Coastal Processes

An intensive sampling program of physical and chemical parameters at the mouth of Vassova lagoon (Northern Greece) during 4 separate tidal cycles is described. The study aims at understanding the tidal circulation and estimating the instantaneous and residual fluxes of water, salt and nutrients through the entrance canal of this micro-tidal lagoon. Results showed that tidal flood exceeded in duration tidal ebb, under spring and neap tidal conditions. Ebb tidal currents were recorded higher than flood currents, especially under neap tidal conditions. Unsteady flow characterized the temporal variation of longitudinal and lateral velocity, inducing a rightward deflection on flood or ebb flow. The intra-tidal variability of dissolved inorganic nitrogen showed seasonal dependence, with higher values during September, October and early March, and lower during the late March period. Residual current and flux analysis into a Eulerian and a mass transport Stokes drift mechanism illustrated t...

ا خل ص
ريغت دعي لاح خانملا ي ًا  تايدحتلا مهأ دحأ ةيعيبطلا يتلا هجاوت لاعلا .م  دقف  تمهسأ لماوع
ةدع يف ثودح  تاريغت ةيخانم  نابوذ اهنع جتن تايمك ةلئاه نم ديلجلا ؛  يلاتلابو عافترا
طسوتم بوسنم حطس  ،رحبلا وهو ام  قلقي  ةيلحاسلا لودلا تقولا يف لا يلاح .    اذه نمو
  ثحابلا راتخا ،قلطنملا  تاريغتلا رثلأ ةلاح ةساردك لاكملا ةنيدم  ايجولوفروم ىلع ةيخانملا
( يلاوح دتمي يذلا ،اهلحاس 63 تفدهو .ندع جيلخ رحب ىلع مك )  هذه ةقرولا  ىلإ  مادختسا
  تاينقت مظن تامولعملا راعشتسلااو ةيفارغجلا دعب نع عضول روصت يلبقتسم  لكشل  لحاس
يف لاكملا ةنيدم ةلاح ةدايز بوسنم حطس رحبلا  نم تحو دحاو رتم ةسمخ ى  ةفرعمو ،راتمأ
.تاناضيفلاو رحبلا هايمب رمغلل ةضرعملا ءايحلأا  نم نيبتو    للاخ  تانايبل يناكملا ليلحتلا
( ةيمقرلا تاعافترل اا DEM ريغت فرع لاكملا ةنيدم لحاس نأ )  ًا  ةرتفلا للاخ 1973 - 
ويام 2019  ( غلب 47 ريغت لحاسلا طخ فرعيس امك ،% )  ًا ظوحلم  ًا  عافترا ةدايز ةلاح يف
  رحبلا ةيجولويجلا ةينبلا ةعيبط بسح ريغتلا اذه توافتيو ،راتمأ ةسمخ ىتحو ٍ دحاو رتم نم
ءاقتلا قطانم يف اهرثكأ تزكرت ،رحبلا هايمب رمغلل نكامأ ضرعتتسو ،لحاسلل سيراضتلاو
.هَّ وفو ،لاكملا روخو ،شيوبو ،نايرلا ءايحأ نم ٍ لك يف ةيدولأا هايمب رحبلا هايم

Pour caractériser le risque de submersion marine, il est très important d'avoir une connaissance précise des lois de distribution des niveaux d'eau marins, et plus particulièrement des niveaux d'eau extrêmes. En effet ce sont eux qui sont à l'origine des conséquences les plus dramatiques. Le programme de recherche mené au cours de cette thèse a été financé par le Ministère de l'Écologie, du Développement Durable et de l'Énergie. L'objectif final est de fournir des valeurs de référence de niveau d'eau marin le long des côtes françaises, par le biais d'une méthode d'analyse statistique des extrêmes. Ces niveaux comprennent les trois composantes suivantes : la marée, la surcote météorologique et le wave set-up. Le principe de base utilisé est le suivant : une analyse statistique est effectuée aux ports où la donnée marégraphique est disponible, puis le résultat est interpolé entre les ports. Différentes approches sont testées. Les points suivants...

Pour caracteriser le risque de submersion marine, il est tres important d'avoir une connaissance precise des lois de distribution des niveaux d'eau marins, et plus particulierement des niveaux d'eau extremes. En effet ce sont eux qui sont a l'origine des consequences les plus dramatiques. Le programme de recherche mene au cours de cette these a ete finance par le Ministere de l'Ecologie, du Developpement Durable et de l'Energie. L'objectif final est de fournir des valeurs de reference de niveau d'eau marin le long des cotes francaises, par le biais d'une methode d'analyse statistique des extremes. Ces niveaux comprennent les trois composantes suivantes : la maree, la surcote meteorologique et le wave set-up. Le principe de base utilise est le suivant : une analyse statistique est effectuee aux ports ou la donnee maregraphique est disponible, puis le resultat est interpole entre les ports. Differentes approches sont testees. Les points suivants...

