scholarly journals Coral Reef Geometry and Hydrodynamics in Beach Erosion Control in North Quintana Roo, Mexico

2021 ◽  
Vol 8 ◽  
Author(s):  
Mireille Escudero ◽  
Borja G. Reguero ◽  
Edgar Mendoza ◽  
Fernando Secaira ◽  
Rodolfo Silva
Keyword(s):  
Coral Reefs ◽  
Shoreline Change ◽  
Breaking Waves ◽  
Sandy Beaches ◽  
Beach Erosion ◽  
Hydrodynamic Performance ◽  
Coastal Protection ◽  
Reef Restoration ◽  
Shoreline Protection ◽  
Erosion Mitigation

Coral reefs are increasingly recognized for their shoreline protection services. The hydrodynamic performance of this ecosystem is comparable to artificial low-crested structures often used in coastal protection, whose objective is to emulate the former. Coral reefs also provide other important environmental services (e.g., food production, habitat provision, maintenance of biodiversity and social and cultural services) and leave almost no ecological footprint when conservation and restoration actions are conducted to maintain their coastal protection service. However, studies have focused on their flood protection service, but few have evaluated the morphological effects of coral reefs through their ability to avoid or mitigate coastal erosion. In this paper, we investigate the relation between shoreline change, reefs’ geometry and hydrodynamic parameters to elucidate the physics related to how the Mesoamerican Reef in Mexico protects sandy coastlines from erosion. Using numerical wave propagation and historical shoreline change calculated from satellite imagery, a direct correlation was found between shoreline movement, the depths and widths of reef flats, changes in the wave energy flux, and the radiation stresses of breaking waves. The findings indicate that the most remarkable efficacy in preventing beach erosion is due to reefs with shallow crests, wide reef flats, a dissipative lagoon seabed, located at ∼300 m from the coastline. The results provide essential insights for reef restoration projects focused on erosion mitigation and designing artificial reefs in microtidal sandy beaches. Results are limited to wave-dominated coasts.

scholarly journals Numerical Modeling of Failure Mechanisms in Articulated Concrete Block Mattress as a Sustainable Coastal Protection Structure

2021 ◽  
Vol 13 (22) ◽  
pp. 12794
Author(s):  
Ramin Safari Ghaleh ◽  
Omid Aminoroayaie Yamini ◽  
S. Hooman Mousavi ◽  
Mohammad Reza Kavianpour
Keyword(s):  
Numerical Modeling ◽  
Concrete Block ◽  
Breaking Waves ◽  
Physical Models ◽  
Coastal Protection ◽  
Similarity Parameter ◽  
Environmental Friendliness ◽  
Shoreline Protection ◽  
Concrete Blocks ◽  
Run Up

Shoreline protection remains a global priority. Typically, coastal areas are protected by armoring them with hard, non-native, and non-sustainable materials such as limestone. To increase the execution speed and environmental friendliness and reduce the weight of individual concrete blocks and reinforcements, concrete blocks can be designed and implemented as Articulated Concrete Block Mattress (ACB Mat). These structures act as an integral part and can be used as a revetment on the breakwater body or shoreline protection. Physical models are one of the key tools for estimating and investigating the phenomena in coastal structures. However, it does have limitations and obstacles; consequently, in this study, numerical modeling of waves on these structures has been utilized to simulate wave propagation on the breakwater, via Flow-3D software with VOF. Among the factors affecting the instability of ACB Mat are breaking waves as well as the shaking of the revetment and the displacement of the armor due to the uplift force resulting from the failure. The most important purpose of the present study is to investigate the ability of numerical Flow-3D model to simulate hydrodynamic parameters in coastal revetment. The run-up values of the waves on the concrete block armoring will multiply with increasing break parameter (0.5<ξm−1,0<3.3) due to the existence of plunging waves until it (Ru2%Hm0=1.6) reaches maximum. Hence, by increasing the breaker parameter and changing breaking waves (ξm−1,0>3.3) type to collapsing waves/surging waves, the trend of relative wave run-up changes on concrete block revetment increases gradually. By increasing the breaker index (surf similarity parameter) in the case of plunging waves (0.5<ξm−1,0<3.3), the low values on the relative wave run-down are greatly reduced. Additionally, in the transition region, the change of breaking waves from plunging waves to collapsing/surging (3.3<ξm−1,0<5.0), the relative run-down process occurs with less intensity.

