Rehabilitation of metropolitan beaches by local administrations in Catalonia: new trends in sustainable coastal management

The planning and management of coastal sites in Catalonia has been mainly concerned with rendering beaches functional for mass frequentation. This has caused serious problems for the beaches, including the alteration of dune formation processes and the destruction of beach vegetation and habitats. Municipal capacity to plan and manage beaches is theoretically very limited and relegated to the design of plans related to the maintenance of facilities for beach users. Nonetheless, a singular experience, led by a local council in the metropolitan area of Barcelona demonstrates the crucial role that a local administration can play in achieving a balance between habitat preservation and social use based on sustainable coastal management objectives, in spite of a restrictive legislation.     

Possible impact of sea-level rise on some habitat types at the Baltic coast of Denmark

According to estimates from the Danish Meteorological Institute global warming until 2080 may cause a relative sea-level rise in Danish waters of 33–46 cm. In the present paper the possible impact of a sea-level rise of this magnitude on coastal habitat types is discussed for three case studies, based on previous investigations of vegetation, topography and soil of localities at the Baltic coast of Denmark. The case studies include the following types of localities and habitats: (1) an off-shore barrier complex: sandy beach, sand dune, geolittoral, brackish, low-tidal meadow, reed bed; (2) a protected bay: geolittoral, brackish meadow, coastal grassland; (3) a dune area: mobile and fixed dune communities, and adjoining sea wall: coastal grassland. In the geolittoral meadow and coastal grassland habitats the sea-level rise is expected to cause a horizontal displacement of vegetation zones and a reduction in area, depending on accretion rate (sedimentation, peat formation), local topography and inland land-use. In the beach and sand dune habitats the sea-level rise is expected to cause a change in groundwater level, influencing slack vegetation, and a change in the erosion/accretion pattern, resulting in landward rebuilding of the mobile dune as well as in a more or less diffuse inland sand drift, causing destabilization of fixed dune vegetation.     

Flood-risk mapping for storm surge and tsunami at Cocos Bay (Manzanilla), Trinidad

Cocos Bay is a barrier beach under threat of marine erosion from the high energy environment of the Atlantic Ocean. This barrier beach borders the Ramsar listed Nariva Swamp, and helps maintain its delicate wetland ecosystem, however, ongoing coastal erosion at this beach threatens the longevity of this freshwater wetland. Due to the geographical location of Cocos Bay being exposed to Atlantic generated storm events and the low relief of the study area, there is a potential threat of storm surges breaching the barrier beach. Owing to the geological setting of the region (located in an active seismic province with earthquakes, volcanicity and landslides), there also exists the threat of tsunamis. This paper is a GIS simulation of the area extent of inundation and the affected infrastructure from such events. It utilizes a DEM and land-use to quantifying inundation areas, and the extent of vulnerability of various elements. The low relief of the barrier beach renders the area extremely vulnerable from events that trigger sea level increases. Simulations revealed that as little as a 1 m storm surge has the potential to disrupt the Nariva Swamp and threaten coastal infrastructure while higher storm surges and tsunamis have the potential to decimate the entire area. The flood-risk model generated indicates a very high vulnerability to storm surges, along the entire length of the coastline. These results have implications for future development and sustainable management of this ecologically sensitive area.     

A novelty coastal susceptibility assessment method: application to Valdelagrana area (SW Spain)

The main aim of this paper is to present a new methodology to determine coastal susceptibility to erosion and flooding processes by means of an index-based method. The proposed indices take into account physical parameters, such as dune and beach geomorphologic characteristics, shoreline evolution, local significant wave height and relative run-up. The coastal susceptibility has been estimated by elaboration of spatial input data into a GIS environment. The method has been tested in Valdelagrana area, a sandy spit located in SW Spain. The spit includes several morpho-sedimentary environments: sandy beach, discontinuous embryo dunes and foredunes, mud flats and wide areas of vegetated salt marshes. The Northernmost sector is densely urbanized whilst the rest is part of a natural protected area belonging to the Bahía de Cádiz Natural Park. The results obtained showed how the Southern part of the spit presented a high susceptibility due to an elevated erosion rate and the presence of low and discontinuous dune ridges.     

