Flooding of Sandy Beaches in a Changing Climate. The Case of the Balearic Islands (NW Mediterranean)

The fate of the beaches around the world has paramount importance as they are one of the main assets for touristic activities and act as a natural barrier for coastal protection in front of marine storms. Climate change could put them at risk as sea levels rise and changes in the wave characteristics may dramatically modify their shape. In this work, a new methodology has been developed to determine the flooding of sandy beaches due to changes in sea level and waves. The methodology allows a cost-effective and yet accurate estimation of the wave runup for a wide range of beach equilibrium profiles and for different seagrass coverage. This, combined with regional projections of sea level and wave evolution, has allowed a quantification of the future total water level and coastline retreat for 869 beaches across the Balearic Islands for the next decades as a function of greenhouse gases emission scenario. The most pessimistic scenario (RCP8.5) at the end of the century yields an averaged percentage of flooded area of 66% under mean conditions which increases up to 86% under extreme conditions. Moreover, 72 of the 869 beaches of the region would permanently disappear while 314 would be completely flooded during storm episodes. Under a moderate scenario of emissions (RCP4.5), 37 beaches would permanently disappear while 254 would disappear only during storm episodes. In both cases, the average permanent loss of beach surface at the end of the century would be larger than 50%, rising over 80% during storm conditions. The results obtained for the Balearic Islands can be extrapolated to the rest of the Mediterranean as the beaches in all the regions have similar characteristics and will be affected by similar changes in sea level and wave climate. These projections indicate that adaptation plans for beach areas should be put in place as soon as possible.

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Vertical and lateral distribution of Foraminifera and Ostracoda in the East Frisian Wadden Sea – developing a transfer function for relative sea-level change

Geologica Belgica ◽

10.20341/gb.2019.007 ◽

2019 ◽

Vol 22 (3-4) ◽

pp. 99-110

Author(s):

JULIANE SCHEDER ◽

PETER FRENZEL ◽

FRIEDERIKE BUNGENSTOCK ◽

MAX ENGEL ◽

HELMUT BRÜCKNER ◽

...

Keyword(s):

Transfer Function ◽

Sea Level ◽

Environmental Parameters ◽

Coastal Protection ◽

Relative Sea Level ◽

New Approach ◽

Sea Levels ◽

Wide Range ◽

Vertical Error ◽

Rising Sea Levels

In light of rising sea levels and increased storm surge hazards, detailed information on relative sea-level (RSL) histories and local controlling mechanisms is required to support future projections and to better prepare for future coastal-protection challenges. This study contributes to deciphering Holocene RSL changes at the German North Sea coast in high resolution by developing a transfer function for RSL change. Recent associations of Foraminifera and Ostracoda from low intertidal to supratidal settings of the barrier island of Spiekeroog in combination with environmental parameters (granulometry, C/N, TOC, salinity) were investigated and quantified in elevation steps of 15 cm in order to generate a first transfer function (TF) of Holocene RSL change. In a future step, the TF can be applied to the stratigraphic record. Our data show a clear vertical zonation of foraminifer and ostracod taxa between the middle salt marsh and the tidal flat with very few individuals in the sand flat area, suggesting removal by the tidal current or poor preservation. Multivariate statistics identify the elevation, i.e. the inundation frequency, as main driving factor. The smallest vertical error (49 cm) is associated with an entirely new approach of combining Foraminifera and Ostracoda for a TF. Advantages of the TF over classical RSL indicators such as basal and intercalated peat – beside the relatively narrow indicative meaning – include the possible application to a wide range of intertidal facies and that it does not depend on compaction-prone peat.

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Changes in beach shoreline due to sea level rise and waves under climate change scenarios: application to the Balearic Islands (Western Mediterranean)

10.5194/nhess-2016-361 ◽

2016 ◽

Cited By ~ 1

Author(s):