A camada limite planetária (CLP) na região de Iperó-SP é estudada através de simulações numéricas utilizando um modelo unidimensional com fechamento de segunda ordem. Os resultados indicam que os fluxos verticais turbulentos, em resposta ao aquecimento solar, de calor sensível e latente têm valores máximos próximo à superfície decrescendo linearmente com a altura, favorecendo assim os transportes de calor e umidade para os níveis mais altos da atmosfera. No período noturno a turbulência térmica praticamente cessa e consequentemente os fluxos turbulentos são pequenos em toda extensão vertical da CLP. Em resposta a isto, os perfis verticais médios de temperatura e umidade são melhor simulados durante o dia. Por outro lado, os fluxos em superfície e o saldo de radiação simulados estão em quase perfeita concordância com os observados durante todo o período, e o ciclo diurno da temperatura do ar próximo à superfície é satisfatoriamente simulado.

The expansion of the Popoh PPI in Popoh Village, Tulungagung, East Java affects the movement of currents and waves in the vicinity. The purpose of this study was to analysis sediments and the pattern of coastline changes and to elaborate these using wave modelling based around the expansion of the Fish Landing Port Popoh. The methods used in this research were sieve analysis, remote sensing and GIS for processing Sentinel-2 imagery, and hydrodynamic modeling using DHI MIKE 21. Sediment sampling was carried out based on a purposive sampling method, with 10 points spread over land and water using a sediment grab. The findings of the study showed that there was a fairly large accretion from 2015 to 2021, with sand and clay sediment types. The accretion process dominated the abrasion process at Popoh Beach. In the period 2015 to 2018, the area of accretion was 17.78 hectares and, in the period 2018 to 2021, the area of accretion was 9.32 hectares, so that for 6 years there was an accretion of 18.79 hectares. The average wave energy was 1.5 kW/m per year on eroded beaches with sandy sediments.

The coastal region is characterized by dynamic changes in its coastline, which can be attributed to various factors. However, the main causes of change along the Gresik coast have yet to be thoroughly studied. Therefore, this research aims to examine the patterns of coastline change along the Gresik coast around the Madura Strait and the influence of wind-generated waves on them. Specifically, the study focuses on four coastal zones: Ujung Pangkah, Sidayu, Bungah, and Manyar districts. The research utilizes satellite imagery and geographic information systems (GIS) as well as methods for calculating ocean waves to analyze the coastline change patterns. The study also examines the impact of ocean wave energy on coastal abrasion and accretion. The findings revealed that the accretion rate in the study area was higher than the erosion rate. The accretion in the coastal area of Gresik is attributed to the flow of the Bengawan Solo River, which carries sediment from upstream. The accretion and abrasion areas for the entire period from 2002 to 2019 were 1063.16 ha and 425.23 ha, respectively. The study also found that the mangrove areas exhibit a higher rate of accretion than abrasion, indicating their potential as a reliable indicator of the effects of sea level rise resulting from global warming. This study revealed that the northern part of Ujung Pangkah District and Bungah District experienced the highest abrasion patterns, whereas no abrasion was observed in Sidayu District. Between 2002 and 2019, the abrasion areas in Ujung Pangkah and Bungah districts totaled 243.96 ha and 178.29 ha, respectively. Windgenerated waves were likely the primary cause of the abrasion in these areas, though other factors may also have contributed to coastline changes. It is essential to consider these factors for effective coastal management in the region.

La erosión litoral ha sido la tendencia histórica dominante a lo largo de los aproximadamente 145 km de línea de costa entre las ciudades de Arboletes y Turbo (sur del Litoral Caribe colombiano). En las cuatro últimas décadas ocurrieron retrocesos de la línea de costa del orden de los 50-100m en varios sectores (Uveros, Damaquiel, Zapata, Turbo), y de hasta 1.6 km en el área Punta Rey-Arboletes, en la cual las pérdidas de terrenos suman más de 4.5 km2 y la erosión alcanzó tasas máximas de hasta 40m/año. La síntesis de la información disponible sugiere que la “susceptibilidad” generalizada a la erosión podría ser la respuesta a ascensos relativos del nivel del mar, asociados a la tectónica regional, a los efectos del diapirismo de lodos y a la hidroisostacia, entre otros posibles factores. En los sectores más críticos (Arboletes y Turbo), las tendencias erosivas naturales fueron aceleradas por intervenciones humanas como la desviación del río Turbo, la extracción intensiva de materiales de playa y el manejo inadecuado (o no manejo) de las aguas lluvias y residuales. El costo actualizado de las 155 obras de defensa (espolones, barreras y muros de contención que totalizan 6.2 km de longitud y un volumen de materiales de 37.000m3) construidas hasta agosto del 2000 se calcula en alrededor de los $ Col 10.000 millones. Con muy pocas excepciones, los espolones perpendiculares a las playas no han recuperado arenas y más bien se han convertido en generadores de nuevos problemas en los sectores adyacentes. A corto plazo, la erosión litoral entre Arboletes y Turbo es causada tanto por factores marinos como por procesos de erosión subaérea y es función en buena parte de las litologías poco resistentes de las terrazas y acantilados, compuestos en su mayoría por lodolitas fracturadas y meteorizadas (con buzamientos o planos de debilidad inclinados hacia el mar) y por sedimentos finos no consolidados, fácilmente licuables: ambas condiciones facilitan la ocurrencia de deslizamientos, caídas de rocas y flujos de lodo que determinan retrocesos rápidos (3 a 4 metros) del contorno litoral, sobre todo en los primeros 15 días de la transición verano-invierno (abril) y durante los “mares de leva” (periodos de oleajes fuertes). El caso de la erosión litoral entre Turbo y Arboletes ilustra claramente cómo las tendencias erosivas naturales pueden intensificarse fuertemente por intervenciones humanas (incluyendo las defensas ingenieriles) y la necesidad urgente de coordinar esfuerzos para controlar o mitigar con eficiencia las pérdidas de terrenos litorales.