Predicting the Impact of Sea-Level Rise on Caribbean Sea Turtle Nesting Habitat

Abstract:  The projected rise in sea level is likely to increase the vulnerability of coastal zones in the Caribbean, which are already under pressure from a combination of anthropogenic activities and natural processes. One of the major effects will be a loss of beach habitat, which provides nesting sites for endangered sea turtles. To assess the potential impacts of sea-level rise on sea turtle nesting habitat, we used beach profile measurements of turtle nesting beaches on Bonaire, Netherlands Antilles, to develop elevation models of individual beaches in a geographic information system. These models were then used to quantify areas of beach vulnerable to three different scenarios of a rise in sea level. Physical characteristics of the beaches were also recorded and related to beach vulnerability, flooding, and nesting frequency. Beaches varied in physical characteristics and therefore in their vulnerability to flooding. Up to 32% of the total current beach area could be lost with a 0.5-m rise in sea level, with lower, narrower beaches being the most vulnerable. Vulnerability varied with land use adjacent to the beach. These predictions about loss of nesting habitat have important implications for turtle populations in the region.     

Inventory and conservation assessment for the management of coastal dunes,Veneto coasts,Italy

Management of coastal dunes on developed coasts could effectively take advantage of comprehensive and multitemporal georeferenced data collection, which offers the possibility to relate dune data with the natural and cultural characteristics of the beach and hinterland. The recent implementation of a coastal management geodatabase for the Veneto region provides the opportunity for improving knowledge on coastal dunes on developed littoral as well as a basis for appropriate future coastal planning in the study area. The geodatabase gathers data concerning different physical, evolutionary and human aspects of the coastal zone, with a special focus on coastal dunes. Established foredunes, human-altered dunes and relict dunes are irregularly distributed along 59 km, 38% of the entire coastal length. Their distribution and characteristics are the result of favourable natural conditions as well as long-lasting tourism exploitation (evaluated through an index of Land Use Pressure) and fragmentary and diversified uses of beaches (evaluated through an index of Tourism Pressure on the beach). At the same time, beach/dune nourishment intervention allowed the presence of artificial or sand fenced dunes along 17 km of coast. High dune elevation up to 8–10 m is promoted by the onshore exposition of the beach to dominant wind (from ENE), by stable-to-slowly negative sedimentary budget or by the re-activation of high relict foredunes in the case of shoreline retreat associated with strong negative budget. Present sedimentary budget (evaluated through the code ASPE – Accretion, Stable, Precarious, Erosive) is the tool used for dividing coasts in sedimentary compartments or cells. Past and present sedimentary budget and different human responses to erosive cases (hard and soft interventions) give the foredunes different means to form, grow, survive and evolve over time. The assessment of Human Impact and Active Management Practices on the dunes allows a first evaluation of the Management Effectiveness, which shows strong shortcomings for 81% of the dunes. The great variability of beach usage, human impact and management practises on the different dune stretches highlight the lack of effective and systematic management actions being correctly scheduled and performed.     

Modelling of coastal vulnerability in the stretch between the beaches of Porto de Mós and Falésia, Algarve (Portugal)

Coastal systems are characterized by high geophysical and biophysical sensitivity as being their massive occupation a serious issue concerning their self-regulation. Worldwide coastal areas are exposed to problems such as coastal erosion, degradation and destruction of marine habitats, pollution and rising sea level. Thus, it is crucial to design models of coastal vulnerability assessment to ensure a better management of coastal areas. This study characterizes the vulnerability of the coastal stretch between the beaches of Porto de Mós and Falésia in the Algarve, corresponding to 52?km of the south coast of Portugal. The expansion of urban areas was modelled using a Cellular Automata (CA) based approach. Results show that 65% of the coastal stretch has high and very high vulnerability caused by both physical and human factors. Results further indicate that urban growth may interfere with the natural evolution of the coastal geomorphology. The scenario of urban expansion for the year 2015 highlights the need to develop effective urban planning processes to ensure a correct balance between the geophysical resilience of coastal systems and the promotion of the coastal sector as a strategic asset for the regional and national economy.     