Alejandra R. Enríquez ◽

Marta Marcos ◽

Amaya Álvarez-Ellacuría ◽

Alejandro Orfila ◽

Damià Gomis

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Climate Models ◽

Regional Climate ◽

Wave Climate ◽

Sandy Beaches ◽

Western Mediterranean ◽

Climate Change Scenarios ◽

Swash Zone ◽

Climate Scenarios

Abstract. In this work we assess the impacts in reshaping coastlines as a result of sea level rise and changes in wave climate. The methodology proposed combines the SWAN and SWASH wave models to resolve the wave processes from deep waters up to the swash zone in two micro-tidal sandy beaches in Mallorca Island, Western Mediterranean. In a first step, the modelling approach is validated with observations from wave gauges and from the shoreline inferred from video monitoring stations, showing a good agreement between them. Afterwards, the modelling setup is applied to the 21st century sea level and wave projections under two different climate scenarios, RCP45 and RCP85. Sea level projections were retrieved from state of the art regional estimates, while wave projections were obtained from regional climate models. Changes in the coastline are explored under mean and extreme wave conditions. Our results indicate that the studied beaches would suffer a coastal retreat between 7 and up to 50 m, equivalent to half of the present-day aerial beach surface, under the climate scenarios considered.

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Evaluating future beach reduction in a changing climate: Methodologies and uncertainties.

10.5194/egusphere-egu2020-10094 ◽

2020 ◽

Author(s):

Miguel Agulles ◽

Gabriel Jordà

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Climate Change Impacts ◽

Cost Effective ◽

Swash Zone ◽

Wave Runup ◽

First Results ◽

High Degree ◽

The Impact ◽

The Waves

In recent years there have been endless coastal actions that have substantially modified the equilibrium conditions of much of the coastline. This fact, along with an unprecedented coastal population growth and the projected sea level rise, make beaches a particularly vulnerable region to climate change impacts. In particular, there is a clear need to quantify the reduction of the beach area due to the combination effects of the sea level rise and changes in the waves in the swash zone, under different future climate scenarios.In this work different methodologies are developed to estimate the retreat of the coastline and to quantify the associated uncertainties. The methodologies have been applied to three beaches of the Balearic Islands, which have been continuously monitored during the last decade. The different methodologies imply the use of models to propagate the waves from deep waters to shallow depths and to compute wave runup. The results are compared to simpler approaches based on empirical formulations that provide a cost-effective solution to cover large domains. All the different approaches are validated with coastal wave recorders (AWACs) and data from cameras from which wave runup is estimated. Furthermore, a sensitivity analysis has been performed to assess the impact of uncertainties in the beach bathymetry.The first results show that under the RCP8.5 scenario, the expected coastline retreat under mean conditions would be of ~22 &#177; 5 meters at mid-century. Considering extreme waves conditions, the retreat would reach ~40 &#177; 5 meters.It is worth mentioning that the three studied beaches have a very different exposure, granulometry and maritime climate, and in spite of that, the estimated uncertainty level is relatively low (~10-25%) in all of them. Therefore, the proposed methodologies along with their uncertainty analysis, might be extrapolated to any sandy beach with a reasonable high degree of accuracy.&#160;

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Changes in beach shoreline due to sea level rise and waves under climate change scenarios: application to the Balearic Islands (western Mediterranean)

Natural Hazards and Earth System Science ◽

10.5194/nhess-17-1075-2017 ◽

2017 ◽

Vol 17 (7) ◽

pp. 1075-1089 ◽

Cited By ~ 23

Author(s):

Alejandra R. Enríquez ◽

Marta Marcos ◽

Amaya Álvarez-Ellacuría ◽

Alejandro Orfila ◽

Damià Gomis

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Climate Models ◽

Regional Climate ◽

Wave Climate ◽

Sandy Beaches ◽

Western Mediterranean ◽

Climate Change Scenarios ◽

Swash Zone ◽

Climate Scenarios

Abstract. This work assesses the impacts in reshaping coastlines as a result of sea level rise and changes in wave climate. The methodology proposed combines the SWAN and SWASH wave models to resolve the wave processes from deep waters up to the swash zone in two micro-tidal sandy beaches in Mallorca island, western Mediterranean. In a first step, the modelling approach has been validated with observations from wave gauges and from the shoreline inferred from video monitoring stations, showing a good agreement between them. Afterwards, the modelling set-up has been applied to the 21st century sea level and wave projections under two different climate scenarios, representative concentration pathways RCP45 and RCP85. Sea level projections have been retrieved from state-of-the-art regional estimates, while wave projections were obtained from regional climate models. Changes in the shoreline position have been explored under mean and extreme wave conditions. Our results indicate that the studied beaches would suffer a coastal retreat between 7 and up to 50 m, equivalent to half of the present-day aerial beach surface, under the climate scenarios considered.

