There is major concern that river temperature changes driven by a changing climate and associated hydrological changes will have profound impacts on freshwater ecosystems. To identify the rivers most sensitive to change and implement effective strategies to mitigate high thermal extremes, this thesis aims to improve understanding of the influences of hydrometeorology and riparian landuse on river temperature dynamics, controls and processes within a UK context. Four studies are presented within a multi-scale research design which aimed to improve understanding of: (1) spatial patterns and inter-annual variability in the shape and magnitude of annual river temperature regimes across England and Wales, and regime sensitivity to air temperature and river basin properties, (2) the effects of riparian vegetation on water temperature under a range of hydrometeorological conditions, (2) the processes by which cool water refugia are produced beneath semi-natural, deciduous forest canopies, and (4) how minimal riparian planting can be used to produce thermal refugia in reaches of differing aspect and hydraulic characteristics. The aims are achieved by combining observational, statistical and deterministic modelling techniques. The outcomes of the research contribute significant new knowledge and tools for evidence based management of river and stream temperature under present and future climates.

The long term contamination of groundwater resources by dense non-aqueous phase liquids (DNAPLs) such as chlorinated solvents is an increasing problem being faced throughout the industrialised world. The transport and eventual fate of these compounds in the subsurface is controlled by the nature of the chemical spillage, the hydrogeological characteristics of the aquifer media and physiochemical properties of the particular contaminant. Geographic Information System (GIS) based risk assessment tools are developed for use with the UK’s Permo-Triassic Sandstone aquifer in order to assist stakeholders make informed decisions on the best use of groundwater in high risk areas and assess the value and management options for resources that are coming under increasing pressure from chlorinated solvent DNAPL contamination. Both semi-quantified and quantified probabilistic methods are presented with associated case studies using the best available data for regions of the UK where high densities of chlorinated solvent users industries combine with valuable groundwater resources. However, attempts at validation of the methodologies are hindered by availability of information on a regional scale, in particular the difficulties in collection and collation of historical land-use data is seen as a major hurdle to the accurate prediction of areas and resources at risk. Nevertheless the tools are potentially useful for guiding regulators and decision makers in the water industry to prioritisation of sites for site specific studies.

Morphological analysis and mapping of Loch Lomond Stadial moraines at five key sites, Torridon, Rannoch Moor, Tyndrum and Strath Fillan, the upper Forth Valley and the east Loch Lomond basin has allowed the genetic interpretation and inferences of climatic significance to made. Hummocky moraine is found at three of these sties, Torridon, Rannoch Moor and Tyndrum, where they are interpreted as polygenetic in origin. The spatial organisation and morphology of hummocky features investigated in Torridon allows the differentiation of cross-valley orientated marginal moraines and the more numerous streamlined features with a down-valley orientation interpreted as flutings. As the flutings are superimposed on the cross-valley moraines they are thought to post-date moraine formation. The spatial organisation of glacial landforms in Torridon therefore represents a palimpsest landscape. Mapping of moraines in the Rannoch Moor basin suggests that this was a major centre of ice convergence rather than accumulation during the Loch Lomond Stadial. Ice mainly accumulated in the corries in the mountains to the west of moor from where it flowed to coalesce as an upland icefield. Ice is thought to have reached a sufficient volume in the Rannoch Moor basin to flow down valleys as outlet glaciers. Hummocky features found at Tyndrum and Strath Fillan have a polygenetic origin and include the remnants of eskers, hummocks produced by local ice stagnation, marginal moraines, and lateral moraines which have been modified by paraglacial debris flow. Large terraces at this sites are interpreted as kame terraces with pitted and channelled surfaces. Local ice stagnation is thought to have occurred during a regional pattern of active deglaciation.

