M.R. Phillips

Short-term beach rotation, wave climate and the North Atlantic Oscillation (NAO)

Beach profile surveys, offshore wave climate and variations in atmospheric conditions have been utilized to assess a short-term beach rotation phenomenon in a headland embayment Tenby, West Wales. Beach rotation, expressed by subaerial volumetric change, was shown by a negative phase relationship between beach extremities (r = —0.67), while cross-correlation at a one-month timelag increased statistical significance (r = 0.84). Due to beach aspect, gale wave heights decreased as wave direction rotated to the south (R2 = 0.4) and west (R 2 = 0.65), while offshore wave direction influenced change at the southern and northern extremities (R2 = 0.52 and 0.34, respectively). Shelter from offshore islands and Giltar Headland contributes via wave diffraction to accretive, erosive and rotational patterns, and these are sensitive to variations around the predominant wave direction (229°). A southerly shift induces north/south sediment movement, as waves diffract around the offshore islands, while a westerly change results in south/north sediment movement (i.e. beach rotation), as diffracted wave domination transfers to the headland. A general gale wave height reduction occurred when the North Atlantic Oscillation (NAO) was weak or in a transitional phase between positive or negative phases (R2 = 0.69 and R2 = 0.72, respectively). Morphological change was also attuned to atmospheric variation where a reversal in beach rotation was influenced by variations in positive and negative NAO/volume correlations and longshore profile location (R2 = 0.54 and 0.69, respectively). The results of this study have wider implications for coastal management; it is suggested that models developed in similar systems elsewhere will form the basis of human intervention or no active intervention strategies.

Disappearing destinations: Climate change and future challenges for coastal tourism.

Section 1. The growth and management of Coastal Tourism Destinations - The theoretical context 1. Managing the coastal zone 2. Current definitions of tourism 3. Definitions and typologies of coastal tourism destinations Section 2. Disappearing destinations - Climate change and coastal tourism - predictions impacts and risks 4. Current assessments and definitions of climate change 5. Climate change and its predicted impacts on coastal tourism 6. Climate change, tourism and the media 7. Assessment of current risks Section 3. Managing coastal tourism destinations: Current assessments and scenarios - Reports from existing case examples 8. Coastal tourism management: USA and the Americas 9. Coastal tourism management: Europe 10. Coastal tourism management: Australasia 11. Coastal tourism management: Asia Section 4. The future management of coastal tourism destinations - Overview of management and policy actions: choosing mitigation and ameliorative measures 12. Responding to climate change: Future management and policy choice 13. Conclusions.

Depth of Closure and Shoreline Indicators: Empirical Formulae for Beach Management

Abstract In 1997, the effects of severe erosion along the Penarth, Wales, UK, foreshore became apparent when the beach surface fell to critical levels. A 240 m length of beach, bounded by a slipway, sea wall, and pier, was surveyed each September and April between 1997 and 2002 to assess summer and winter changes. Results in September 1997 showed that sediment transport was southerly in direction, whilst by September 2002, there had been a consistent return to the traditionally accepted south-to-north longshore drift, verified by significant differences in longshore gradients (t = 2.664; degrees of freedom [DF] = 6; p < 0.05). Analysis of changes in beach morphology has shown that erosion induced a southerly movement of beach contours, and a northerly movement was produced by accretion. Foreshore analysis has resulted in important regression models representing the variation of the shoreline indicator mean high water (MHW) with both shoreline position (mean beach level) and gain/loss of beach material. The cross-shore position of the depth of closure (DoC) was 50 m seaward of the survey line, at a water depth of 5.5 m. Results from analyses of cross-shore profiles verified temporal variations in back beach level with little variation beyond the DoC. Furthermore, there was significant correlation between the two shoreline indicators, MHW and DoC (84%). This correlation, combined with a derived equation for a management response parameter (MRP = 17.035 + tan−1 (x14 − x6)/240[°]), produced simple tools to rapidly assess beach health. Results were compared with past data for interpretation of significance, and management strategies based on tabulated MRP values are suggested. A general form of this equation has been developed for testing at other beach locations, which should have significance for worldwide beach management.

Integrated Coastal Zone Management (ICZM): a review of progress in Portuguese implementation

Coastal areas are the focus of intensive urbanisation and tourism and are subject to changing physical processes causing significant natural environment modifications. It is in this context that the European Commission (EC) developed the Integrated Coastal Zone Management (ICZM) Recommendation and invited coastal Member States to produce national implementation strategies. Its general aim of sustainable coastal development was based on policy integration in cooperation with all stakeholders in an informed and participatory context. Portugal responded to the EC request by creating, approving, and adopting the national ICZM strategy. This paper focuses on Portuguese experiences putting the ICZM recommendation into practice and begins with a brief overview of community guidelines, national legislation, and implementation. Subsequently, governance mechanisms are discussed and best practice identified. From an assessment of Portuguese ICZM progress and lessons learned, conclusions and recommendations for improved effectiveness included: strengthening governance; improving sustainable decision-making processes supported by technical and scientific knowledge; and securing financial sustainability.

