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Observation of cause–effect patterns of change in coastal environments provides insights into vulnerable areas and supports prediction and adaptation to flooding and erosion. Historic and periodic (6–8 year intervals) imagery from the Landsat archive is used to investigate transformations in the Atlantic coast of two Scottish islands over the period 1989–2011. Supervised classification of spectrally normalized images followed by change detection and spatial analysis reveals the patterns of change and the location of the most dynamic coastal areas. Quantitative measures of recent shifts and movement rates of relevant coastal lines, such as the lower limit of land-based vegetation, are assessed with the Digital Shoreline Analysis System. While very low rates are indicated for horizontal changes in the position of the lower limit of land-based vegetation (0.3 m y−1), specific areas have been subjected to high rates of coastal progradation as well as erosion (e.g. 2.5 m y−1 at Stilligarry). Informatio...

Dawson, A.G.; Gomez, C.; Ritchie, W.; Batstone, C.; Lawless, M.; Rowan, J.S.; Dawson, S.; Mcilveny, J.; Bates, R., and Muir, D., 2012. Barrier island geomorphology, hydrodynamic modelling, and historical shoreline changes: an example from South Uist and Benbecula, Scottish Outer Hebrides. A partly quantitative reconstruction is provided of the evolution of Gualan Island, a barrier island located between South Uist and Benbecula in the Scottish Outer Hebrides, using historical maps, aerial photographs, and Lidar (light detection and ranging) data. Geomorphological changes over the last approximately 200 years are described together with quantitative changes in the dimension of the barrier island, including rates of shoreline retreat. A series of digital terrain models (DTMs) provided the boundary conditions for a two-dimensional (2D) ocean circulation tide-surge model simulating water level and wave conditions associated with a highly destructive storm that took place during January 2005. During t...

Barrier islands commonly occur in coastal plain and deltaic settings, and a variety of behavioral and stratigraphic models exist. In this paper, a 90 km long barrier island system in the Outer Hebrides of Scotland is identified for the first time. Uniquely among barrier islands, the system rests directly on a planar bedrock (gneiss) surface (a strandflat). This bedrock surface has a profound influence on the morphology of the barrier island chain, and exerts the dominant influence on barrier island form and evolution during transgression. Topographical irregularities on the bedrock surface control both plan and profile morphology of the barrier islands. Under sea-level rise, by barrier migration, sediment is redistributed onshore and alongshore in a strongly three-dimensional manner, determined by topographic variability in the bedrock. The barrier islands represent an endpoint in transgressive barrier island geomorphology that is controlled by the bedrock surface: they are at the upper end of the recognized tidal amplitude for barrier islands; the offshore wave regime is very high-energy; they lack a shoreface; and neither ravinement surface nor transgressive sand sheet are developed. Sediment supply is dominated by offshore-derived skeletal carbonate.

This paper describes some of the changes that affected the coastlines of South Uist and Benbecula following the ‘Great Storm’ of 11 January 2005. The paper considers historical changes in patterns of winter storminess and addresses the issue of whether or not there has been a recent increase in regional storminess, manifested partly by this particular storm. The paper concludes on the basis of available Greenland ice core chemistry data and historical climate data, together with recent meteorological data, that no such increase has taken place. This surprising conclusion is further discussed in relation to current thinking on the nature of recent climate change.

The impact on the marine environment of the operation of the Sullom Voe Oil Terminal and its major port facility in the Shetland Islands has been monitored continuously for more than twenty-five years. The site of this very large terminal straddles a peninsula and the separation of the impact of the port on the sheltered west side (Sullom Voe) and the aqueous discharge from the terminal to the east, into the strong tidal current of Yell Sound, has proven to be advantageous. There are two types of monitoring, statutory (to comply with relevant legislation) and voluntary (to establish good practice and to examine a wider range of impacts e.g. island-wide ornithology). The latter function is undertaken by an independent advisory committee (SOTEAG). Over time, the nature and amount of voluntary monitoring has decreased in response to the long term evidence that both terminal and port operations are having little or no impact on a wide range of habitats and species. Voluntary monitoring also acts as an independent check on both compliance and other forms of environmental assessment. Although the terminal is now operating at less than half its peak capacity, this does not mean that there has been apro-rata decrease in monitoring activity.

