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.

Despite its large volume, Lake Baikal has been experiencing recent changes within its limnological and biological structure, as well as changes within lake water nutrient and dissolved organic carbon concentrations. The biological changes within Lake Baikal include alterations within the distribution and abundance of major phytoplankton and zooplankton groups. These limnological changes are likely to be from both climate warming and anthropogenic impact, particularly over the last few decades. Recent shoreline observations in the South and North regions of Lake Baikal have found large blooms of filamentous green algae, which has been associated with nutrient enrichment from surrounding settlements and growing tourism. This highlights the question as to whether the pelagic regions are similarly showing any signs of anthropogenic driven nutrient enrichment. The aim of this thesis was to examine if pelagic Lake Baikal is showing any evidence of eutrophication and/or response to climate warming. The main themes of the research were to assess the modern-day limnological condition of Lake Baikal in the summer (August 2013) and winter (March 2013) months,and to examine Baikal’s phytoplankton response to nutrient enrichment via the construction of mesocosm experiments. High-resolution limnological change was then reconstructed from sediment cores across the lake. Sites were chosen within pelagic regions, bays and shallow waters nearby river inflows, and palaeolimnological records were used to assess primary production changes and floristic changes over the last few centuries. This timespan enables both natural variability within the system to be explored, and more recent changes pre and post known human influence within the catchment area (c. 1950 AD). The main palaeolimnological techniques applied for primary production proxies were sedimentary algal pigments, stable isotope analysis of bulk organic carbon and diatom valve concentrations. Mercury analyses was also applied to water samples and sediment cores as a pilot study to explore toxic metal pollution at Lake Baikal, due to mining activity along the Selenga River, and examine historic levels of mercury contamination, and examine historic levels of mercury contamination. Both modern-day limnological surveys and palaeolimnological records seem to be showing increasing algal biomass (chlorophyll-aconcentrations) over the last 60 years, with decreasing trends in diatom production (from diatoxanthin pigment concentrations and diatom valve concentrations) in the South basin. Spatial survey data represents a snap shot in Baikal’s limnology in late summer (August 2013), and shows higher than expected concentrations of total phosphorus within the mixing layer, which fall within the meso-eutrophic range. Dissolved organic carbon concentrations seem to now be higher within Lake Baikal’s waters, and both nitrate and silicate concentrations appear to be similar to known previous concentrations at Lake Baikal. A pilot study of mercury concentrations within Lake Baikal waters and sediments, show no signs of mercury contamination from mining activity along the major river inflows, and atmospheric deposition. Experimental results show that within the pelagic regions of Lake Baikal, nitrogen, phosphorus and silicon are influencing algal communities, with Si addition stimulating diatom growth, nitrogen and phosphorus addition stimulating chlorophyte growth, although overall nutrient treatments did not increase chlorophyll-a yield. Interestingly, experimental findings also highlight the potential influence of picocyanobacteria populations on silicon cycling. Concentrations of sedimentary chlorophyll-a concentrations (plus its derivatives) rise prior to major industrial influence within the Baikal catchment region, and stable carbon isotope records show a positive correlation with chlorophyll-a concentrations in the South basin, Selenga and Maloe More sites. Total phosphorus concentrations could be a result of both anthropogenic nutrient pollution, entering into the lake via the Selenga River, and climate driven changes in lake stratification and nutrient utilisation by algae. Results from limnological surveys and palaeolimnological records are thus likely to be reflecting both recent anthropogenic impact and climate change (rising lake water temperatures, declining ice cover thickness and duration and increasing river inflow from permafrost thaw), within the pelagic regions, especially given that recent work provides evidence of toxic cyanobacterial and chlorophyte blooms within the shallow waters of Lake Baikal. For the Maloe Moresite, which is a bay of the Central basin, results show a rise in sedimentary chlorophyte pigments post 1950 AD, suggesting that this bay region of Lake Baikal is currently being affected more than deeper water sites, by human influence, showing signs of eutrophication due to a switch in algal community composition.

