The afforestation of upland areas in the UK has been the largest rural land use change this century. As a consequence of afforestation the bed load yields of upland catchments have been shown to increase substantially. The upland catchment bed load is transported downstream, through the transfer zone to the lowland reaches where it may enter storage in barforms, cause flow diversion and cause channel instability. This study investigates the Afon Trannon, a river in mid-Wales whose upland catchment was afforested between 1948 and 1978 and whose lowland channel is currently unstable. Historical rates of channel change in the lowland channel have been quantified using aerial photogrammetry in ERDAS Imagine GIS. Channel instability is shown to increase significantly between 1963 and 1976, some 15 years after upland catchment afforestation. However, upland catchment bed load yields are shown to be of low magnitude (up to an estimated maximum of6.35 t km-2 yr") and incapable of producing the high medium-term lowland channel change rates observed (up to 1.88 m yr" between 1963 and 1976). Contemporary channel DTMs constructed from field survey data have allowed the construction of a contemporary lowland channel sediment budget. Local inputs of bed load from composite bank erosion are shown to dominate in the budget and reaches of maximum instability are shown to correspond with the location of these composite banks. Additionally. flood magnitude and frequency are shown to have increased since 1988 from a maximum stage of 1.50 m between 1969 and 1988 to a maximum stage of2.23 m between 1989 and 2000. A conceptual model is presented in which the medium-term instability of the lowland Afon Trannon is suggested to be triggered by local lowland bed aggradation as a result of elevated upland catchment bed load yields and a risk assessment diagram provides advice to river engineers and fluvial geomorphologists interested in assessing the potential stability of lowland rivers whose upland catchments have been afforested.

No description available.

There is a growing global urban appetite for fresh fruit and vegetables, particularly fruit. There is a further recognised need for agri-food systems that support human health, ecological integrity and social justice (Morgan and Sonnino 2010). This thesis explores the current possibilities and challenges of regenerative agri-food systems through the case of the urban apple. With the lens of political ecology, the thesis presents a relational interpretation of the spaces, natures and relations of the urban apple through considering the practices and the guiding logic of the corporate and agro-ecological urban apple in Hackney, London. The methodological framework, informed by relational geographies, supports a situated and place-based understanding of the corporate and agro-ecological logics through attending to practices in place. The thesis draws upon a number of semi-structured interviews and participant-observation with representatives involved in the production, distribution and trading of the urban apple. As the case of Growing Communities demonstrates, citizens can be supported in practicing more healthy, ecological and just ways of growing, trading and consuming food through agro-ecological communities of practice. Currently, such communities remain politically marginalised, particularly at national government levels. A political framework that fosters physical, economic and political space for regenerative agri-food practices and systems is considered key. The city-region is recognised as a ‘space of possibility’ and ‘space of action’ (Gibson-Graham and Roelvink 2011) in the scaling-out regenerative agri-food practices and systems. This needs to be supported by multi-scalar, cross-sectoral, participatory and co-productive processes (Jennings et al. 2015; Moragues-Faus and Morgan 2015; Jégou and Bonneau 2014), prioritising space for community-led, place-based practice.

The potential impacts of climate change and environmental variability are already evident in most parts of the world, which is witnessing increasing temperature rates and prolonged flood or drought conditions that affect agriculture activities and nature-dependent livelihoods. This study was conducted in Mwanga District in the Kilimanjaro region of Tanzania to assess the nature and impacts of climate change and environmental variability on agriculture-dependent livelihoods and the adaptation strategies adopted by small-scale rural farmers. To attain its objective, the study employed a mixed methods approach in which both qualitative and quantitative techniques were used. The study shows that farmers are highly aware of their local environment and are conscious of the ways environmental changes affect their livelihoods. Farmers perceived that changes in climatic variables such as rainfall and temperature had occurred in their area over the period of three decades, and associated these changes with climate change and environmental variability. Farmers’ perceptions were confirmed by the evidence from rainfall and temperature data obtained from local and national weather stations, which showed that temperature and rainfall in the study area had become more variable over the past three decades. Farmers’ knowledge and perceptions of climate change vary depending on the location, age and gender of the respondents. The findings show that the farmers have limited understanding of the causes of climatic conditions and environmental variability, as some respondents associated climate change and environmental variability with social, cultural and religious factors. This study suggests that, despite the changing climatic conditions and environmental variability, farmers have developed and implemented a number of agriculture adaptation strategies that enable them to reduce their vulnerability to the changing conditions. The findings show that agriculture adaptation strategies employ both planned and autonomous adaptation strategies. However, the study shows that increasing drought conditions, rainfall variability, declining soil fertility and use of cheap farming technology are among the challenges that limit effective implementation of agriculture adaptation strategies. This study recommends further research on the varieties of drought-resilient crops, the development of small-scale irrigation schemes to reduce dependence on rain-fed agriculture, and the improvement of crop production in a given plot of land. In respect of the development of adaptation strategies, the study recommends the involvement of the local farmers and consideration of their knowledge and experience in the farming activities as well as the conditions of their local environment. Thus, the findings of this study may be helpful at various levels of decision making with regard to the development of climate change and environmental variability policies and strategies towards reducing farmers’ vulnerability to current and expected future changes.