scholarly journals COUNTERMEASURE AGAINST EROSION BEHIND SUBMERGED BREAKWATER DUE TO SEA LEVEL RISE

2018 ◽  
pp. 62
Author(s):  
Yoshiaki Kuriyama ◽  
Masayuki Banno
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Land Subsidence ◽  
West Coast ◽  
Shoreline Change ◽  
Sandy Beaches ◽  
Beach Erosion ◽  
Relative Sea Level ◽  
Submerged Breakwater ◽  
Relative Sea Level Rise

Submerged breakwaters are considered to be preferable countermeasures against beach erosion where the availability of sediments for nourishment is limited and tourism is prevalent because submerged breakwaters do not interfere with the view of the horizon from the shore. However, sandy beaches protected by submerged breakwaters are assumed to be vulnerable to relative sea level rise (SLR) and land subsidence because the crests of submerged breakwaters are below sea level. Kuriyama and Banno (2016) numerically predicted the future shoreline change under SLR and land subsidence on the Niigata West coast in Japan, which is protected by submerged breakwaters. The prediction showed that the shoreline will retreat 60 m over the next 100 years. In this study, we investigated the effects of countermeasures against the erosion due to SLR and land subsidence.

Serviços ecossistêmicos prestados por recifes de coral nas ilhas de Tinharé e Boipeba, Baixo Sul da Bahia, Brasil

2018 ◽  
Author(s):  
Carla Isobel Elliff
Keyword(s):  
Ecosystem Services ◽  
Coral Reefs ◽  
Current Model ◽  
Management Strategies ◽  
Environmental Indicators ◽  
Management Actions ◽  
Shoreline Protection ◽  
Fringing Reefs ◽  
Integrated Valuation ◽  
Reef Decline

Coral reefs provide important ecosystem services to coastal communities. The Archipelago of Tinhar?e andBoipeba, Bahia, Brazil, are mostly surrounded by fringing reefs, which have undergone several chronichuman impacts. The objective of the present study was to apply an ecosystem-based approach byanalyzing the ecosystem services provided by the coral reefs of the Archipelago of Tinhar?e and Boipeba inorder to support management actions and serve as a tool for coastal management. Ecosystem serviceswere assessed through the observation of environmental indicators of their occurrence and by using asuite of models from the Integrated Valuation of Environmental Services and Tradeoffs (InVEST) softwarecombined with data from the Atlantic and Gulf Rapid Reef Assessment (AGRRA) protocol database. Theservices of greatest occurrence were food provision, habitat maintenance, shoreline protection andrecreation. While the main stressful factors were tourism activities, the absence of a sewage system andfisheries. The coral reefs presented potential for shoreline protection along 50.5% of the islands. Moreover,46.8% of the shoreline would present moderate to high vulnerability in case of coral reef disappearance.The coincidence of areas with high risk of loss in the capacity to provide services and highvulnerability in the scenario of absence of reefs is concerning. Thus, the current model for tourism usedin the area should be altered, as should new management strategies be implemented, which can bringbenefits and avoid reef decline.

scholarly journals Development of a conceptual framework for the management of biodiversity and ecosystem services in the Mexican Caribbean

2020 ◽  
Vol 20 (suppl 1) ◽  
Author(s):  
Andrés Sánchez-Quinto ◽  
Julliet Correa da Costa ◽  
Nadia S. Zamboni ◽  
Fábio H. C. Sanches ◽  
Silas C. Principe ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Coral Reefs ◽  
Conceptual Framework ◽  
Conceptual Model ◽  
Coastal Region ◽  
Ecosystem Model ◽  
Coastal Protection ◽  
Coastal Environments ◽  
Management Actions ◽  
Global Biodiversity

Abstract: Coral reefs and mangroves support rich biodiversity and provide ecosystem services that range from food, recreational benefits and coastal protection services, among others. They are one of the most threatened ecosystems by urbanization processes. In this context, we developed a conceptual framework for the management of biodiversity and ecosystem services for these coastal environments. We based our workflow on two sections: “Information base” and “Governance” and use the Puerto Morelos Coastal region as a case study for coastal protection. Puerto Morelos is between two of the most touristic destinations of Mexico (Playa del Carmen and Cancun) that has experienced an increase of population in the past four decades resulting in an intensification of multiple threats to its ecosystems. We characterized the two ecosystems with a “Management Units” strategy. An expert-based ecosystem services matrix was also described in order to connect mangroves and coral reef ecosystems with the multiple beneficiaries. Then an ecosystem model (conceptual model and Global Biodiversity model) was developed. The conceptual model was useful in understanding the interplay processes between systems regarding the ecosystem service of “Coastal Protection”. The Global Biodiversity model evidenced the human-induced shifts in the biodiversity for mangrove and coral reefs ecosystems. Also, a projection for 2035 of “best” and “worst” scenarios was applied using GLOBIO3. A DPSIR conceptual framework was used to analyze environmental problems regarding ecosystem services maintenance. Finally, we evaluated a set of policies associated with these ecosystems that favor coastal protection integrity. This framework facilitates the identification of the most relevant processes and controls about the provision of coastal protection service. It can also be useful to better target management actions and as a tool to identify future management needs to tackle the challenges preventing more effective conservation of coastal environments.

