Uncertainties of creek evolution in coastal wetlands facing sea-level rise

Author(s):  
Xiaorong Li ◽  
Nicoletta Leonardi ◽  
Andy Plater

<p>Adaptation of coastal areas facing climate change is a global challenge. Some of these low‐lying regions are commonly managed and engineered to reduce damage, loss of life, and environmental degradation caused by natural hazards originating from the sea. However, sea-level rise and changes in storm regimes are putting unprecedented pressure on these managed systems, forcing the adoption of “no active intervention” or “managed realignment” strategies in areas where “hold the line” options cannot be justified due to financial constraints. The aim of this research is to explore how disintegration of sea defences would affect creek topology under present day and future sea level rise scenarios, using the Hesketh marsh as a case study.  A reduced complexity numerical model is applied to produce ensemble predictions for analysis. Without the presence of vegetation, results suggest that creek geometry efficiency and density of tidal creeks are insensitive to sea level rise.</p><p>The model assumes the erodibility of the wetland is homogeneous and constant which leaves room for improvement because coastal environment is subject to changes as a result of global climate change and human activities. Changes in environmental stressors, such as sea level rise, elevated CO<sub>2</sub> concentration, changing storm patterns, etc. could adjust the resistance of the wetland to erosion in either way. Hence, the adequacy of current parameterizations of soil erodibility in numerical models requires further investigation.</p>

2021 ◽  
Vol 13 (13) ◽  
pp. 7503
Author(s):  
Alexander Boest-Petersen ◽  
Piotr Michalak ◽  
Jamal Jokar Arsanjani

Anthropogenically-induced climate change is expected to be the contributing cause of sea level rise and severe storm events in the immediate future. While Danish authorities have downscaled the future oscillation of sea level rise across Danish coast lines in order to empower the coastal municipalities, there is a need to project the local cascading effects on different sectors. Using geospatial analysis and climate change projection data, we developed a proposed workflow to analyze the impacts of sea level rise in the coastal municipalities of Guldborgsund, located in Southeastern Denmark as a case study. With current estimates of sea level rise and storm surge events, the island of Falster can expect to have up to 19% of its landmass inundated, with approximately 39% of the population experiencing sea level rise directly. Developing an analytical workflow can allow stakeholders to understand the extent of expected sea level rise and consider alternative methods of prevention at the national and local levels. The proposed approach along with the choice of data and open source tools can empower other communities at risk of sea level rise to plan their adaptation.


2017 ◽  
Vol 17 (9) ◽  
pp. 1559-1571 ◽  
Author(s):  
Yann Krien ◽  
Bernard Dudon ◽  
Jean Roger ◽  
Gael Arnaud ◽  
Narcisse Zahibo

Abstract. In the Lesser Antilles, coastal inundations from hurricane-induced storm surges pose a great threat to lives, properties and ecosystems. Assessing current and future storm surge hazards with sufficient spatial resolution is of primary interest to help coastal planners and decision makers develop mitigation and adaptation measures. Here, we use wave–current numerical models and statistical methods to investigate worst case scenarios and 100-year surge levels for the case study of Martinique under present climate or considering a potential sea level rise. Results confirm that the wave setup plays a major role in the Lesser Antilles, where the narrow island shelf impedes the piling-up of large amounts of wind-driven water on the shoreline during extreme events. The radiation stress gradients thus contribute significantly to the total surge – up to 100 % in some cases. The nonlinear interactions of sea level rise (SLR) with bathymetry and topography are generally found to be relatively small in Martinique but can reach several tens of centimeters in low-lying areas where the inundation extent is strongly enhanced compared to present conditions. These findings further emphasize the importance of waves for developing operational storm surge warning systems in the Lesser Antilles and encourage caution when using static methods to assess the impact of sea level rise on storm surge hazard.


2017 ◽  
Author(s):  
Yann Krien ◽  
Bernard Dudon ◽  
Jean Roger ◽  
Gaël Arnaud ◽  
Narcisse Zahibo

Abstract. In the Lesser Antilles, coastal inundations from hurricane-induced storm surges cause great threats to lives, properties, and ecosystems. Assessing current and future storm surge hazard with sufficient spatial resolution is of primary interest to help coastal planners and decision makers develop mitigation and adaptation measures. Here, we use wave-current numerical models and statistical methods to investigate worst case scenarios and 100-year surge levels for the case study of Martinique, under present climate or considering a potential sea-level rise. Results confirm that the wave setup plays a major role in Lesser Antilles, where the narrow island shelf impedes the piling-up of large amounts of wind-driven water on the shoreline during extreme events. The radiation stress gradients thus contribute significantly to the total surge, up to 100 % in some cases. The non-linear interactions of sea level rise with bathymetry and topography are generally found to be relatively small in Martinique, but can reach several tens of centimeters in low-lying areas where the inundation extent is strongly enhanced compared to present conditions. These findings further emphasize the importance of waves for developing operational storm surge warning systems in the Lesser Antilles, and encourage caution when using static methods to assess the impact of sea level rise on storm surge hazard.