Air pollution is an emotive and complex issue, affecting materials, vegetation growth and human health. Given that over half the world's population live within urban areas and that those areas are often highly polluted, the ability to understand the patterns and magnitude of pollution at the small area (urban environment) level is increasingly important. Recent research has highlighted, in particular, the apparent relationship between traffic-related pollution and respiratory health, while the increasing prevalence of asthma, especially amongst children, has been widely attributed to exposure to traffic-related air pollution. The UK government has reacted to this growing concern by publishing the UK National Air Quality Strategy (DOE 1996) which forces all Local Authorities in England and Wales to review air quality in their area and designate any areas not expected to meet the 2005 air quality standards as Air Quality Management Areas (AQMAs), though what constitutes AQMAs and how to define them remains vague. Against this background, there is a growing need to understand the patterns and magnitude of urban air pollution and for improvements in pollution mapping methods. This thesis aims to contribute to this knowledge. The background to air pollution and related research has been examined within the first section of this report. A review of sampling methods was conducted, a sampling strategy devised and a number of surveys conducted to investigate both the spatial nature of air pollution and, more specifically, the dispersion of pollution with varying characteristics (distance to road, vehicle volume, height above ground level etc). The resultant data was analysed and a number of patterns identified. The ability of linear dispersion models to accurately predict air pollution was also considered. A variety of models were examined, ranging from the simplistic (e.g. DMRB) to the more complex (e.g. CALINE4) model. The model best able to predict pollution at specific sites was then used to predict concentrations over the entire urban area which were then compared to actual monitored data. The resultant analysis, indicated that the dispersion model is not a good method for predicting pollution concentrations at the small area level, and therefore an alternative method of mapping was investigated. Using the ARC/INFO geographical information system (GIS) a regression analysis approach was applied to the study area. A number of variables including altitude, landuse type, traffic volume and composition etc, were examined and their ability to predict air pollution tested using data on nitrogen dioxide from intensive field surveys. The study area was then transformed into a grid of 10m2, regression analysis was performed on each individual square and the results mapped. The monitored data was then intersected with the resultant map and monitored and modeled concentrations compared. Results of the analysis indicated that the regression analysis could explain up to 61 per cent of the variation in nitrogen dioxide concentrations and thus performed significantly better than the dispersion model method. The ease of application and transferability of the regression method means it has a wide range of applied and academic uses that are discussed in the final section.

This thesis explores speleogenesis within the Dartry Limestone Formation of Cuilcagh Mountain by considering the hydrogeology of the aquifer in the modern setting but also by considering its evolution since it was deposited during Asbian (Dinantian) times. Due to the synclinal structure of the region, which gently plunges northwestwards, the aquifer remains buried beneath the upland and is not exposed to the south. However, the formation outcrops along its northern and eastern upland margins where resurgences drain the aquifer via an extensive network of cave systems, which include Marble Arch Cave. In the west, the aquifer lies near surface but a significant artesian resurgence, Shannon Pot Rising, emerges from the aquifer via c. 20m of overlying sandstones and shales. Water tracing experiments undertaken during this research project have added significant clarity to the hydrological regime that operates within this karst aquifer. These tests have shown that whilst extensive conduit systems are present at the eastern and northern margins of the uplands, Shannon Pot Rising in the west is the outlet for a regional conduit system that operates beneath Cuilcagh Mountain where the aquifer remains buried and in places confined. Water tracing has also identified that the boundary between the regional and marginal systems correlates to an igneous intrusion, the Cuilcagh Dyke. Hydrochemical data from Shannon Pot Rising indicates that the regional system has both shallow and deep flow components. This and hydrogeological evidence indicates that Shannon Pot developed as an overflow and that it's conduits formed at depth and unrelated to surface processes. Study of the cave systems at the eastern and northern margins have identified a number of lithological discontinuities within the sequence that have guided conduit inception within the aquifer. These early systems were later modified when the aquifer became unconfined and surface karst landforms developed.

