana.Specifically,we employed ethnographic research using participatory approaches,including two stakeholder workshops and household surveys with 1061 households in the transitional and savannah agroecological zones of Ghana.The weighted average index(WAI)and problem confrontation index(PCI)were used to rank smallholder farmers’perceived enablers to the adoption of climate-smart agricultural practices and the barriers affecting climate-smart agricultural practices,respectively.Results suggest that the majority of the respondents used a suite of climate-smart agricultural practices,including the timely harvesting of produce and storage,emergency seed banking,appropriate and timely weed and pest control,and early planting as practices to build climate resilience.The majority of smallholder farmers primarily employed climate-smart agricultural practices to improve household food security(96.2%),reduce pests and diseases(95.6%),and obtain higher yields and greater farm income(93.2%).Findings also show that secured land tenure system arrangement,understanding the effects of climate change,and access to sustainable agricultural technologies were ranked the first,second,and third most important enablers to the adoption of climate-smart agricultural practices with the WAI values of 2.86,2.75,and 2.70,respectively.Key barriers to the successful adoption of climate-smart agricultural practices included incidences of pests and diseases(PCI=2530),inadequate access to agricultural credit(PCI=2502),high cost of improved crop varieties(PCI=2334),and limited government support with farm inputs(PCI=2296).Smallholder farmers need to be better supported through the provision of appropriate institutional and policy arrangements together with improved land management extension advice to overcome these barriers and facilitate the more effective implementation of climate-smart agricultural practices in Ghana.展开更多
文摘On the basis of Terzaghi's one-dimensional consolidation theory, the variation of effective stress ratio in layered saturated soils with impeded boundaries under time-dependent loading was studied. By the method of Laplace transform, the solution was presented. Influences of different kinds of cyclic loadings and impeded boundaries conditions were discussed. Through numerical inversion of Laplace transform, useful illustrations were given considering several common time-dependent loadings. Pervious or impervious boundary condition is just the special case of the problem considered here. Compared with average index method,the results from the method illustrated are more accurate.
基金the Future Leaders-African Independent Research(FLAIR)Fellowships funded by the Royal Society,London(FLR\R1\201640).
文摘This paper examined the prioritized climate-smart agricultural practices by smallholder farmers,the motivations of adopting climate-smart agricultural practices,the enablers to the successful adoption of climate-smart agricultural practices,and the barriers to the successful adoption of climate-smart agricultural practices in the transitional and savannah agroecological zones of Ghana.Specifically,we employed ethnographic research using participatory approaches,including two stakeholder workshops and household surveys with 1061 households in the transitional and savannah agroecological zones of Ghana.The weighted average index(WAI)and problem confrontation index(PCI)were used to rank smallholder farmers’perceived enablers to the adoption of climate-smart agricultural practices and the barriers affecting climate-smart agricultural practices,respectively.Results suggest that the majority of the respondents used a suite of climate-smart agricultural practices,including the timely harvesting of produce and storage,emergency seed banking,appropriate and timely weed and pest control,and early planting as practices to build climate resilience.The majority of smallholder farmers primarily employed climate-smart agricultural practices to improve household food security(96.2%),reduce pests and diseases(95.6%),and obtain higher yields and greater farm income(93.2%).Findings also show that secured land tenure system arrangement,understanding the effects of climate change,and access to sustainable agricultural technologies were ranked the first,second,and third most important enablers to the adoption of climate-smart agricultural practices with the WAI values of 2.86,2.75,and 2.70,respectively.Key barriers to the successful adoption of climate-smart agricultural practices included incidences of pests and diseases(PCI=2530),inadequate access to agricultural credit(PCI=2502),high cost of improved crop varieties(PCI=2334),and limited government support with farm inputs(PCI=2296).Smallholder farmers need to be better supported through the provision of appropriate institutional and policy arrangements together with improved land management extension advice to overcome these barriers and facilitate the more effective implementation of climate-smart agricultural practices in Ghana.