scholarly journals Assessment of shoreline positional uncertainty using remote sensing and GIS techniques: A case study from the east coast of India

2021 ◽  
Vol 71 (3) ◽  
pp. 249-263
Author(s):  
Kongeswaran Thangaraj ◽  
Sivakumar Karthikeyan
Keyword(s):  
Linear Regression ◽  
Coastal Zone ◽  
East Coast ◽  
Coastal Zone Management ◽  
Storm Surges ◽  
Shoreline Change ◽  
Coastal Protection ◽  
East Coast Of India ◽  
Zone Management ◽  
2004 Tsunami

The focus of this research was to assess the shoreline changes by comparing the satellite data from 1980 to 2020. The study area falls in the region between Kodiakarai and Nagapattinam of the east coast of India, which has frequently been distressed by storm surges and cyclones in the Bay of Bengal. The Digital Shoreline Analysis System (DSAS) detects and measures the erosional and accretional shoreline positions through the statistics of the Shoreline Change Envelope, Net Shoreline Movement, End Point Rate, Linear Regression Rate, and Weighted Linear Regression. The results show that the shoreline from Kodiakkarai to Nagapattinam suffered severe erosion of 17.7% in total with an average annual erosion rate of 3.4 m/year from 1980 to 2020 and the rate of erosion ranged between 0.1 m/year to 19.8 m/year. About 90.5% of the total shoreline was faced high erosion during the period between 2000 and 2010. The maximum erosion was about 1061 m from 2000 to 2010, the maximum accretion was found to be 1002 m in transects at Kodiakkarai during 2010 to 2020. After the effect of 2004 tsunami, the corresponding changes in littoral currents caused the drastic erosion and accretion in this shoreline. The DSAS prediction model shows that 19.3% of the current shoreline will erode in 2030. The maximum predicted erosion is 406 m at Kodiakkarai and the maximum predicted accretion is 148 m at Nagapattinam region. The coastal zone from Kodiakkarai to Nagapattinam needs special attention to prevent the erosion and it is recommended to build suitable coastal protection structures along the coast for sustainable development and to execute the coastal zone management for this region.

scholarly journals Deep uncertainties in shoreline change projections: an extra-probabilistic approach applied to sandy beaches

2021 ◽  
Author(s):  
Rémi Thiéblemont ◽  
Gonéri Le Cozannet ◽  
Jérémy Rohmer ◽  
Alexandra Toimil ◽  
Moisés Álvarez-Cuesta ◽  
...  
Keyword(s):  
Sea Level ◽  
Probabilistic Approach ◽  
Shoreline Change ◽  
Sandy Beaches ◽  
Climate Mitigation ◽  
Deep Uncertainty ◽  
Mean Sea Level ◽  
Uncertain Variables ◽  
Knowledge Based ◽  
Global Mean Sea Level

Abstract. Global mean sea-level rise and its acceleration are projected to aggravate coastal erosion over the 21st century, which constitutes a major challenge for coastal adaptation. Projections of shoreline retreat are highly uncertain, however, namely due to deeply uncertain mean sea-level projections and the absence of consensus on a coastal impact model. An improved understanding and a better quantification of these sources of deep uncertainty are hence required to improve coastal risk management and inform adaptation decisions. In this work we present and apply a new extra-probabilistic framework to develop shoreline change projections of sandy coasts that allows considering intrinsic (or aleatory) and knowledge-based (or epistemic) uncertainties exhaustively and transparently. This framework builds upon an empirical shoreline change model to which we ascribe possibility functions to represent deeply uncertain variables. The model is applied to two local sites in Aquitaine (France) and Castellón (Spain). First, we validate the framework against historical shoreline observations and then develop shoreline change projections that account for possible (although unlikely) low-end and high-end mean sea-level scenarios. Our high-end projections show for instance that shoreline retreats of up to 200 m in Aquitaine and 130 m in Castellón are plausible by 2100, while low-end projections revealed that 58 m and 37 m modest shoreline retreats, respectively, are also plausible. Such extended intervals of possible future shoreline changes reflect an ambiguity in the probabilistic description of shoreline change projections, which could be substantially reduced by better constraining SLR projections and improving coastal impact models. We found for instance that if mean sea-level by 2100 does not exceed 1 m, the ambiguity can be reduced by more than 50 %. This could be achieved through an ambitious climate mitigation policy and improved knowledge on ice-sheets.