Ethiopia's forest resource base, which is mostly found in the southwestern highlands, supports a multitude of agricultural production systems. However, similar to the trend in other parts of the developing world, deforestation has taken a heavy toll in this part of Ethiopia. Cognisant of this, recently policies and strategies have been devised that emphasise the need for citizens' participation in natural forest management. Yet, in Ethiopia there is little field-based analytical literature that throws light on the stake that villagers have in forest resources and the workings of local level forest access channels. Against this backdrop, the research examines state-community and intra-community relationships in the course of accessing forest resources under governments of widely differing political persuasions, and investigates the current importance of forests to the local household economy. This is achieved through a case study of six forest communities in a rural district of highland Kafa, southwest Ethiopia. The study employs a time line approach to trace the evolution of state-community interactions in the provision and administration of forest tenure at the local level. To this end, the research has examined the political history of Kafa and the land management policies of successive Ethiopian governments that had a bearing on local forest access and use. The broader themes of the research are informed by the literature on natural resource tenure establishment and household level forest use in agrarian systems and the discourse on management regimes in common pool resources. The research has established that throughout much of Kafa's history forests were accessed through customary tenure principles. However, following Kafa's incorporation into the Ethiopian State the central government became an important organ of forest allocation, and this situation favoured outsiders and local notables in acquiring private forest rights. The 1975 Land Reform decree extinguished all such claims, bestowed the State with exclusive land ownership rights, and created grassroots Peasant Associations (PAs) with a wide range of land administration roles. The PAs in some localities allocated village forests to rural households. Crucially, though, the State used its land ownership prerogatives to impose a range of measures that went contrary to the forest access interests of the local people. Formal state tenure notwithstanding, traditional principles and channels of forest access such as territoriality, patrilineal descent, and share cropping continue to play critical roles in the local tenure scene. These locally tailored mechanisms also command the protection and enforcement to which other formally recognised forest access channels have been accorded. The factors that permitted the co-existence of formal and informal means of access have also called for the involvement of traditional community-based organisations (CBOs) alongside state sponsored ones in the mediation of local access provision and dispute settlement. The empirical analysis underscores that local people stake forest resources with the view to producing forest goods, which are found to be important livelihood resources. Forest dependency, however, reflects the socio-economic differentiation existing in the study communities. The operational implications which the research draws are based primarily on the observed high degree of dependence of local people on the forest for their livelihoods and the communal ethos that characterise forest access provision and tenure enforcement. Finally, the influence of past patterns of access principles on the current situation; the divergent outcomes of the forest use process; and the local importance of forest goods has enabled the research to identify issues that would enrich the discourse on common property theory. These centre on the relevance of 'stewardship' in the study of resource access; the utility of examining inter-CBO interactions in the analysis of CPR access and management; the need to look beyond the 'tragedyTcomedy' dichotomy in the conceptualisation of resource management outcomes; and the desirability of re-orienting the discourse on CPR analysis towards development ideals contained in the notion of'the sustainable community'.

No description available.

There are many accounts of slope failures on blanket bogs, but their nature and controls are poorly understood. This study investigates the mechanisms of blanket bog failure on Cuilcagh Mountain, north-west Ireland, and identifies the critical factors affecting the stability of peatland hillslopes. This is achieved by means of extensive field investigations involving hydrological monitoring, soil sampling and comprehensive laboratory analyses to determine the physical, hydrological and geotechnical properties of the blanket peat. The results from these investigations form the basis of hillslope hydrology and slope stability modelling using finite-element modelling programmes (commercial SEEP/W and SLOPE/W software). A total of 47 failures scars were identified on Cuilcagh Mountain involving an estimated 300,000 m3 of peat. Detailed field investigations revealed two main types of peatland slope failure: shallow translational peat slides associated with the failure of clay underlying the blanket peat, and bog flows in which failure occurs as a slurrytype plastic flow with the failure zone located within the peat. Peat slides were more prevalent on the steeper slopes (7.0-17.00) of Cuilcagh, whereas bog flows were found exclusively on low gradient slopes (1.5-7.50) with deep accumulations of peat (typically up to 2.5 m). Previously it had been suggested that bog failures were confined to steep slopes or peripheral areas of blanket bogs. However, on Cuilcagh Mountain they appear to be an integral part of the natural evolution of the main peatland, with the presence of many failure scars at different stages ofre-vegetation and recovery. Conventional methods of slope stability analysis (Factor of Safety using limit equilibrium methods) were found to be adequate for use on peat slide failures, but were not as suitable for analysing the slopes prone to bog flows. Sensitivity analyses indicate that cohesion of the failure material (Le. the catotelm peat for bog flows and the underlying clay for peat slides) is the most critical factor contributing to slope failure. A reduction in cohesion is thought to be related to decomposition andlor progressive failure of the peat, or weathering and creep of the underlying clay. Increased overburden pressure from continuing peat accumulation is also an important factor in reducing the overall stability of a peatland slope. The initiation of bog flows and peat slides can occur from the progressive failure of the material in question, but there is more evidence to suggest that both types of failure are more frequently initiated as a result of a specific trigger event usually associated with high intensity rainfall.

No description available.