In this paper, the profiles of three artificial coarse-grained beaches located at Marina di Pisa (Tuscany, Italy) were monitored from April 2008 to May 2009 in order to define the response of the beaches to major storms that occurred during the study. Two beaches are similar, the third differs in length and in the level of protection, being less than half the length of the others and devoid of an offshore submerged breakwater. The work was achieved by means of accurate topographic surveys intended to reconstruct the beach profile from the backshore up to the foreshore-upper shoreface transition (step). The surveys were performed with an RTK-GPS instrument, which provided extremely precise recording of the beach. The most significant features of the beaches were tracked during each survey; in particular, the landward foot of the storm berm, the crest of the storm berm, the coastline, and the step crest were monitored. Five cross-shore transects were traced on each beach. Along these transects, any meaningful slope change was recorded to obtain accurate sections of the beach. The field datasets were processed with AutoCAD software to compare the beach profile evolution during the year-long research. The results showed a comparable evolution of the twin beaches: the resulting storm berm retreat of about 15 to 19 m is a remarkable feature considering the coarse grain size and the offshore protection. Due to the absence of the breakwater, the third beach was characterized by even higher values of recession (over 20 m), and showed hints of wave reflection-related processes after the huge, steep storm berm had been formed and grown after the high energy events. These processes were not as evident on the twin beaches. These results underline the different response of three similar protection schemes, and the importance that frequent monitoring of the beach morphology holds when it comes to coastal management issues.

The existing theory for shore‐transverse rhythmic sand bars relies on morphodynamic instabilities involving the wave‐driven longshore current and rip currents. Intriguingly, transverse finger bars are common on coasts with sediment excess, something not related to those currents. Here we show that, if the actual beach profile is above the equilibrium profile, cross‐shore transport can induce an instability triggered by onshore transport together with wave refraction by the emerging bars. We use a numerical model that filters out the dynamics associated to longshore and rip currents but includes a simplified version of cross‐shore transport and is able to reproduce the formation of shore‐transverse bars. The alongshore spacing scales with the wavelength of the incident waves and the cross‐shore extent is approximately equal to the distance from shore to the depth of closure. The modeled bars compare qualitatively well with observations at El Trabucador back‐barrier beach (Ebro delta,...

We investigate the rapidly changing equilibrium between the momentum sources and sinks during the passage of a two-peak storm over the Catalan inner-shelf (NW Mediterranean Sea). Velocity measurements at 24 m water depth are taken as representative of the inner shelf, and the cross-shelf variability is explored with additional measurements at 50 m water depth. At 24 m, as the storm-related wind stress accelerated the flow, velocity increased throughout the water column, resulting in bottom stress starting to become important. The sea level also responded, with the pressure gradient force opposing the wind stress. In particular, during the second wind pulse, there were rapid oscillations in the acceleration and advective terms, apparently reflecting the incapacity of the bottom stress to dissipate the high kinetic energy of the system. The Coriolis and wave induced terms (via radiation stresses) were less important in the momentum balance. The frictional adjustment time scale was aro...

Coastal Blue Carbon ecosystems like seagrass meadows are foundation habitats with a capacity to sequester and store organic carbon in their sediments, and their protection and restoration may thereby support climate change mitigation while also supporting biodiversity and many other ecosystem functions. However, seagrass ecosystems are being lost due to human activities, disease and, in some regions, climate change, which may trigger the release of stored carbon into the atmosphere. Yet, we do not fully understand how global change-induced seagrass loss influences sedimentary carbon dynamics. What is even less clear is whether seagrass loss may also result in tipping points, i.e., abrupt and difficultto-reverse shifts, in carbon flux dynamics turning seagrass ecosystems from net carbon sinks to net carbon sources. Here, we propose that conceptual mechanistic models of coupled ecological and biogeochemical dynamics can help to study the effects of major stressors on seagrass meadows and associated carbon fluxes. We then illustrate one case of such a conceptual model that focuses on anthropogenic induced mortality by physical stress as an example. Our perspective highlights how a modeling approach for understanding the response of carbon fluxes in seagrass ecosystems to global change stressors may be useful in informing coastal seagrass management towards climate change mitigation actions.