A conceptual model of the regional hydrogeology of the White Peak, considered fundamental to the understanding of the local (Wye) catchment has been presented. Specific to the local catchment, an investigation of the karst hydrogeology has been carried out in the context of its geological setting using results from: tracer experiments, chemical analyses of spring water, and hydrograph analyses; alongside detailed consideration of speleogenetic processes and terrain evaluation. Derived from these studies, a conceptual model has been developed, which represents the catchment hydrogeology in a number of hydrogeological units. Their attribution reflects the lithological differences and material responses to both stress and mineralization that have exerted significant influence on speleogenetic processes in the catchment. The units exhibit different recharge, through-flow and resurgence characteristics. Speleogenetic processes in some of the bedrock units support the inception horizon hypothesis. Flow paths typically pass through more than one hydrogeological unit. Lead-zinc-fluorite-baryte mineralization is associated with the dominant hydrogeological unit on the eastern side of the catchment. The mineral deposits were subject to several phases of exploitation facilitated by dewatering via drainage adits (soughs). Records pertaining to the soughs have been used to contribute to an understanding of the changes in groundwater levels as a consequence of mineral exploitation. A case study focused on Lathkill Dale has been used to test the catchment model and further explore human impacts on the hydrogeology. The major contribution of this work is in furthering the understanding of the hydrogeology and speleogenetic processes operating in the catchment. This is supplemented by additional contributions to the understanding of the distribution of superficial deposits within the catchment. Speculation regarding mineralizing processes; geomorphology; functioning of karst aquifers; seasonality of the groundwater chemistry; climate change, and the engineering properties of the bedrock may encourage further research in these areas.

This study investigates a Devensian glacial conundrum, the provenance of the Norber erratics in North Yorkshire, and the origins of a post-Devensian-deglaciation landform, pedestal rocks with Carboniferous limestone pedestals in England, Ireland and Wales. Investigations to determine the provenance of the Norber erratics were undertaken in a study area of about 2000ha. Mapping erratic dispersal and measuring striae strike revealed that the provenance is Crummackdale, and that Devensian ice crossed over only the Crummack, Sowerthwaite and Austwick formations en route to Norber. Petrographical and physical surveys further revealed that the erratics are derived from the Austwick Formation only, and that provenance is a glacially-plucked ‘amphitheatre’ in the vicinity of the Old Limekiln (SD 770707). Investigations to determine the formation of post-Devensian-deglaciation pedestal rocks with Carboniferous limestone pedestals were undertaken at 19 sites in England, Ireland and Wales, where 162 pedestal rocks and a pedestal rock field were examined. The study was divided into two, the formation of perched and mushroom pedestal rocks. An examination of weathering and erosion processes at Norber, where only perched pedestal rocks with vertical sidewalls are found, revealed that lowering of the inter-pedestal limestone surface has taken place primarily in a sub-regolith karstic environment, and that little or no pedestal formation occurred prior to ca.10000BP. In contrast, the lowering of the inter-pedestal limestone surface about perched pedestal rocks with sloping sidewalls, such as at Scales Moor (North Yorkshire) and the Burren (County Clare), has taken place primarily in a subaerial environment. Moreover, pedestal formation commenced in ca.14500BP in England and Wales, and ca.13700BP in Ireland. The pedestals of mushroom pedestal rocks have formed due to lateral dissolution under regolith that has largely been eroded, probably following deforestation in ca.3000BP.

No description available.