2008 ◽  
Vol 242 ◽  
pp. 367-379 ◽  
Author(s):  
M. VanKoningsveld ◽  
J. P. M. Mulder ◽  
M. J. F. Stive ◽  
L. VanDerValk ◽  
A. W. VanDerWeck

2010 ◽  
Vol 1 (5) ◽  
pp. 729-740 ◽  
Author(s):  
Jaap C. J. Kwadijk ◽  
Marjolijn Haasnoot ◽  
Jan P. M. Mulder ◽  
Marco M. C. Hoogvliet ◽  
Ad B. M. Jeuken ◽  
...  

2017 ◽  
Author(s):  
Aiqing Feng ◽  
Jiangbo Gao ◽  
Shaohong Wu ◽  
Yanzhong Li ◽  
Xiliu Yue

Abstract. Extreme water levels, caused by the joint occurrence of storm surges and high tides, always lead to super floods along coastlines. Given the ongoing climate change, this study explored the risk of future sea-level rise on the extreme inundation by combining P-III model and losses assessment model. Taking Rongcheng as a case study, the integrated risk of extreme water levels was assessed for 2050 and 2100 under three Representative Concentration Pathways (RCP) scenarios of 2.6, 4.5, and 8.5. Results indicated that the increase in total direct losses would reach an average of 60 % in 2100 as a 0.82 m sea-level rise under RCP 8.5. In addition, affected population would be increased by 4.95 % to 13.87 % and GDP (Gross Domestic Product) would be increased by 3.66 % to 10.95 % in 2050 while the augment of affected population and GDP in 2100 would be as twice as in 2050. Residential land and farmland would be under greater flooding risk in terms of the higher exposure and losses than other land-use types. Moreover, this study indicated that sea-level rise shortened the recurrence period of extreme water levels significantly and extreme events would become common. Consequently, the increase in frequency and possible losses of extreme flood events suggested that sea-level rise was very likely to exacerbate the extreme risk of coastal zone in future.


2021 ◽  
Author(s):  
Clara E Estrela Segrelles ◽  
Miguel Ángel Pérez Martín ◽  
Gabriel Gómez Martínez

<p>Sea level rise produced by climate change severely affects coastal ecosystems. The increase in the area below sea level facilitates the penetration of the marine wedge and causes an increase in soil salinity. Coastal wetlands are areas of great ecological importance due to the richness of flora and fauna that inhabit them. A change in salinity conditions could lead to a reduction or loss of habitat for the wetland biota. Based on RCP4.5 and RCP8.5 CMIP5 multimodel scenarios, in the Western Mediterranean coast, the sea level will rise 0.16 m in the short term (2026 - 2045) and 0.79 m in 2100. Also, high-end scenarios indicate that sea level will rise between 1.35 m and 1.92 m in the long term.</p><p>A sea level rise analysis has been developed in the coastal wetlands of Júcar River Basin District (JRBD). The results show that coastal wetlands are the mainly area affected in the JRBD, so the 90% of the area under the sea level are wetlands. L’Albufera de Valencia is the main wetland in this basin and, also the main wetland affected. It is an anthropized humid zone, regulated by users through gates to preserve the adequate water level for agricultural and environmental purposes such as rice cultivation around the lake and bird habitats conservation, especially in winter. The outcome of the study shows a significative increase in the area below the sea from 507 ha and 4.2 hm<sup>3</sup> of water volume at present to 3,244 ha that represents 42.6 hm<sup>3</sup> of water volume in the short term. In the long term, the area below the sea is 7,253 ha which means 118.4 hm<sup>3</sup> of water volume in the percentile 50 scenario and, in the worst extreme scenario, it is 13,896 ha that represents 289.7 hm<sup>3</sup> of water volume. This leads to a redefinition of the lake management levels as a climate change adaptation measure to prevent the lake salinization and severe impacts in the lake ecosystem. L’Albufera lake levels need to be increased in the next years to avoid the sea water penetration, related to the sea level rise. Thus, in the short term the lake levels must be increased around 0.16 m and, in the long term, L’Albufera levels must be increased around 0.8 m.</p>


2012 ◽  
Vol 278 ◽  
pp. 8-19 ◽  
Author(s):  
Abiy S. Kebede ◽  
Robert J. Nicholls ◽  
Susan Hanson ◽  
Mustafa Mokrech

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