Change is inherent in coastal systems, which are amongst the most dynamic ones on Earth. Increasing anthropogenic pressure on coastal zones interferes with natural coastal dynamics and can cause ecosystem imbalances that render the zones less stable. Furthermore, human occupation of coastal zones often requires an uncharacteristic degree of stability for these inherently dynamic coastal systems. Coastal management teams face multifaceted challenges in protecting, rehabilitating and conserving coastal systems. Diverse monitoring schemes and modelling tools have been developed to address these challenges. In this article, we explore various perspectives: the integration of biophysical, ecological and social components; the uncertainties of diverse data sources; and the development of flexible coastal interventions. We propose general criteria and guidance for an Ecosystem-based Management (EbM) to coastal management, which aims primarily at adaptation to global change and uncertainties, and to managing and integrating social aspects and biophysical components based on the flows of energy and matter.

The aim of this project was to build a greater understanding of how "flashy" river networks link the terrestrial and coastal marine (fjordic) environments and facilitate the transfer of sediment and carbon. Through precise mapping of the River Strontian (Fig. ) channel we have created a 1D hydrological model (Fig. ) in HEC-RAS which is capable of modeling basic sediment transport. Through a combination of this model and data collected from the sediment (e.g. % Carbon and Stable Isotope values) we will gain a greater understanding of the mechanisms of sediment and carbon transport in these "flashy" systems. Despite the ecological, biological, and economic importance of coastal oceans, the magnitude and long term stability of coastal carbon stocks are poorly quantified in comparison to many national terrestrial (e.g. Chapman et al.,2009) carbon stocks. A recently commissioned report by Scottish Natural Heritage on 'blue carbon' noted that "coastal and offshore sediments are the main repositories for carbon in Scotland's marine environment" . There is still considerable uncertainty over the amount of carbon sequestered in coastal sediments and what drives the transfer of carbon from the terrestrial to the marine environment, both in Scotland and elsewhere in the world.

In an ideal situation a healthy and stable coastal ecosystem is very supportive of traditional shore based small scale fisheries. This health in turn is maintained by the desirable linkages with the riverine systems that supply sediments and nutrients to the coasts. Kerala's unique geography maintained this linkage between the coast and the mountains with network of forty one west flowing rivers and the chain of backwaters with dynamic estuaries. However, this unique feature of Kerala's coast has undergone rapid changes in the recent past. Since the Third Five Year Plan(1961-1966), Government of Kerala emphasized creation of infrastructure facilities such as fishing harbours, fish landing centers, fisheries roads, fisheries dispensaries, guide lights, community resource centres, fisheries research institutes and schools for the coastal fishing communities 1 . Today it is estimated that currently 63 percent of its coastline is tampered with engineering structures such as sea-...

In the present work, an attempt has been made to address the groundwater quality issue of Ajmer-Pushkar railway line region in post-monsoon season. Physico-chemical characterization of groundwater in the study area has been carried out as per national and international standards. The study revealed in groundwater contamination post-monsoon season. Some samples were found to have higher contents of Ca, TDS, Na and F than the limits prescribed by BIS, and WHO.

Baja California Peninsula is the westernmost tectonic province of Mexico. The peninsula extends 1300 km south-southeast from the US boundary to Cape San Lucas in the south. The peninsula is bounded on the east by a complex structural depression whose floor lies below sea level and deepens toward the southeast. The structural depression is the result of the displacement of the San Andreas Fault. The peninsula is divided from north to south into three morpho-tectonic sub-provinces called the Peninsular Ranges, the central region, and Southern Cape region. The poorly exposed eastern half of the Peninsular Ranges consists of the oldest rocks on the Peninsula Range consisting of weakly metamorphosed sandstone, shale, limestone, and basic volcanic rock. Fossils date the sediments from Precambrian to Triassic. The next sequence consists of younger rocks on the western Peninsula Range consisting of several thousand meters of metasedimentary and meta-volcanic rocks of Middle Cretaceous age intruded by numerous plutons. Plutons consist of tonalites, quartz diorites, granodiorites, gabbros, diorites, and adamellites. Plutons make up about 40 percent of the Baja California surface area. Post batholithic marine sedimentary sequence consisting of Late Cretaceous to Early Tertiary age forms a narrow belt along the west coast.

The Peró coastal plain is one of the three morphological compartments located between Búzios and Arraial do Cabo, on the east coast of Rio de Janeiro State, characterized by the occurrence of dune fields, driven by northeasterly winds, obliquely oriented in relation to the coastline. In order to evaluate the stability of the coastline as well as of the dune system a topographical and sedimentological characterrization of the different morphodynamic units was made, consisting of topographic and bathymetric profiling, evaluation of eolian sediment transport through sediment traps, sediment sampling for grain size analysis and comparison of aerial photographs. The results indicate that during the period of investigation sediment transport from the beach-foredune to the main dune field was largely inhibited by the presence of vegetation, and that sediment transport was limited to the reworking of its own sediment stock. Climatic oscillation toward drier periods, whether the result of gl...

The aeration characteristics of plunging breakers in the deep sea are described using a similarity with plunging jets. A large two-dimensional jet facility provides new experimental data on the number and sizes of the entrained bubbles and the resulting airwater interface area. The results enable new calculations of the air-water gas transfer contribution of the plunging breakers. The results are consistent with experimental field observations and emphasise the role of plunging breakers in the aeration process of the oceans.