With growing concerns over future climate change, the need to understand past climate variability has become an important topic of research. In this thesis, a gap in knowledge of the transition to modern climatic conditions during the mid-Holocene is identified and addressed. Mid-Holocene atmospheric moisture availability has been reconstructed from five raised mires (Kortlandamossen, Tore Hill Moss, Raeburn Flow, Gällseredsmossen, and Misten Bog) located on geographical and climatological gradients across northwest Europe. In this thesis, a new testate amoebae-based palaeohydrological transfer function for south-central Sweden and an improved indicator-weighted Hydroclimatic Index (HCI) were created in order to establish univariate measures of mid-Holocene bog surface wetness (BSW). Together with detrended correspondence analysis, the HCI and testate amoebae transfer function were applied to palaeoecological data from the five bogs, in order to reconstruct climatic variability across northwest Europe from c. 9000 before present (BP) until c. 3500 BP. A series of wet and dry excursions of the bog surfaces were identified on all five bogs. These BSW changes were compared with palaeoclimatic evidence from the wider literature on a local, regional, continental and hemispheric scale. Throughout the early- to mid-Holocene, increased BSW on Misten Bog closely coincided with episodes of reduced SST in the North Atlantic. A similar link was established between SST and BSW on Raeburn Flow and Gällseredsmossen, following the end of the Holocene Thermal Maximum (HTM). The results from the analysis demonstrate that the HTM occurred asynchronously across northwest Europe. Reconstructions from all five bogs, except Misten Bog, showed a prolonged dry phase on the bog surface starting prior to c. 7000 BP. The end of the HTM occurred between c. 5600 BP and c. 4800 BP on all sites except Kortlandamossen, where regional environmental mechanisms delayed the end of the HTM. A climatic boundary at the end of the HTM was detected around 57ºN, with sites south of 57ºN experiencing the termination between c. 5600 BP and c. 5300, while it occurred between c. 4800 BP and c. 4400 BP on the sites north of this latitude. The only period when all five sites displayed similar BSW changes was between c. 4400 BP and c. 4000 BP, a period of global climatic change. A major wetting on the bogs during this time coincided with increased BSW and glacial advances across Europe as well as high lake levels in France and Switzerland.

Surface albedo is one of the critical parameters required by studies of surface energy balance and climate models. Albedo is defined as the ratio of outgoing radiances to incoming irradiances over hemispherical view-illumination geometry. Remotely sensed albedo is usually based on multiple view angle observations and a Bidirectional Reflectance Distribution Function (BRDF) model. The accuracy of remotely sensed albedo depends on a variety of factors of which the main ones are the accuracy of atmospherically corrected observations, the reliability of observations, and the validity of the applied BRDF model. Fine spatial resolution airborne and satellite data are valuable for the validation of coarse spatial resolution satellite albedos as they may be validated using field measurements with higher reliability. In this study, a variety of remote sensing data and field measurements were used to estimate, validate and analyse albedo at different spatial resolutions. The main aim was to validate the MODIS albedo product under UK conditions using the methods of direct and indirect comparisons with other available data. The source of the fine spatial resolution data used was the NCAVEO Field Campaign 2006 that took place at the Chilbolton calibration test site in southern England. The CHRIS/PROBA albedo was used as a fine spatial resolution (34 m) albedo map to investigate the spatial variation of albedo. The results of this investigation provided valuable information about the possibility of the extension of the obtained albedo map from CHRIS/PROBA data. The MODIS albedo product with a coarser spatial resolution (500 m), relative to the NCAVEO datasets, was compared with the CHRIS/PROBA albedo map to examine the effect of spatial scale on the accuracy of albedo (direct comparison). The uncertainties in the obtained albedo maps, from both MODIS and CHRIS/PROBA, were mainly examined by testing the accuracy of the input reflectance data and the applied BRDF model (indirect comparison). The results showed the accuracy of the MODIS albedo product inferior to that claimed by the MODIS team.