BEACH PROCESSES AND SHORE PROTECTION ALONG THE NORTHERN COLOMBIA COAST

2020 ◽  
Vol 1 (2) ◽  
pp. 60-85
Author(s):  
PING WANG
Keyword(s):  
Beach Erosion ◽  
Trade Wind ◽  
Sand Transport ◽  
Shore Protection ◽  
Tropical Zone ◽  
Longshore Sediment Transport ◽  
Longshore Transport ◽  
Shoreline Protection ◽  
Beach Processes ◽  
Northeast Trade Wind

The shoreline of northern Colombia is located in the tropical zone along the south coast of Caribbean Sea. Its coastal processes are strongly influenced by the northeast trade wind, which results in the dominating northeasterly approaching wave occurring over 95% of the time. This drives a persistent southwestward longshore sand transport. The state of the beach along the generally northeast-southwest trending northern Colombia coast is strongly influenced by this constant unidirectional longshore sediment transport. At locations where this westward longshore sand transport is interrupted, naturally or  anthropogenically, beach accretion occurs along the updrift shoreline coupled with erosion at the downdrift side. Natural interruption of longshore transport can be caused by tidal inlets, protruding headland, shoreline orientation change, and nearshore bathymetry variations. Anthropogenic interruption of the longshore transport along the northern Colombia coast is mainly caused by the construction of groins, as well as harbors at some locations. Numerous groins were constructed due to their local success in creating beach accretion at the drift side. However, severe beach erosion occurs along the downdrift shoreline. Shoreline protection along the northern Colombia coast, and coasts in the tropical area in general, should carefully consider the persistent unidirectional longshore sand transport and should not be misguided by the local updrift accumulation as being a successful project.

Estimate of Storm Induced Beach Erosion Through the ETS Approach

2008 ◽  
Author(s):  
Rosaria E. Musumeci ◽  
Carla Faraci ◽  
Felice Arena ◽  
Enrico Foti
Keyword(s):  
Return Period ◽  
Extreme Events ◽  
Coastal Erosion ◽  
Beach Erosion ◽  
Coastal Protection ◽  
Shoreline Retreat ◽  
Submerged Breakwater ◽  
The One

In the present paper the risk of beach erosion is evaluated by applying the Equivalent Triangular Storm (ETS). The selected case study is ‘La Plaja’ beach located in the South of Catania, Sicily. The proposed approach has shown that when the ETS model is applied, a shoreline retreat has been found which on average overestimates the one obtained by means of actual storm data of about 35%. The model has been applied for the determination of the return period of shoreline recession due to beach erosion during extreme events in order to recover risk maps, which can provide useful information in the planning of coastal interventions. Finally the model has been applied to predict the shoreline retreat in the presence of a submerged breakwater, confirming that the introduction of such coastal protection work strongly limits the risk of coastal erosion.

Erosion Mitigation Using Submerged Breakwater Composed of Artificial Reefs

2015 ◽  
Vol 744-746 ◽  
pp. 1171-1174
Author(s):  
Kyu Han Kim ◽  
Bum Shick Shin
Keyword(s):  
Wave Attenuation ◽  
Three Dimensional ◽  
Artificial Reef ◽  
Beach Erosion ◽  
Artificial Reefs ◽  
Return Flow ◽  
Two Dimensional ◽  
Submerged Breakwater ◽  
Erosion Mitigation ◽  
Study Offer

In this study, erosion mitigation by submerged breakwater with artificial reefs is investigated among other means of countermeasures. Beach erosion mechanism near the submerged breakwater and the performance of artificial reef blocks are analyzed in the laboratory. Two-dimensional and three-dimensional laboratory experiments are applied to the analysis. The results of two-dimensional experiments prove that new artifi-cial blocks showed a better performance than the existing blocks in terms of wave attenuation due to wave breaking turbulence near the crest of the structure. Three-dimensional experiments show reduced return flow velocity by half by installing another type of new artificial block in between submerged breakwaters. Return flow has been creating vulnerability in countermeasures by submerged breakwater. Therefore, artifi-cial reef blocks suggested by this study offer solutions to the existing mitigation problems with submerged breakwater.

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