Desalination impacts on the coastal environment: Ash Shuqayq, Saudi Arabia

Ash Shuqayq (Saudi Red Sea coast) is approximately 28km long and characterised by narrow rocky headlands with intermittent pocket beaches. Fifty-two sediment samples from six different environments (beach, dune, sabkha, tidal/lagoon, offshore and wadi) were analysed. Testing showed that beach and dune sands are mainly medium to fine grained, with some very coarse sand (MZ=-0.59ø). Both beach and dune sands are moderately well to moderately sorted, although some are poorly sorted due to an influx of wadi sediments. Sediment source together with littoral reworking contributed to grain size variation. Carbonate content varied between 1.5% and 23%, whilst the organic content varied between 1.1% and 13%. Spatial analysis showed increasing southward carbonate and organic content, with both correlated (r=0.57). Sabkha sediments had significantly higher carbonate percentages (t=2.898; df=18; p<0.01) and results suggested origins are similar for both UAE Arabian Sea and Saudi Arabian Red Sea coasts. X-ray diffractions show beach and dune sediments are mainly composed of detrital quartz and plagioclase feldspar with uncommon amounts of chlorites. Analysis of sediment characteristics, composition and shoreline distribution alongside coastal processes, indicate that high chlorite levels are probably caused by desalination processes. Due to human and ecosystem health consequences and the likely increased demand for desalination plants, similar analyses should be undertaken elsewhere, e.g. the Mediterranean.

Beach Response to a Total Exclusion Barrage: Cardiff Bay, South Wales, UK

Abstract The regeneration of 1100 ha of derelict industrial land to the south of Cardiff included the construction of the 1.1-km-long Cardiff Bay Barrage (completed November 1999), which impounded two major South Wales rivers. A 160 m groyned beach, composed of four groynes and three bays, adjacent to and seaward of the barrage breakwater was monitored between September 1997 and September 2002 to assess pre- and postconstruction beach evolution. Overall, mean beach levels increased throughout the five-year period, resulting in a net gain of beach covering equivalent to 818.8 m3 (1800 tonnes). After barrage completion, both longshore and cross-shore gradients became less volatile and increased beach levels in the bay nearest the breakwater, prevented tidal action and erosion at the cliff toe. This was a significant change from initial conditions that was verified by parametric and nonparametric tests at the 99% confidence level. Regression analysis determined that there were significant temporal relationships. Spatial analysis identified two highly significant longshore trends with respect to distance from the breakwater and showed that this influence decreased with distance. More than 72 m from the breakwater, the regression equation (R2 = 96%) modelled a trend of falling beach levels caused by net sediment transport. Conversely, from 72 m to the breakwater, beach levels increased at a rate greater than twice the fall in the previous section (R2 = 92%). These trends were further supported by significantly greater level differences across the second groyne. Impacts of temporal and spatial trends, especially subsequent to barrage completion, were evidenced by the change in beach morphology and similar contour orientation in all three bays. Models were developed and proposed as management tools to identify potential changes in coastal processes, as well as the rate of change of the barrages upstream influence with respect to net sediment flow. Groyne removal was suggested to provide recreational beach space.

Geomatics for Integrated Coastal Zone Management: multitemporal shoreline analysis and future regional perspective for the Portuguese Central Region

ABSTRACT Cenci, L., Disperati, L., Sousa, L.P., Phillips, M. and Alves, F.L., 2013. Geomatics for Integrated Coastal Zone Management: multitemporal shoreline analysis and future regional perspective for the Portuguese Central Region. Proceedings 12th International Coastal Symposium (Plymouth, England), Journal of Coastal Research, Special Issue No. 65, pp. 1349–1354, ISSN 0749-0208.--> Shoreline mapping and change detection are critical for Integrated Coastal Zone Management (ICZM) and all that it represents. This research utilized previous studies that combined both Remote Sensing and Geographical Information System (GIS) techniques to assess, map and forecast shoreline evolution from short-term perspectives. The study area is located in the central region of Portugal, between the counties of Ovar and Marinha Grande (circa 140 km) and the time period assessed was from 1984 to 2011. Historical data were used to calculate advance and retreat rates in order to support environmental scenarios for the Portuguese Central Regions Coastal Management Plan. To ensure accuracy, a repeatable procedure was validated using Landsat TM and ETM+ satellite images, which were subsequently enhanced and elaborated by Remote Sensing analyses to detect and extract shorelines. They were subsequently integrated within an Esri ArcGIS software application (DSAS - Digital Shoreline Analysis System) to determine and predict rates of coastline change. Graphical DSAS plots identified coastline phases and shifts and were used to simulate the 2022 coastline scenario. These results will be integrated into the Coastal Zone Management Plan (Horizon – 2022). Importantly this methodological planning approach provides visual coastline change information for regional decision-makers and stakeholders.