River bank erosion models are a fundamental requirement for understanding the migration and evolution of river meanders, estimating the potential for land-loss and threat to floodplain infrastructure, and predicting the delivery of contaminated floodplain sediments to aquatic ecosystems. While progress has recently been made in understanding and modelling processes controlling large-scale mass failure, less attention has been paid to the role that fluvial erosion plays in bank retreat. This project aims to address this gap by developing a new fluvial erosion model. Recent developments in bank erosion monitoring technology, and in the quantification of the bank erodibility parameters using jet-testing devices, offer the means of determining fluvial erosion rates and bank erodibility. However, the missing link remains the need to obtain highresolution, spatially distributed, flow data to characterize the near-bank fluid shear stresses that drive bank erosion. One possible solution is to use Computational Fluid Dynamics (CFD) models as a substitute for empirical data. Herein I evaluate a series of three-dimensional CFD simulations for a meander loop on the River Asker at Bridport in southern England. CFD models under specific steady peak flow conditions were developed using Fluent 6.2, with peak flow discharge estimates obtained from an adjacent gauging station. All the models obtained from the three examined flow events were successfully verified and validated using clearly defined and structured procedures. The modelling results indicated that the main qualitative features of the flow remain even as flow discharge varies. However, notable differences were observed between the examined flow events, such as, a general increasing of velocity and shear stress throughout the reach as flow stage is gradually increased, a slight reduction in the size and extent of separation zones at bank full stage, a movement of impingement points further downstream, and a continuation of the secondary flow within the fast streamtube further towards the bends exits. Bed/bank shear stress is mostly seen to decrease at shallow riffles as discharge approaches bankfull, while pools experience an increase in bed/bank shear stress with increase in discharge. Zones of higher bed/bank shear stress extend and combine, while marginal recirculation zones and areas of relatively low bed/bank shear stress generally reduce in area to form discrete locations for erosion and deposition phenomena. At bank full stage, the magnitudes of velocity and simulated shear stresses within the inner bank separation zones are found to be higher than those observed under low flow conditions and they may be sufficient to result in the removal of accumulated sediments into the main downstream flow. The presence of regions of high velocity in the form of a streamtube, especially along the outer banks, creates high shear stresses within these areas. As a result, outer bank migration rates are likely to be relatively high in bends with inner bank separation zones.

The standard model of headland formation assumes a coastline with discordant geology, where the less resistant rock is eroded at a higher rate than the more resistant geology. The indentation of the coastline will continue to increase until variations in wave energy due to refraction balance with the variation in rock strength and beach volume. On soft cliff coasts, where no systematic variations in cliff lithology or strength exist subtle headlands are still seen. Several examples of this can be seen on the southwest coast of the Isle of Wight, a coastline of complex interbedded soft rock lithology. Its relatively straight planform is punctuated by three established and one potentially emerging headland. All of these headlands are fronted by locally elevated intertidal shore platforms. It was hypothesised that these platform potentially act in three ways. Firstly by reducing the amount of wave energy reaching the cliff base, thus reducing local cliff recession rates. The second may counteract the first by increasing the wave energy directed at the cliff base due to refraction, the balance between these two effects will determine if a headland will grow, be maintained or decline. Thirdly by blocking longshore transport of beach sediment, building a protective beach up-drift, while starving the downdrift coast of sediment, potentially accelerating erosion in that area. To test these three possible mechanisms, investigation into the geological and geotechnical properties of the cliff and platform, beach volumes and sediment budget, wave refraction, and historical recession rates was undertaken. The elevation of the shore platform is controlled by their resistance to erosion, which is related to aspects of their lithology and structural geology. These include clay content, mass properties, dip and strike in relation to the orientation of the coastline and the strength of the surrounding beds. Although two of the established headlands, Hanover and Atherfield Points act as a partial barrier to sediment transport the sediment volumes along the coastline were insufficient to significantly influence recession rates. The results of the sediment budget indicate that the low sediment volumes observed are likely to have been consistent over time due to the low inputs of beach grade sediment. Wave refraction modelling revealed that concentration of wave energy occurs towards the established headlands of Hanover and Atherfield Points this is reflected in the higher than average recession rates seen at these headlands. It is concluded that the major control of the formation and evolution of headlands on the southwest coast is the geological and geotechnical properties of the intertidal platforms. Once established these headlands exist in a state of dynamic equilibrium controlled by the persistence of the platform forming beds and the balance between refraction and attenuation of wave energy across the platform surface. These results may have widespread implications on soft cliffed sediment-starved coasts where similar processes are dominant.

A stratigraphic reinterpretation of the Eocene-Oligocene Solent Group is presented here, based on the Whitecliff Bay section of the Isle of Wight, Hampshire Basin, UK. High resolution palaeontological, sedimentologica and mineralogical analyses allow the establishment of facies groups, which are used to demonstrate the presence of seven conspicuous sequences. For the first time, these are tied to an accurate magnetostratigraphic framework. Investigation of the cyclic signal in clay mineralogical data reveals that sea level was controlled by the ~400ka cycle of astronomical (Milankovitch) forcing at this critical period in Earth history, when the change from a greenhouse world to an icehouse world took place. This has also allowed uncertainty surrounding the location of the Eocene-Oligocene boundary within the Solent Group to be cleared up. A major incision event associated with glacial build up at the Eocene-Oligocene boundary is recorded, but is smaller than that predicted by isotope records (Miller et al. 1991), possibly as a result of rapid subsidence rates.

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