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Extreme sea levels at different global warming levels

Nature Climate Change ◽

10.1038/s41558-021-01127-1 ◽

2021 ◽

Vol 11 (9) ◽

pp. 746-751

Author(s):

Claudia Tebaldi ◽

Roshanka Ranasinghe ◽

Michalis Vousdoukas ◽

D. J. Rasmussen ◽

Ben Vega-Westhoff ◽

...

Keyword(s):

Global Warming ◽

Sea Level ◽

Global Climate ◽

Climate Mitigation ◽

Frequency Change ◽

Sea Levels ◽

Wide Range ◽

Extreme Sea Levels ◽

Multimethod Approach ◽

The Tropics

AbstractThe Paris agreement focused global climate mitigation policy on limiting global warming to 1.5 or 2 °C above pre-industrial levels. Consequently, projections of hazards and risk are increasingly framed in terms of global warming levels rather than emission scenarios. Here, we use a multimethod approach to describe changes in extreme sea levels driven by changes in mean sea level associated with a wide range of global warming levels, from 1.5 to 5 °C, and for a large number of locations, providing uniform coverage over most of the world’s coastlines. We estimate that by 2100 ~50% of the 7,000+ locations considered will experience the present-day 100-yr extreme-sea-level event at least once a year, even under 1.5 °C of warming, and often well before the end of the century. The tropics appear more sensitive than the Northern high latitudes, where some locations do not see this frequency change even for the highest global warming levels.

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Coastal Flooding in the Balearic Islands During the Twenty-First Century Caused by Sea-Level Rise and Extreme Events

Frontiers in Marine Science ◽

10.3389/fmars.2021.676452 ◽

2021 ◽

Vol 8 ◽

Author(s):

Pau Luque ◽

Lluís Gómez-Pujol ◽

Marta Marcos ◽

Alejandro Orfila

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Storm Surges ◽

Coastal Flooding ◽

Sandy Beaches ◽

Balearic Islands ◽

First Century ◽

Shoreline Retreat ◽

Mean Sea Level ◽

Recreational Services

Sea-level rise induces a permanent loss of land with widespread ecological and economic impacts, most evident in urban and densely populated areas. Potential coastline retreat combined with waves and storm surges will result in more severe damages for coastal zones, especially over insular systems. In this paper, we quantify the effects of sea-level rise in terms of potential coastal flooding and potential beach erosion, along the coasts of the Balearic Islands (Western Mediterranean Sea), during the twenty-first century. We map projected flooded areas under two climate-change-driven mean sea-level rise scenarios (RCP4.5 and RCP8.5), together with the impact of an extreme event defined by the 100-year return level of joint storm surges and waves. We quantify shoreline retreat of sandy beaches forced by the sea-level rise (scenarios RCP4.5 and RCP8.5) and the continuous action of storm surges and waves (modeled by synthetic time series). We estimate touristic recreational services decrease of sandy beaches caused by the obtained shoreline retreat, in monetary terms. According to our calculations, permanent flooding by the end of our century will extend 7.8–27.7 km2 under the RCP4.5 scenario (mean sea-level rise between 32 and 80 cm by 2100), and up to 10.9–36.5 km2 under RCP8.5 (mean sea-level rise between 46 and 103 cm by 2100). Some beaches will lose more than 50% of their surface by the end of the century: 20–50% of them under RCP4.5 scenario and 25–60% under RCP8.5 one. Loss of touristic recreational services could represent a gross domestic product (GDP) loss up to 7.2% with respect to the 2019 GDP.

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THE ECONOMICS OF SEA LEVEL RISE: FORECASTING FLOOD DAMAGE COST

Coastal Engineering Proceedings ◽

10.9753/icce.v36.risk.79 ◽

2018 ◽

pp. 79

Author(s):

Angela Schedel ◽

John Schedel

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Cost Effective ◽

Flood Damage ◽

Economic Benefits ◽

Adaptation Measures ◽

Sea Levels ◽

Damage Costs ◽

Effective Option ◽

Potential Damage

Globally, sea levels are rising. As property owners decide whether and how to protect their assets to minimize future damage, a comprehensive understanding of potential damage costs is vital to making informed, cost-effective decisions. These estimates, when combined with probabilistic modeling of future flood events and sea level rise, can be used to forecast the future costs of flood inundation. Using this information, the economic benefits of different adaptation measures are compared to select the most cost-effective option. This study describes a methodology using Expected Monetary Value (EMV) to make risk-informed decisions for adapting vulnerable assets to sea level rise.