The assessment of the coastal vulnerability and exposure degree of Gran Canaria Island (Spain) with a focus on the coastal risk of Las Canteras Beach in Las Palmas de Gran Canaria

The Coastal Vulnerability and Exposure Degree (CVED) of the Gran Canaria Island and the coastal risk of Playa de Las Canteras (Las Palmas de G.C.) have been assessed by means of a GIS analysis. The evaluation of coastal vulnerability (H) has been performed by using two different levels of analysis: the first one regarding the entire Island (Coastal Vulnerability Index method - CVI), the second one regarding specifically Las Canteras Beach, selected for its socio-economic importance (Coastal Vulnerability Assessment method - CVA). The application of the CVI method, based on geologic-geomorphologic and meteomarine data easily available, has allowed the regional scale assessment of coastal vulnerability (H) along the Gran Canaria coastline and, therefore, the individuation of more critical coast stretches deserving further analysis. The application of the CVA method, based on more specific morphologic-sedimentary beach features that allow to consider both the beach retreat due to storm surge and the coastal inundation due to run-up on the beach, has provided a large scale detail on the coastal vulnerability of Las Canteras Beach. Socio-economic and damage indexes have been determined for the 15 coastal municipalities included in the study area and, by means of the resulting matrix product, the degree of exposure (E_x) along the Gran Canaria coast has been assessed. Finally, the combination of coastal vulnerability and exposure levels has allowed to obtain the Coastal Vulnerability and Exposure Degree (CVED) for the entire Island and the risk levels that characterize specifically Las Canteras Beach. Major results in terms of CVED highlight prevailing low vulnerability and exposure levels along the western coast, and overall high vulnerability and exposure levels along the eastern coast, from Las Palmas de G.C. to San Bartolomé de Tirajana. The focus made on Playa de Las Canteras has allowed to identify the areas characterized by medium and high risk levels that represent approximately one third (940 m) of the entire beach and are located in its central part. The used two-level analysis approach has proved its efficiency by highlighting the degree of coastal vulnerability along the study coast and, especially, more critical coast stretches (CVI method) such as the Playa de Las Canteras that can be successfully analysed with the CVA approach allowing for a large-scale assessment of risk aspects, essential for a correct definition of priority management strategies. Results obtained with the present study, along with the awareness of the increasing phenomena of coastal erosion and marine flooding arising on the mid-long term due to the effects of global climate change, highlight the need for the competent public administrations of Gran Canaria to develop a strategic approach to coastal management and sustainable development that considers as a whole socio-economic values and natural resources, coastal vulnerability and exposure degree, and risk aspects.     

Development of new dunes in the Dutch Delta: nature compensation and ‘building with nature’

A new dune area was constructed by beach and foreshore nourishments along the Delfland Coast in the southwestern Netherlands. The new area is intended to be a compensation for losses of existing high quality dunes in nearby areas, due to the use/construction of Maasvlakte 2, the new harbour extension of Rotterdam opening in 2013. The target habitats for compensation include dry grey dunes and moist dune valley grassland. Due to the habitat type, the nourished material had to have a special character. The nourishment was carried out according to a special design and initial development of the new area had to follow certain pathways. In order to meet the compensation requirements in time. Careful monitoring is done to assess whether development of the new habitat is taking place in the direction of the desired target habitats. This paper reports on the construction of the new area and on the first years of development and monitoring. The monitoring mainly concerns development of the abiotic landscape elements, geomorphology, groundwater and soils. The lessons learned from this area are discussed in the light of the development of other recent young nature areas in the sandy Dutch delta coast. This gives new insights for coastal management in general in the context of building with nature.     

Physical damage to coastal dunes and ecological impacts caused by vehicle tracks associated with beach camping on sandy shores: a case study from Fraser Island,Australia