Spatial planning in coastal regions has emerged as a major issue in the 21 st century due to the potential impacts of the changing climate and the associated rising sea levels in coastal regions. This paper explores the potential impacts of climate change and the vulnerability of the coast of Vietnam based upon geodetic information and the present coastal development. It then discusses how sustainable spatial planning approaches could be used to reduce vulnerability to climate change and ensure sustainable coastal adaptation of Vietnam's coastal zone. Based on a large-scale flood risk assessment, the study identified that non-structural approach could be used by Vietnam to adapt her low-lying coastline in the North and the South to climate change as this strategy enables vulnerable areas to be occupied for longer before eventual retreat. However, structural adaption policies could be pursued at the central coast which has high elevation and relatively hard geology. The paper revealed that sustainable and successful adaptation to climate change could be achieved if it is perceived as a process similar to spatial planning. It should be planed, implemented well in advance, monitored and evaluated before the occurrence of a natural disaster or an environmental change. Based on this, it recommended that Vietnam should develop and implement coastal adaptation policies now in order to forestalled huge impacts of future climate related disasters. The paper concludes that though coastal adaptation to climate change is a new phenomenon, it does apply key principles of spatial planning concepts and therefore recommended that spatial planning principles should be adopted for the development and implementation of sustainable coastal adaption policies to reduce the impacts of climate change.

Capitolo 4. -Individuazione delle categorie di stakeholder locali interessati dalla gestione dei siti in un'ottica di perequazione territoriale e dei costi diretti ed indiretti associati all'applicazione delle misure previste dai Piani di Gestione .

The quality of seawater in enclosed water basins can be negatively affected by inadequate exchange of seawater. Various culverts (pipe culverts, box culverts, and duct culverts) are presented in the paper as an efficient solution for preventing stagnation of seawater. In addition to positive influence of culvert-induced higher circulation of seawater in the basin, the wave energy penetrating during stormy weather into the protected area via culverts may be a limiting factor. Basic culvert shaping recommendations, relying on the study of previous research and structural solutions for culverts used on Croatian coast, are also presented in the paper.

The wave propagation and flow modules of the TELEMAC system have been applied to the "Porto di Lido" entrance of the Venice Lagoon. Wave-current interactions were analysed by direct coupling of the phase-averaged model TOMAWAC and of the two-dimensional depth-averaged flow TELEMAC 2D model. ARTEMIS software was separately applied to estimate the effect of refraction. The model includes the "Porto di Lido" entrance, one of the three channels connecting the Lagoon and the Adriatic Sea. The aim of the analysis is to evaluate the wave climate and the harbour tranquillity of a planned landing cruise, recently proposed in order to prevent the cruise ships from entering the Lagoon and mooring near San Marco. Several tests were performed and the results permit a comparison between the present condition and a future scenario including the planned terminal (landing cruise).

The aim of this work was to know the diversity of thrips on flowers of major spontaneous plants present in lemon orchards in Famaillá (Tucumán, Argentina). Twenty samples were collected every 15-20 days, between September 2014 and February 2015, except in July-August 2015 as the plants under study were absent. Samples consisted of the extraction of 30 flowers of Trifolium repens L. (Fabaceae), Commelina communis L. (Commelinaceae), Bidens pilosa L., Taraxacum officinale L. (Asteraceae), Solanum nigrum L. (Solanaceae), located below the canopy of 10 lemon trees randomly selected in the study plot. The thrips obtained were identified on the basis of microscopic slides, which are deposited in the collection of INBIAL-UNJu and the Entomology laboratory at EEA-INTA Famaillá. Fifteen species of the following families were recorded: Aeolothripidae (Franklinothrips tenuicornis), Thripidae (Dinurothrips vezenyii Bagnall, Neohydatothrips sidae JC Crawford, Arorathrips mexicanus (DL Crawford),...

This paper explores the problem of allocation of potential places of refuge for a ship in distress along the Estonian coast of the Gulf of Finland balancing the advantage for the affected ship and for the environment resulting from bringing the ship into a place of refuge. The integrated oil accident response simulation environment (PISCES II, ArcGis spatial modeling tools and Bayesian Belief Networks) proved to be instrumental for operational decision support in the case of a hypothetical oil accident. The knowledge of the ecological sensitivity of the Estonian coastal sea in the Gulf of Finland is used to estimate the probability of expected ecological damage associated with different towing directions of the vessel in distress. It is shown that the choice of the most favorable towing direction of the vessel in distress depends on the season, the position of the accident, and the ecological sensitivity level of the coastal sea area concerned.

This paper investigates the applicability of Bayesian inference to oil spill related situation assessment in order to facilitate the Net Environmental Benefit Analysis (NEBA) based decisions in evaluating the threat or probable overall environmental impact of the spill. Bayesian networks are believed to be useful in integrating the NEBA related information imported from 1) oil spill scene surveillance, 2) simulation results on an oil spill incident with human response, and 3) ecological sensitivity maps. This paper exemplifies the use of Bayesian Belief Networks in answering the questions: can the oil spill be combated at sea, and if it cannot then is the oil threatening a sensitive environment?