Immediately W of the islands of Uist in the Outer Hebrides is a wide, low-gradient submarine shelf on which glacifluvial deposits of Devensian age and calcareous sand accumulated. Following moulding by Devensian ice, the Lateglacial landscape of the littoral zone of the Uists became a series of low-lying bedrock ridges and basins. The analysis of sub-tidal organic deposits has shown that in the early Holocene this landscape supported water bodies, marshes and a vegetation mosaic of Betula-Corylus woodland and Calluna vulgaris-herbaceous taxa open ground. The submergence of this littoral area during the Holocene Marine Transgression, together with wave action typical of the position on the Atlantic margin, led to the transfer onshore of submarine shelf deposits, so creating machair (sand plain) landscapes. This brought about vegetational changes, eventually creating calcareous grasslands. The timing of these events was asynchronous, being location- and site-specific due to variations in the configuration of the littoral zone. Although the date of the initial transfer of sand is unknown, evidence from the sub-tidal deposits indicates that a major incursion of sand, in North Uist, occurred c. 7600 BP (8450–8340 cal BP). The same source also suggests that a further major sand movement took place during the period 5800–4200 cal BP, a period of widespread sand drift in NW Europe. The analyses of the sub-tidal deposits have also reinforced the current theory of machair evolution.

The Sands of Forvie, National Nature Reserve, Scotland is a complex coastal sand dune system which is associated with the dynamic estuary of the River Ythan. The dune system has developed over more than 5000 years. The south part is a peninsula of dunes, sand hills, sand arcs, erosion and deflation surfaces. The north part is superimposed on a rock plateau with a cliff coastline. This plateau is covered in glacial deposits and is essentially an upland heath landscape. Some of the best examples of large active parabolic dunes in Britain are found in North Forvie. The sequence of geomorphic development is described. As a nature reserve with a rich ecology it has been managed for conservational purposes since 1960s. As such it is an excellent case study of how conservational management has changed to become more flexible and more aware of the importance of dynamic processes.

Environmental planning and monitoring for Europe's largest oil terminal at Sullom Voe are reviewed. It is concluded that adverse physical impacts of the terminal have been minimal, and that the Shetland experience has become a model for sound environmental management and prudent co‐operation between the oil industry, local government, and environmental interests.

The coastal wind‐blown sands of the Outer Hebrides, known as machair, are derived from sands of glacial and biogenic origins. These sands were swept onshore in the postglacial marine transgression. The early sands developed as a series of overlapping landform suites, often burying existing soils, marshes and lacustrine deposits. Today, fragments of these terrestrial organic materials with intercalated sand layers outcrop on a few protected intertidal zones where they provide evidence for both coastline erosion and machair transgression. One such deposit at Cladach Mor in North Uist is over one metre thick and extends to low water mark. It has been analysed sedimentologically and palynologically. The results give a chronology for, and show the complex nature of, the inland movement of sand across a loch basin which lay originally landward of the transgressive coastal sand body. Research at this site has prompted a revision of the existing hypothesis of sand movements on to the coastal plains of th...

The wreck of the oil tanker Braer on Garths Ness in Shetland in January 1993 created a major oil spill incident. The short‐term, superficial impact on the coastline was much less serious than might have been expected. Three factors combined to prevent the formation of a large oil slick: (i) the oil was a light crude; (ii) winds and waves were exceptionally strong and persistent; (Hi) the exposed coastline produced strong reflection and turbulence effects. Moreover, this part of Shetland lacks vulnerable landforms such as low‐energy beaches and saltmarshes.