The establishment of an accurate global carbon budget and the consequent ability to understand and predict future environmental change is dependent on knowing the strength of terrestrial sinks and sources of carbon. Regenerating tropical forests are one of the major terrestrial carbon sinks as they are found growing quickly and are sequestering carbon from the atmosphere. Total forest biomass (which includes above and below ground living mass of plants and litter) is a measure of terrestrial vegetation carbon content. It follows that to determine the strength of terrestrial carbon sinks we require information on the location, extent, biomass and biomass change of regenerating tropical forests. Near-constant cloud cover over the tropics and an insensitivity to biomass change at relatively low levels of biomass has limited the use of optical imagery but not Synthetic Aperture Radar (SAR) imagery for the provision of such information. The biophysical properties of regenerating tropical forests are related to the temporal, spatial, spectral and polarisation characteristics of SAR backscatter (a°) and this formed the framework for this thesis. The objectives were to (i) detect biomass accumulation using the temporal characteristics of 0°, (ii) use the spatial characteristics of a° (texture) to increase the strength of the a7biomass relationship and (ill) use the spectral and polarisation characteristics of 0° to classify a surrogate for biomass in regenerating tropical forests (optical Landsat TM data were also included to widen the spectral analysis). Although no biomass change was detectable using temporal 0°, a seasonal pattern in 0° for young regenerating forest was detected, as a result of changing water content in both vegetation and soil. The influence of recent rainfall was confirmed to be an important source of variation in a°, suggesting the use of SAR data from the dry season only. Using simulated data, seven texture measures showed potential for strengthening the a7biomass relationship. However, when applied to real SAR data only GLCM (Grey Level Co-occurrence Matrix) derived contrast strengthened the a7biomass relationship. The addition of GLCM-derived contrast to a° potentially increases the accuracy of biomass estimation and mapping. Neural networks can be used for the classification of land cover in tropical forest regions. Classification accuracy of around 80% was achieved using combined multiwavelength and multipolarisation SAR and Landsat TM bands for 4 land cover classes (pasture, mature forest, 0-5 years old regenerating forests and 6-18 years old regenerating forest). These results demonstrated that multiwavelength and multipolarisation SAR data could provide information on the location, and extent of regenerating tropical forests. However an increase in the accuracy of biomass estimation relies on the optimal use of additional information that resides within the spatial, spectral and polarisation domains of SAR data.

Spaceborne Synthetic Aperture Radar (SAR) sensors obtain regular and frequent radar images from which ground motion can be precisely detected using a variety of different techniques. The ability to remotely measure slope displacements over large regions has many uses and advantages, although the limitations of an increasingly common technique, Differential SAR Interferometry (D-InSAR), must be considered to avoid the misinterpretation of results. Areas of low coherence and the geometrical effects of mountainous terrain in SAR imagery are known to hinder the exploitation of D-InSAR results. A further major limitation for landslide studies is the assumption that variable rates of movement over a given distance cannot exceed a threshold value, dependent upon the SAR image pixel spacing, the radar sensor wavelength and satellite revisit frequency. This study evaluates the use of three SAR image modes from TerraSAR-X and ENVISAT satellites for monitoring slow-moving landslides in the densely vegetated Three Gorges region, China. Low coherence and episodically fast movements are shown to exceed the measureable limit for regular D-InSAR analysis even for the highest resolution, 11-day interferograms. Subsequently, sub-pixel offset time-series techniques applied to corner reflectors and natural targets are developed as a robust method of resolving time-variable displacements. Verifiable offsets are generated with the TerraSAR-X imagery and the precise movement history of landslides is obtained over a period of up to four years. The capability to derive two-dimensional movements from sub-pixel offsets is used to infer a rotational failure mechanism for the most active landslide detected, and a greater understanding of the landslide behaviour is achieved through comparisons with likely triggering factors and 2D limit equilibrium slope stability analysis.

National efforts to reduce energy dependency on fossil fuels have prompted examination of macrotidal nearshore zones around the UK for potential tidal stream resource development. Although a number of prospective tidal energy sites have been identified, the local hydrodynamics of these sites are often poorly understood. Tidal-energy developers rely on detailed characterisation of tidal energy sites prior to device field trials and installation. Although first-order appraisals may make macrotidal tidal straits appear attractive for development, detailed, site-specific hydrodynamic and bathymetric surveys are important for determining site suitability for tidal stream turbine (TST) installation. Understanding the ways in which coastal features affect tidal velocities at potential TST development sites will improve identification and analysis of physical constraints on tidal-energy development. Ramsey Sound (Pembrokeshire, Wales, UK) will soon host Wales’ first TST demonstration project. However, the local hydrodynamics of the sound have been underexamined. Ramsey Sound experiences a marked tidal asymmetry, with local bathymetric features that affect flow fields which are spatially heterogeneous in three dimensions. Using Ramsey Sound as a case study, this thesis has three objectives: (1) to examine the wake created by submerged objects through field- and laboratory-based measurements, (2) to experimentally investigate the effect of submergence on wake development and decay downstream of a conical island, and (3) to develop a TST suitability tool, which examines the effects of velocity, water depth and bed slope on power availability within a macrotidal coastal area. Laboratory experiments have shown that submergence level is an important parameter controlling wake structure and extent, and that changes in submergence level affect both the 3-D flow structure in the near wake and the 2-D far wake of islands. Analysis of physical and hydrodynamic characteristics in Ramsey Sound, including tidal velocities across the swept area of the pilot TST, vertical shear in the stream flow, estimated power output, water depth and bed slope, suggests that the spatial and temporal variability in the flow field may render much of Ramsey Sound unsuitable for tidal power extraction. Although the resource potential depends on velocity and bathymetric conditions that are fundamentally local, many prospective tidal energy sites are subject to similar physical and hydrodynamic constraints. Results of this study can help inform site selection in these complicated, highly dynamic macrotidal environments.