As coastal populations expand, demands for recreational opportunities on beaches and coastal dunes grow correspondingly. Although dunes are known to be sensitive to direct human disturbance and provide irreplaceable ecosystem services (e.g. erosion control, critical habitat and nesting sites), dunes serve as campsites for large numbers of people (∼90,000 p.a.) on the ocean-exposed shores of Fraser Island, Australia. Campsites are located in the established dunes and can only be accessed with 4WD vehicles along tracks cut directly from the beach through the foredunes. Here we quantified the extent of physical damage to foredunes caused by this practice, and tested whether human-induced physical changes to foredunes translate into biological effects. Of the 124 km of ocean-exposed beaches, 122 km (98%) are open to vehicles driven on the beaches, and camping zones cover 28.7 km or 23% of the dunes. A total of 235 vehicle tracks are cut across the foredunes at an average density of eight tracks per km of beach. These tracks have effectively destroyed one-fifth (20.2%) of the dune front in camping zones, deeply incising the dune-beach interface. There is evidence of accelerated erosion and shoreline retreat centred around vehicle tracks, resulting in a “scalloping” of the shoreline. No dune vegetation remains in the tracks and the abundance of ghost crabs (Ocypode spp.) is significantly reduced compared with the abutting dunes. Because current levels of environmental change caused by dune camping may not be compatible with the sustainable use of coastal resources and conservation obligations for the island (listed as a World Heritage Area and gazetted as a National Park), restoration and mitigation interventions are critical. These will require spatial prioritisation of effort, and we present a multi-criteria ranking method, based on quantitative measures of environmental damage and ecological attributes, to objectively target rehabilitation and conservation measures. Ultimately, coastal management needs to develop and implement strategies that reconcile demands for human recreation, including beach camping, with conservation of coastal dune ecosystems.     

Current status and future restoration of coastal dune systems on the Catalan shoreline (Spain,NW Mediterranean Sea)

Coastal dunes are an essential part of beach-dune systems. Dunes systems have their own intrinsic values and provide a range of goods and services, including the protection of tangible goods located on the shoreline affected by waves, storms, and sea erosion. Dunes also act as repositories of biodiversity that have their exclusive habitat in dune communities, and the aesthetic value of dune landscapes derived from unique plant communities and landforms is also of great importance. Nevertheless, dune systems on developed coasts suffered a drastic decline in geomorphological and ecological quality throughout the last century. Catalonia (Spain, NW Mediterranean Sea) is no exception, and the coastal dune systems which were present in the early 20th century have now disappeared due to urbanization. The regeneration of dune systems is of crucial importance in this context. The aim of this study is to assess the current status of dune systems in Catalonia in order to determine their future prospects based on beach characteristics, those beaches likely to host dunes being determined according to their width and sediment type. The results of our study show that nowadays most dune systems in Catalonia are not developed due to human pressure on the beaches. Only those beaches located in the natural protected areas in Roses Bay, Baix Ter Bay, the Llobregat Delta, and especially the Ebro Delta, have the right characteristics to host well-developed dune systems. That said, 30% of sandy beaches in Catalonia have a width of over 35 metres; wide enough to host well-developed dune systems if appropriate integrated beach management is applied. The methodology used in this research also provide a tool to assess which are the beaches that can host dunes on other developed shores in the Mediterranean area.     

Contrasting ecology of prograding coastal dunes on the northwest coast of Ireland

This paper examines the influence of dune morphological evolution on plant species diversity and composition on the Magheramore dune system, Donegal, north-west Ireland. It aims to demonstrate the need for understanding of local geomorphological factors and their affect on ecological processes for the enhanced conservation management of coastal dunes. Vegetation surveys and cluster analysis of species associations, in combination with GIS analysis focused on two prograding dune sites within the Magheramore system. Contrasting geomorphic evolution over similar timescales has imposed site-specific environmental conditions that have had a direct impact on the range of plant species communities present. Cluster analysis revealed 5 main species community types that defined specific dune habitats, the organisation of which is strongly influenced by geomorphic evolution. This study demonstrates the importance of geomorphic evolution and morphological heterogeneity in habitat and species diversity.     

The role of community-based organization in the promotion of disaster preparedness at the community level: a case study of a coastal town in the Kochi Prefecture of the Shikoku Region, Japan

The Japanese rural coastal areas are inherently vulnerable to typhoons and tsunamis. Their vulnerability has been further increasing recently, in part due to social factors such as the aging of society and depopulation. Following the Kobe earthquake of 1995, the Japanese government has promoted the Voluntary Disaster Preparedness Organization (VDPO) to build communities that are more sustainable and resilient to natural disasters. However, studies indicate that some VDPO activity has stagnated. The present study focuses on a rural coastal area in Japan and examines whether VDPO impacts residents’ awareness of disaster preparedness and also examines ties among the community. The study relies on a questionnaire survey. It reveals that VDPO contributes to improving both awareness of disaster preparedness and ties in the community.     