RESUME : Les rivages sableux ont retenu l’attention de façon particulière au cours des dernières décennies, notamment depuis les années 1980. L’attention était concentrée, d’abord, sur la question de leur érosion et leur protection. Aujourd’hui, plusieurs sont figés par différents ouvrages créés dans le cadre d’une défense lourde ou par des espaces plus ou moins étendus gagnés sur la mer par remblayage.
Ayant perdu le soutien que leur procurait leur avant-dune et/ou coupées de leur arrière-pays immédiat, certaines plages ont connu une concentration accrue de l’action des vagues et fini par perdre ce qui leur restait de leur substance sableuse naturelle. Une nouvelle conjoncture s’y est installée ; les vagues travaillent dans le matériel des ouvrages de protection et des remblayages précités. Les premières conséquences annoncent, tant que ces plages n’ont pas fait l’objet d’un travail de rechargement conséquent, un changement important dans la nature et la granulométrie de leur matériel devenu de plus en plus grossier, hétérogène et beaucoup moins attractif que le sable d’antan. Dans le front des remblayages, les coupes exhumées par les vagues révèlent parfois un matériel comportant souvent des substances nocives et pouvant être à l’origine de différentes formes de dégradation ainsi que des risques pour les baigneurs.
Si bien qu’après la concentration sur les problèmes de l’érosion ou parallèlement à elle, on aura à gérer, dans certains rivages anthropisés, de nouveaux problèmes.
Mots-clés : Tunisie, Maroc, plages, érosion, risques, environnement

NEW RISKS AND FORMS OF DEGRADATION IN THE BEACHES OF ANTHROPIZED COASTS (CASES IN TUNISIA AND MOROCCO)
ABSTRACT: Sandy shores have received particular attention in recent decades, particularly since the 1980s. Effort was often focused, first, on their erosion and their protection. Today, several are frozen by different structures created as part of a heavy defense or by more or less extensive spaces gained by backfilling works.
Having lost the support provided by their foredunes and/or cut off from their immediate hinterland, many beaches experienced an increased concentration of wave action and ended up losing what remained of their natural sandy substance. A new situation sets in; the waves work in the material of the aforementioned protective structures and backfilling works. The first consequences indicate, as long as the shores have not undergone significant sandy nourishment, a significant change in the nature and grain size. The material stirred by the waves is increasingly coarse, heterogeneous and much less attractive than the originel sand. In the front of the embankments, the waves reveal material often containing harmful substances which can cause different forms of degradation as well as risks for swimmers.
So that after focusing on the problems of erosion, or in parallel with it, we will have to manage new problems.
Keywords: Tunisia, Morocco, beaches, erosion, risks, environment

1.1 Introduction 19 1.2 Scale concept 22 1.2.1 Time scales and spatial scales in coastal behaviour 22 1.2.2 Process scales in coastal behaviour 23 1.3 Dealing with decadal behaviour of the Holland coast 26 1.3.1 Introduction 26 1.3.2 Approaches to the study of large-scale coastal behaviour 27 1.3.3 Studying decadal developments of the Holland coast from field data 29 1.4 Objectives and outline of the thesis 32 The study area: the Holland coast 2.1 2.2 2.3 2.4

Une base de données numériques d'états de mer en Méditerranée est en cours de construction à partir de simulations effectuées avec le logiciel de TOMAWAC sur la période 1979-2008 afin de venir compléter l'actuelle base de donnée ANEMOC couvrant la façade Atlantique-Manche-Mer du Nord des côtes françaises. Les champs de vent utilisés en entrée sont issus de la réanalyse météorologique NCEP2 du U.S. Climate Diagnostics Center of the National Oceanic and Atmospheric Administration (CDC-NOAA). Les résultats du modèle sont comparés à des mesures de bouées et des mesures satellitaires altimétriques. Les premières comparaisons des résultats de simulations aux mesures montrent un biais moyen négatif (sous-estimation) de la hauteur significative d'état de mer, qu'il convient d'améliorer en travaillant sur les champs de vent et en ajustant les paramètres physiques des termes puits / sources du modèle d'états de mer.