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GESLA Version 3: A major update to the global higher-frequency sea-level dataset

10.31223/x5mp65 ◽

2021 ◽

Author(s):

Ivan Haigh ◽

Marta Marcos ◽

Stefan Talke ◽

Philip Woodworth ◽

John Hunter ◽

...

Keyword(s):

Sea Level ◽

Storm Surges ◽

Coastal Engineering ◽

Multiple Sources ◽

Sea Levels ◽

The Third ◽

Wide Range ◽

The World ◽

Extreme Sea Levels ◽

Level Analysis

This paper describes a major update to the quasi-global, higher-frequency sea-level dataset known as GESLA (Global Extreme Sea Level Analysis). Versions 1 (released 2009) and 2 (released 2016) of the dataset have been used in many published studies, across a wide range of oceanographic and coastal engineering-related investigations concerned with evaluating tides, storm surges, extreme sea levels and other related processes. The third version of the dataset (released 2021), presented here, contains twice the number of years of data (91,021), and nearly four times the number of records (5,119), compared to version 2. The dataset consists of records obtained from multiple sources around the world. This paper describes the assembly of the dataset, its processing and its format, and outlines potential future improvements. The dataset is available from https://www.gesla.org.

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MALAYSIAN SEA WATER LEVEL PATTERN DERIVED FROM 19 YEARS TIDAL DATA

Jurnal Teknologi ◽

10.11113/jt.v79.9908 ◽

2017 ◽

Vol 79 (5) ◽

Author(s):

Ami Hassan Md Din ◽

Amalina Izzati Abdul Hamid ◽

Nornajihah Mohammad Yazid ◽

Astina Tugi ◽

Nur Fadila Khalid ◽

...

Keyword(s):

Water Level ◽

Sea Level ◽

Sea Water ◽

Tide Gauge ◽

Sea Levels ◽

Wide Range ◽

Relative Water ◽

Level Information ◽

Tidal Data ◽

Sea Level Trend

Long-term water level changes have generally been estimated using tidal data. Tide gauges are common tools used to determine the continuous time series of relative water level. This paper presents an effort to interpret the water level from tidal data over Malaysian seas. There are 21 tide gauge stations involved and taken from Permanent Service for Mean Sea Level (PSMSL) with monthly averaged data from 1993 to 2011. The monthly tidal data is then converted to tidal sea level anomaly. For sea level trend analysis, robust fit regression is employed. Next, the sea levels were analysed based on the pattern of seasonal variation and extreme meteorological effects such as El-Nino and La-Nina. In summary, the relative sea level trend in Malaysian seas is rising and varying from 2 to 6.5 mm/yr. This study offers valuable sea level information to be applied in wide range of climatology, related environmental issue such as flood and global warming in Malaysia.

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Identifying Priority Areas for Coastal Protection Around Java, Indonesia

Jurnal Segara ◽

10.15578/segara.v17i1.9997 ◽

2021 ◽

Vol 17 (1) ◽

pp. 43

Author(s):

Jimy Kalther ◽

Akemi Itaya

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Cost Effective ◽

Northern Region ◽

Annual Rainfall ◽

Coastal Protection ◽

Protection Strategy ◽

Priority Areas ◽

Public Data ◽

Systematic Planning

Climate change-induced sea level rise will likely increase the severity of ongoing coastal disasters in Indonesia. The selection and concentration approach should be applied to minimize the costs of conservation when budgets are limited. Prioritizing is then effective in terms of cost effectiveness. We aimed to identify priority areas for coastal protection against sea level rise around Java, Indonesia, using the Marxan model. The model uses systematic planning to select prioritized areas for coastal protection. Three scenarios were developed based on ecological, economic, and disaster elements that were exacerbated by sea level rise. A scenario is defined as a particular simulation circumstance based on assumptions about extrinsic drivers, parameters, and the structure of the model. Coastline length, mangrove coverage, low-elevation area, fishpond area, human settlement area, and the area of zones with the potential for annual rainfall increases acquired from DIVA-GIS and WorldClim were set as environmental factors. There were 60 areas facing the coast among 117 areas. For those protection, it would be fairly costly. We were able to narrow that number down from 18.8% to 62.4% from 117 areas using our method. This might become very cost effective. The most prioritized areas were located in the northern region of Java. These areas can be a focus of preferential effort and funding for conservation. The results of this study will help to make the protection strategy based on not only the magnitude of damage but also the total perspective using public data that is relatively easy to obtain.

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