Coastal dune development and morphological changes along the littorals of Garigliano,Italy, and Elis,Greece, during the Holocene

Geomorphological and sedimentological studies were carried out along the Garigliano and Elis littorals with the aim to highlight if similar geoenvironmental features are controlled by same coastal processes. Actually, both sites are in Mediterranean climate regions very far each other, modeled by western winds and storms, characterized by wide sandy coastal dunes parallel to the present shoreline, with abundant pumices, and locally anthropized. The Garigliano littoral is characterized by Holocene dune and Pleistocene aeolian deposits. The beach is bounded landwards by a dune system emplaced during the Holocene. Geoarchaeological surveys highlighted the presence of a Roman road which cut the dune, with age older than Graeco-Roman Period. Since the end of the 1950’s, strong littoral retreat affected the beach-dune system, partly due to human activity. The coastland of Elis is characterized by Quaternary marine deposits. Three significant morphogenetic phases occurred during the Holocene. During the last phase, from Graeco-Roman Period to current, shoreline retreat and deposition of aeolian sands occurred. Geoarchaeological evidences suggest that this phase is related to a sea-level lowstand followed by a slow sea-level rise up to the present position, and by humid-temperate climate. Geomorphological surveys of the dunes of Garigliano and Elis, each other compared, suggest that the main phases of their development are related to the effects of climatic conditions, sea-level changes, and secondly to the recent anthropization. The coarse pumices found on both beaches of Campania and Peloponnese regions show the same mineralogical and petrographic features, so we assumed that they likely originated from the Aeolian Arc, southern Italy, which have same composition. These pumices reached the studied coasts by flotation, under the influence of winds and marine surface currents from the southwest-southeast and northwest-west respectively, participating to local coastal processes and representing a good geoindicator of long-distance drift. Precisely for these morphologically converging aspects, such distant sites have been selected and compared.     

Dynamic preservation of the coastline in the Netherlands

In 1990, the Government and Parliament of the Netherlands decided on a new national policy for coastal defence. To ensure the enduring safety of the low-lying polders as well as the sustainable preservation of the coastal dunes, it was decided to maintain the coastline in its 1990 position. The main method for coastline preservation in the Netherlands is beach nourishment. Since 1991, approximately 7 million m³ of sand is added to the Dutch beaches annually. From an evaluation study of sand nourishment projects it is concluded that nourishment is an effective and efficient method to preserve the coastline. The evaluation study also proves that nourishment projects should be ‘tailor-made’, taking the local morphological and hydraulic conditions into account. The first results of an experimental shoreface nourishment are discussed. The choice for nourishment as the principal method to combat erosion is well in line with the intention to restore the natural dynamics of the dune-coast in the Netherlands. The key probably is a less strict policy with regard to the maintenance of the foredunes. Plans for the development of typical coastal features such as slufters^*, wash-overs, blow-outs and mobile dunes are currently under discussion. A slufter is a breakthrough in the first dune-ridge whereby the sea invades former dune slacks or beach plains situated behind the duneridge. In this way a tidal marsh is formed within the dune zone.     

Ecohydrological studies of dune slack vegetation at Kenfig dunes,South Wales,UK

Dune slacks are important coastal sand dune habitats and seasonal changes in water levels within dune aquifers control both their formation and the specific hydrological conditions which then govern the floristic composition of their characteristic plant communities. Kenfig Dunes National Nature Reserve is one of the largest dune sites in South Wales and Southern Britain. It supports an exceptional range of dune slack communities, including most of those recognised in the British National Vegetation Classification scheme. Detailed studies of the vegetation ecology and hydrology of dune slacks reveal the important influence of hydrological variables in controlling the composition of dune slack vegetation and also valuable information on water table profile and the key factors governing the annual hydrological budget of the dune system aquifer.     