The present contribution constitutes the first comprehensive attempt to (a) record the spatial characteristics of the beaches of the Aegean archipelago (Greece), a critical resource for both the local and national economy, and (b) provide a rapid assessment of the impacts of the long-term and episodic sea level rise (SLR) under different scenarios. Spatial information and other attributes (e.g., presence of coastal protection works and backshore development) of the beaches of the 58 largest islands of the archipelago were obtained on the basis of remote-sensed images available on the web. Ranges of SLR-induced beach retreats under different morphological, sedimentological and hydrodynamic forcing, and SLR scenarios were estimated using suitable ensembles of cross-shore (1-D) morphodynamic models. These ranges, combined with empirically derived estimations of wave run-up induced flooding, were then compared with the recorded maximum beach widths to provide ranges of retreat/erosion and flooding at the archipelago scale. The spatial information shows that the Aegean “pocket” beaches may be particularly vulnerable to mean sea level rise (MSLR) and episodic SLRs due to (i) their narrow widths (about 59 % of the beaches have maximum widths < 20 m), (ii) their limited terrestrial sediment supply, (iii) the substantial coastal development and (iv) the limited existing coastal protection. Modeling results indeed project severe impacts under mean and episodic SLRs, which by 2100 could be devastating. For example, under MSLR of 0.5 m – representative concentration pathway (RCP) 4.5 of the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate change (IPCC) – a storm-induced sea level rise of 0.6 m is projected to result in a complete erosion of between 31 and 88 % of all beaches (29–87 % of beaches are currently fronting coastal infrastructure and assets), at least temporarily. Our results suggest a very considerable risk which will require significant effort, financial resources and policies/regulation in order to protect/maintain the critical economic resource of the Aegean archipelago.

Island beaches, which form significant natural and economic resources, are under increasing erosion risk due to sea level rise. The present contribution proposes an integrated methodological framework for the evaluation of the socioeconomic significance of beaches and their vulnerability to sea level rise and the design of effective adaptation measures. The approach comprises four steps: (i) beach ranking on the basis of their socioeconomic significance and vulnerability in order to prioritize adaptation responses; (ii) monitoring of the hydro-and morphodynamic regime of the most highly ranking beaches using field observations and modelling, (iii) assessment of the sediment volumes required for beach nourishment under different scenarios of sea level rise and nourishment designs; (iv) evaluation of the marine aggregate potential of the adjacent areas that can be used for beach nourishment. The framework was applied to the Greek island of Chios, which has many beaches that are already under erosion. The methodology was shown to provide a structured approach for the assessment and response to erosion of the most vulnerable beach.

Changes in beach morphology are frequent, varying from small to larger spatio-temporal scales, being subjected to the ever-changing hydrodynamic action. Swash zone motions have direct impact on beach morphology and are necessary parameters for appropriate coastal management and hazard mitigation. This study investigates spatiotemporal variability in swash motion and shoreline dynamics, which additionally are essential from regulatory boundaries for appropriate spatial planning of the beach zone. The traditional mapping techniques commonly lack the temporal resolution needed for accurate mapping of the swash zone dynamics. An autonomous coastal optical system was deployed at a dissipative, microtidal sandy beach (Marmari, Kos Island) and provided high-frequency hourly records of the shoreline and the wave run-up/run-down positions, simultaneously to a wave logger deployed offshore the beach. Results reveal significant variability in shoreline and wave run-up maximum, even under moderate incoming wave action. The system's automatization process is robust, capable in providing accurate morphological data, which are crucial for coastal planning.

In these contribution dynamic processes in a beach complex are introduced. Diferent wave transformation zones as waves arrive to the coast are described. Processes of sediment accumulation landwards in a beach context are also explained. In these sense, the two current sytems wave driven (longshore currents and rip currents) are described. Finally the different beach subenvironments are characterized by dynamic processes.

This contribution presents the results of a study on the shoreline variability of a natural perched urban beach (Ammoudara, N. Crete, Greece). Shoreline variability was monitored in high spatio-temporal resolution using time series of coastal video images and a novel, fully automated 2-D shoreline detection algorithm. Ten-month video monitoring showed that cross-shore shoreline change was, in some areas, up to 8 m with adjacent sections of the shoreline showing contrasting patterns of beach loss or gain. Variability increased in spring/early summer and stabilized until the end of the summer when partial beach recovery commenced. Correlation of the patterns of beach change with wave forcing (as recorded at an offshore wave buoy) is not straightforward; the only discernible association was that particularly energetic waves from the northern sector can trigger changes in the patterns of shoreline variability and that increased variability might be sustained by increases in offshore wave steepness. It was also found that the fronting beachrock reef exerts significant geological control on beach hydrodynamics. Hydrodynamic modelling and observations during an energetic event showed that the reef can filter wave energy in a highly differential manner, depending on its local architecture. In some areas, the reef allows only low-energy waves to impinge on the shoreline, whereas elsewhere penetration of higher waves is facilitated by the low elevation and limited width of the reef or by the presence of an inlet. Wave/reef interaction can also generate complex circulation patterns, including rip currents that appeared to be also constrained by the reef architecture.

A bifacial, bipointed, flaked stone knife was found during the expansion of a house cellar in the early 20 th Century in Sanford, Maine. It was brought to my attention in 2011 by the current owner of the artifact. The geological surface map indicated that the find spot was likely an exposure of late Pleistocene deposits and the form of the artifact resembles some other bipointed knives that may be of Late Glacial Maximum origin. The locality was investigated through test excavations 1 with the geology verified, however, no in-place archaeological deposits were encountered. Dating of the deposits by optical stimulated luminescence (OSL) was also unsuccessful. Never the less there is circumstantial evidence that the knife may have been in late Pleistocene deposits and that it could represent an early use of the area when it was an interface between glacial outwash and the ocean beach. A small stone end scraper, typical of Late Pleistocene/early Holocene cultures, has also been recovered from the locality, but other than its type, there is no indication of its time of origin.