Maintaining a way of life for São Miguel Island (the Azores archipelago, Portugal): an assessment of coastal processes and protection.

Traditional hard engineering structures and recently emerging soft engineering alternatives have been employed to protect vulnerable coastlines. Despite negative publicity, they have ensured community survival where socio-economic benefits outweigh adverse impacts. This is especially true for Small Islands (SI) where increasing sea levels and storm intensities threaten already limited land availability. This paper presents coastal vulnerability in São Miguel Island (the Azores SI archipelago) and considers SI issues with regard to coastal land loss. Regional wave statistics using 1998 to 2011 wind record showed: periods ranging from 7 to 13s (circa 83%); wave heights between 1 and 3m (circa 60%); and increasing trends in westerly (p=0.473), easterly (p=0.632) and southeasterly (p=0.932) waves. Sea level analyses between 1978 and 2007 indicated a statistically significant rising trend (2.5 ± 0.4 mm yr(-1); p=0.000), while between 1996 and 2007 it was 3.3 ± 1.5 mm yr(-1) (p=0.025), agreeing with other global sea level studies. Based on 2001 and 2008 population data and using zonal statistics, circa 60% of the Islands population was found to reside within 1 km of the sea and the percentage of total population was linearly correlated with distance from the shoreline (r(2)=99%). Three case studies show hard coastal engineering solutions preserved Azorean coastal lifestyle and had little or no observed negative impacts on their environs. Although hard engineering is likely to remain a valuable and feasible coastal protection option, an inventory of São Miguels population distribution, surf breaks, bathymetry and coastal erosion rates showed the potential of using multifunctional artificial reefs as a soft engineering solution. These offshore submerged breakwaters offer coastal protection while providing additional benefits such as surfing amenity and beach widening. Consequently, findings of this work can inform other SI communities.

A Centurial Record of Beach Rotation

ABSTRACT Thomas, T., Phillips, M. R., and Williams A. T., 2013. A Centurial Record of Beach Rotation. Beach rotations are reliant on a bi-directional wave climate and headlands to impede alongshore sediment transport. This manifests itself in localised shoreline retreat or advance but does not lead to long term sediment loss or gain, as beaches often return to initial conditions in response to wave direction shifts and these changes are often seasonal. This paper assesses morphological changes of a headland embayed beach (Tenby, West Wales) over a 180 year period using GIS, cross shore profiles, and wave modelling. Within GIS maps, aerial photographs and direct field measurements identified two significant changes in beach orientation between the periods 1830–1919 and 1919–2009. Analysis of more recent data (1941–2009) showed that a statistically significant (R2 = 64%) negative phase relationship existed between the beach extremities and correlation changes revealed central region rotation. Results were consistent with wave modeling (RCPWave) that showed dominant waves emanate from southwest and cause long term longshore drift from south toward north. Subdominant waves emanating from the southeast cause counter-drift. In the decadal and seasonal term, negative phase relationships indicative of beach rotation were also established. Cross-correlation analysis between beach extremities showed that decadal term rotation occurred at timescales of less than one year. This was verified by seasonal term results, which showed with increased statistical significance that sediment exchange between headlands takes up to two months. Results have implications for coastal zone management and careful examination of these phenomena is required over both seasonal and longer timescales and should be considered in the development of new beach management strategies.

Multifunctional artificial reefs for small islands An evaluation of amenity and opportunity for São Miguel Island, the Azores

Multifunctional artificial reefs (MFARs) have been growing in popularity over the last decade. They are offshore submerged structures which provide coastal protection while also enhancing marine and recreational amenities such as surfing and beach widening. A feasibility study was undertaken for São Miguel Island (Azores) where island-wide general site-selection criteria and local site-specific parameters identified São Roque reef as a potential MFAR location. Expert knowledge addressed multidisciplinary aspects through semi-guided interviews, which provided evaluation criteria for the São Roque reef development. Wave changes before and after reef reprofiling were determined using the Regional Coastal Process WAVE propagation model (CEDAS/RCPWAVE). Results demonstrated additional coastal protection to the historic church and existing seawalls, and no adverse effects on the updrift São Roque and downdrift Pópulo Milicias beaches. Further simulation for an extended reef (30 m seaward) showed model sensitivity together with a greater reduction in approaching wave heights. This analysis suggested that the further seaward the reef is extended, the greater the coastal protection afforded. It also denoted longer, rideable surfing waves and greater substrate surface area for marine colonization, while conversely having an increasing effect on downdrift Pópulo Milicias beach, construction costs and footprint impact. An optimal solution will provide a balance to these advantages and disadvantages. A SWOT analysis showed the potential of capitalizing internal strengths and external opportunities to offset internal weaknesses and external threats. With global growing emphasis on the importance of incorporating amenity values into coastal protection works, this research informs alternative solutions for other small islands, especially similar small volcanic islands.