Shoreline management and its implications for coastal processes in the eastern part of the Rhône delta

The coastal fringe of the eastern part of the Rhône delta is a large area where activities related to ecological and economical interests have increased since the beginning of the century, including the salt industry of theCompagnie des Salins du Midi et des Salines de l’Est, the industrial complex ofFos-sur-Mer, tourism managed by the local authorities ofPort-Saint-Louis andArles, and dune restoration of the La Gracieuse spit undertaken by thePort Autonome de Marseille. The vulnerability of the area for changes brought about by these activities is linked to the extent of several coastal changes, whereas these changes are related to the physical functioning of the coastal fringe, such as coastal processes, but also to external components such as relative sea-level rise, subsidence, reduction of sediment input, human impact, etc. For many decades, coastline ‘protection’ in the eastern part of the Rhône delta has been undertaken to withstand erosional processes that offset beaches and retreat of the littoral. The use of different engineering structures illustrates the heterogeneity and differences in age of the various management policies. At the eastern side of the Rhône, thePort Autonome de Marseille, dealing with management, has opted for soft engineering structures using fences for dune restoration on the La Gracieuse spit. At the western side of the mouth, theCompagnie des Salins du Midi et des Salines de l’Est has been using hard engineering structures to combat erosion (rocks, groins, tetrapods, etc.). A brief assessment of the management efficiency is presented, including an analysis of the data collected concerning the survey of the zones where the structures were built. Their varying efficiency shows the important role played by the sediment supply to the littoral (solid river discharge) and the coastal hydro-sedimentary processes. In the eastern part of the Rhône river the success of the dune restoration is mainly due to the important sediment supply transported in this area by eastern drift currents. At the western part of the mouth, the decrease of sediment supply linked to erosional processes in the shallow off-shore beach has made the structures more vulnerable, and therefore, the activities of the salt industry. For this last threatened zone, three management scenarios are discussed by taking into account economical, physical and ecological parameters.     

Environmental assessment of Kuwait Bay: an integrated approach

Kuwait Bay is an imperative characteristic of the State of Kuwait. It has a number of major activities existing around it, including, business, industrial and recreational ones. The phase of construction and development of projects, and their resulting pollution have led to major change in the features of the area. The purpose of this research is to serve as a managing tool for decision-making through the environmental assessment of Kuwait Bay. Due to the multiplicities and diversities of the man-made activities and the natural environmental setting of the bay, the impacts are out looked on a holistic approach rather than on a single approach. The methodology of assessment including, sampling and analysis of water and sediment, statistical analysis, as well as application of the Rapid Impact Assessment Matrix (RAIM) in order to analysis the impacts in an integrated approach. The southern areas of the bay are the main sources of pollution that distributed northward to cover the central region of the bay. Sulaibikhat Bay (South-West sector of the bay) is the most vulnerable area due to its exposure to anthropogenic activities such as reclamations, sewage inflow and other activities. The area near Shuwaikh Port is suffering due to reclamation processes. The northern and north-west sectors suffer from coastal erosion as well as from pollutants arriving via Shatt Al Arab.     

Wave hydrodynamics around a multi-functional artificial reef at Leirosa

This paper describes an application of the Boussinesq-type COULWAVE model to study the wave hydrodynamics in the vicinity of a multi-functional artificial reef (MFAR). This reef is under investigation and consists of a supplementary protection solution for the Leirosa sand dune system located at South of Figueira da Foz, on the Portuguese West coast. Such installation near the coastline is expected to contribute to enhance the surfing conditions in the area, protect the sand dune system in the surroundings of Leirosa beach, and increase its environmental value. Numerical calculations with the COULWAVE model were performed for four test cases, considering two reef geometries (differing in the reef angle) and two incident wave conditions (storm condition and a common wave condition). Comparisons between the results obtained, in terms of wave heights and breaking line positions allow us to assess the influence of the reef on the hydrodynamics near the beach and around the reef. Moreover, the reef performance was analysed in terms of surfability and coastal protection. The surfability parameters (breaker height, Iribarren number and peel angle) were calculated for each test case using the numerical wave heights, wave directions and wave breaking positions. Comparisons of parameters allow characterizing the most appropriate configuration of the reef to improve the surfing conditions in the study area. A methodology based on numerical free surface elevations and horizontal velocity components was developed to calculate wave directions, since this is not a direct output of the COULWAVE model. Concerning coastal protection, analyses of the mean currents around the reef were used together with observations of the velocity cells near the shoreline as an indication of the sediment transport.