Housing is one of the key issues that normally forefront the scene when considering challenges of urbanisation and urban growth. It is a fundamental aspect of human life and a major factor in delivering healthy and attractive communities as it serves to define the life space of individuals. Increasing interest is now shown towards the study of how people think of their housing and how it affects their lives. Therefore, measuring the housing quality has become an important tool to assess the efficiency of housing provision and the extent to which people are satisfied with it. This research is about examining housing quality and exploring the set of aspects through which it influences people’s quality of life (QOL). It stems out of a general concern about the state of life in cities and the general factors that shape and outline such life. It starts from some apparent observations regarding the socio-economic transformations accompanied with urban growth and development taking place in Amman, capital of Jordan, and the alterations that are soundly reforming the profile of housing provision in the city. Such alterations are seen to be adjoined with implications and challenges that are strongly influencing the state of housing sector and the overall state of life that people are living in the city. The research aims to critically investigate housing quality and the impact it has on QOL experienced by residents in Amman. In doing so, it employs an integrated conception of housing quality that poses three types of qualities: quality of provision, quality of context and quality of dwelling, and explored the implications of each of these qualities, in order to provide an overarching understanding of the influences of housing on QOL. Such understanding implies identifying the most influential aspects within each of the three types of qualities, and interpreting the impact of these aspects on QOL, taking into consideration the impact of the socio-demographic and housing provision factors. The research adopted a mixture of quantitative and qualitative methods to collecting and analysing data in order to achieve a deep understanding of the influence of housing quality in QOL. Results revealed a variation in the extent and nature of influence posed by the different housing quality components and a disparity in the response of households towards these components attributed to the differences in the socio-demographic and housing acquiring factors. It is argued that the perception of good QOL can be strongly derived from good housing quality and the set of material, social and psychological benefits obtained from it. It is suggested that the current housing provision system in Amman is in need of a reappraisal, in order to come out with a responsive housing provision scheme that provides more flexibility, equity, diversity and capability to choose among different community groups, which can help archiving better QOL.

This thesis considers the geochemical links between geophysical survey results from, and responses of barley crop growth to, the existence of plough-levelled archaeological sites. It takes as a starting point the results of magnetic and resistivity surveys undertaken at three sites in the Upper Clyde Valley, Lanarkshire, Scotland. Two of the three sites produced geophysical results that closely matched the evidence for archaeological remains recorded using oblique aerial photography. The third site was largely unresponsive to geophysical prospection techniques. These mixed responses prompted a closer examination of why barley crops respond to plough-levelled remains, and why the geophysical data gathered tend to correlate with the growth responses. To allow an examination of the growth responses, a series of pot-based growth experiments were carried out under glasshouse conditions, and these were followed up by ICP-MS analysis of the plants and the archaeological soils in which they had grown, in an attempt to link any changes in elemental compositions with the growth responses, and to the geophysical responses recorded at the soil sampling points or for the features from which the soils were taken. The results of the experimental work revealed that although soil moisture content has a role in the development of both crop marks and geophysical anomalies, other factors are also involved, including changes in elemental concentrations in soils and plant material, soil pH changes and the redox potential of the archaeological soils.