Global climate change will accelerate sea level rise that will continue to affect Bangladesh coast through increased salinity intrusion of low-lying areas. The situation becomes more critical when a severe cyclone makes landfall in the coastal region resulting sudden propagation of huge amount of landward saline water intrusion through estuaries. In this study, a SIDR like cyclone (i.e. intensity same as SIDR but hydrodynamic condition different) is selected to simulate changes of salinity intrusion. A calibrated and validated salinity model (Delft3D) and storm surge model (Delft Dashboard) was used to simulate the surface water salinity values. Salinity isohaline lines, comparing normal dry condition and climatecyclone driven scenarios were drawn to generate an overview on the level of resulting landward salinity intrusion. Upstream and downstream (including the sea level rise) boundaries are generated by using results from hydrology and ocean models. Estuarine salinity will increa...

Branding can be simply defined as differentiation something from the same kind of products and services in marketing. In spatial terms, cities are the places where urban population lives. During the globalization wave, some cities became more attractive in countries for foreigners. The historical values, educational opportunities, flamboyant architecture and natural beauties of those cities are unique and attract foreign investment and make them international destinations. The main idea behind this develop ment is successful branding of those cities. Globalization transformed to a new era where local entities and values became well known objects in all over the world. This new concept called glocalization where small, simple assets save their historical and physical values and meantime attract many visitors besides its inhabitants from all around the world. The application of international relations concept to city images and planning brought the idea of city branding to academic literature. Brand improvement of cities enables local governors and businessman to have sustainable economic development and financial resources for new investments. The multiplier effect of those investments improves local development capacity of those provinces. Coastal parts of M uğla city are recognized as an international travel destination around the world. It has more than half of the yacht marina capacity of Turkey. The demand for marinas in M uğla also increased in last decade. The special aura of this sector is related with the high segment customer profiles. The region has natural beauty, rich cultural and historical background and warm environment. These are the focal point for city branding in international arena. In this chapter the evaluation of City branding of M uğla with special interest on M arinas will be explored. I will define and conceptualize brand cities and their potentials in international literature. After listing the marinas around M uğla region their capacities and superiorities will be compared to its rivals in M editerranean basin. Finally how this service helps the branding process of M uğla will be analyzed.

Coastal wetlands are dynamic ecosystems that exist at the interface between land and sea. They represent environments with a great diversity of habitats and communities, high carbon sequestration capacity and a wide range of ecosystem services. In the Mediterranean, the largest coastal wetlands are found in deltaic areas like that of the Ebro River (Spain), which has a coastline length of approximately 50 km, occupying a total area of 325 km2. The Ebro Delta is included in different national and international frameworks for environmental conservation, despite which there are several risks that threaten it. The lack of sedimentary contributions due to the regulation of the Ebro riverbed (irrigation, reservoirs, and hydroelectric power generation) has caused erosion and the retreat of certain sections of its coastline. To this situation of sediment deficit must be added the threat posed by the effects of global change, such as the rise in sea level, the increase in temperature and in ...

The Peró coastal plain is one of the three morphological compartments located between Búzios and Arraial do Cabo, on the east coast of Rio de Janeiro State, characterized by the occurrence of dune fields, driven by northeasterly winds, obliquely oriented in relation to the coastline. In order to evaluate the stability of the coastline as well as of the dune system a topographical and sedimentological characterrization of the different morphodynamic units was made, consisting of topographic and bathymetric profiling, evaluation of eolian sediment transport through sediment traps, sediment sampling for grain size analysis and comparison of aerial photographs. The results indicate that during the period of investigation sediment transport from the beach-foredune to the main dune field was largely inhibited by the presence of vegetation, and that sediment transport was limited to the reworking of its own sediment stock. Climatic oscillation toward drier periods, whether the result of gl...

A trunk sewer interceptor plus a treatment plant and a disposal system are the main components of most large wastewater management infrastructures. Wastewater processing starts in the sewer is continued in the treatment plant and generally ends after disposal of final products (sludge and treated effluent). Long-sea outfalls can be the most efficient disposal systems in many coastal areas because they (i) promote dilution of the effluent into receiving waters during plume rising, (ii) transport wastewater off the coastline and (iii) can discharge the water in areas with low residence time. In this paper Costa do Estoril Waste Water Management System is described. The impact of the discharge on the water column and sediments is very light and only detectable in the vicinity of the diffuser. Modeling has shown that the low impact in the water column is a consequence of the hydrodynamic and biogeochemical characteristics of the receiving waters. The small impact in sediments (e.g. the absence of the "piling effect") is a consequence of the wave climate, which resuspends fine material, making it available to be transported by tidal and wind currents. Monitoring results and model predictions have been used to demonstrate that a secondary treatment would mean no environmental benefit for the receiving waters, an essential condition to obtain a license for operating with a primary treatment out of the bathing period. This is the optimal exploitation configuration that complies with the European Directive on urban wastewater treatment. This paper presents a synthesis of the studies supporting the demand for operating with a primary treatment out of the bathing period.