The production of International Maritime Organization (IMO) guidelines could be seen as a reaction to specific major oil spill incidents where the notion of 'places of refuge' was advocated by a number of parties, including media interests. Environmental concerns that would arise in the event of an oil spill at sea depend on the location of the incident and the passage to the place of refuge. Many of the major well-publicised oil spills have been caused by grounding and wrecking on a coastline, and an extensive literature exits in describing both these events and their environmental consequences. Distance from the shoreline can be defined easily by measurement and, in general, the greater the distance from the coast, the more time becomes available to counter the oil spill effects and provide for natural processes to minimise most of the oil pollution problems. Keywords: International Maritime Organization (IMO) guidelines; oil pollution; place of refuge

Aberdeen Beach is an example of a developed and economically important urban shoreline whose inherent natural mobility has been constrained and modified over a lengthy time‐scale by coastal protection practices in order to benefit the city's population. This protection appears to have resulted in the perpetuation of a pronounced marine energy continuum increasing northwards along the beach under a predominantly south‐easterly wave attack. At the north end of the beach, beyond the limit of protective structures and the bay's sheltering headland, the beach extends across the mouth of the River Don in the shape of a free‐forming sandspit. The resultant river‐mouth asymmetry has attendant problems of river‐bank erosion. The free spit solely reflects the true dynamic nature of the unprotected shoreline and in spite of severe short‐term fluctuations in its morphological dimensions, is in a state of dynamic equilibrium with the complex array of incident marine and fluvial processes.

The Caminada-Moreau barrier headland of South Louisiana is a low-profile beach and dune coastline that is transgressing rapidly over the surfaces of the abandoned Lafourche delta complex. With the passage of cold fronts (10–30 times per year) and hurricanes (once every 4 yrs), overwash events occur year round with varying degrees of frequency, intensity and geomorphological modification. This coastline consists of washover and dune surfaces that respond rapidly to overwash impact. The fine sand stored in washover deposits is easily reworked by aeolian processes into a variety of dune forms in the shore-zone that are vegetated rapidly. Geomorphological changes vary according to the position, ground elevation, and surface stability of the dunes. Independent factors are overwash surge elevations, beach gradient and the presence of pre-existing landforms. For ten years detailed surveys supplemented by aerial photographs and videotape surveys have recorded these changes. The analysis of these information sources provides insight into both the general evolution of this distinctive coastline and also the geomorphological interaction of dunes, beaches and washover deposits in different physiographic settings.

Approximately 20 per cent of the coastline of the Highlands (Land lying West and North of the Highland Boundary Fault) excluding islands, is fringed by sand accumulations in the form of dunes, links or machair. Except where sea walls and promenades protect their seaward edge, dunes are intimately linked to beaches, the margin between dune and beach being a fluctuating zone which is dominated in turn by encroaching waves or prograding vegetation. The largest sand surfaces are found in the machair plains of the Uists; long stretches are also found on the Caithness coast, the south coast of the Moray Firth and Aberdeenshire. (Author)

(1967). The Machair of South Uist. Scottish Geographical Magazine: Vol. 83, No. 3, pp. 161-173.

From the Arctic to the Equator the coastal zone is probably under greater and more varied forms of pressure for development than any other land surface. These pressures are not new but there is considerable evidence to suggest that development may be accelerating as the less industrialized nations strive for commercial and industrial growth, and the sophisticated industrial and post-industrial nations find an increasing number of relatively affluent people moving to the coast, either temporarily as tourists or permanently as residents. In general, attention is focused on low, unconsolidated coastal landforms. Partly this is due to the need for relatively level terrain; partly it is related to ease of excavation for harbours, canals and water-based leisure complexes; partly it is related to the prime tourist resource of sand beaches; partly it is related to the need of large industrial and power plants to be near tidewater for cooling water and effluent discharge and partly it is due to lower costs associated with ease of transhipment of raw materials and finished products. A special but increasing form of pressure is now generated by the need to bring the products of the bed and sub-surface of the continental shelves ashore, normally by pipeline.

The importance of coastal geomorphology is increasing as a result of a worldwide movement of people to the coast, where there are wide-ranging developments, from agricultural reclamation to sophisticated industrial operations. There is particular interest in tourist and holiday activities, many of which require massive capital and recurrent cash inputs for protective works. Beach nourishment is a common form of coastal engineering, but many other developments are designed to alter coastal landforms to accord with a perceived optimum usage. Since they are unconsolidated and easily excavated, low beach-type coastlines carry the main impact of these changes. The place of coastal geomorphology in physical geography has never been in doubt but the nature, pace and scale of man-made changes, from equatorial to polar areas, have reinforced its relevance and range of applications.

(1962). Geography at the British association Manchester 1962. Scottish Geographical Magazine: Vol. 78, No. 3, pp. 177-177.