Sea level rise in the Venetian lagoon inferred from the 150-year-long tidal record

2020 ◽  
Author(s):  
Sara Rubinetti ◽  
Carla Taricco ◽  
Davide Zanchettin ◽  
Enrico Arnone ◽  
Angelo Rubino
Keyword(s):  
Time Series ◽  
Sea Level Rise ◽  
Sea Level ◽  
City Centre ◽  
Reference Level ◽  
Decadal Scale ◽  
Historical Series ◽  
Venetian Lagoon ◽  
The City

<p>The city of Venice (Northern Italy), together with its lagoon, is a historic, cultural and artistic heritage of inestimable value. One of its peculiarities consists in the recurrent storm surge phenomena, referred to as <em>acqua alta</em>. Sea level rise and local subsidence made their frequency to increase dramatically with respect to the past, causing severe damages to the lagoon and in particular to the city centre, as during the exceptional high tide verified on November 12, 2019.<br>Here we show the analysis of the historical time series of tidal maxima and minima recorded in the Venetian lagoon, covering the period 1872-2018. It is the longest and most complete historical series of the Venetian area and one of the longest records of the entire Mediterranean region. During this period, the relative sea level height has increased of about 30 cm with respect to the reference level, while the average number of <em>acqua alta</em> events – evaluated over a 40-year time interval - has passed from about 4 to 70 per year. These events usually occur during the fall season (from October to December), even if a not negligible number has been also recorded during winter. Therefore, we analyse the October-March average annual time series with advanced spectral analysis methods, like Monte Carlo Singular Spectrum Analysis (MC-SSA), to extract and reconstruct the significant variability modes characterizing the record. They are the increasing long-term trend and components with multidecadal, decadal and interannual periods. The trend results from the superposition on the global eustacy of the local subsidence affecting the Venetian lagoon, which is due to both natural causes and human activities. We also discuss the possible linkage of the other significant spectral components to large scale climatic patterns. In particular, the decadal-scale oscillation is one of the most important variability modes affecting Northern Italian hydrology.<br>Finally, we apply simple statistical methods (autoregressive models and feed-forward neural networks) to forecast the long-term evolution of sea level over the next ten years. In this contribution, we illustrate results from this state of the art two-fold statistical prediction system that provides robust predictions of sea level in the Venetian lagoon for the next decade and discuss them in the light of current longer-term projections of future sea level rise. Finally, we will test the predictive skill of the applied methods using tidal measurements recorded during 2019, to verify if our predictions are able to describe tidal variability characterizing the current year.       </p>

scholarly journals SEA-LEVEL EFFECT ON ANNUAL CYCLIC BEACH MORPHOLOGY IN SWASH ZONE AT HASAKI COAST

2018 ◽  
pp. 35
Author(s):  
Masayuki Banno ◽  
Yoshiaki Kuriyama
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Observation Data ◽  
Swash Zone ◽  
Beach Profile ◽  
Beach Morphology ◽  
Bruun Rule ◽  
Decadal Scale ◽  
And Sea Level

depend on the accurate knowledge of the beach response to sea level regime on multi-time scale. For the long-term beach response, Bruun (1962) suggested that the equilibrium beach profile would move to new equilibrium profile in response to a rising sea level. In this concept called as Bruun rule, the upper part of the beach profile is eroded due to the sea level rise, resulting in the shoreline retreat. It is widely used for the future shoreline prediction. However, the Bruun rule predicts just only the final beach state with a constant wave impinging for an infinite period after sea level rise. On the other hand, simultaneous function of wave and sea level is more important on interannual to decadal-scale beach response. El niño in 2015 and 2016 increased wave energy and sea level, corresponding to large beach erosion across the US west coast (Barnard et al., 2017). Sea level influences the response sensitivity to the wave forcing as a subordinate factor on the morphological change. High water level anomalies made the beach more eroded even if the wave condition was equal. Beach morphology in the swash zone often changes on a 1-year cycle due to seasonal wave conditions. The effect of sea level on the annual cyclic beach morphology in swash zone is still unclear because long-term beach observation data required for the analysis are difficult to obtain. In this study, we investigated the simultaneous effects of the wave and sea level on annual cyclic beach morphology in the swash zone with spectrum analysis for 25-year Hasaki beach observation data.

scholarly journals A Holistic Framework for Evaluating Adaptation Approaches to Coastal Hazards and Sea Level Rise: A Case Study from Imperial Beach, California

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1324
Author(s):  
David Revell ◽  
Phil King ◽  
Jeff Giliam ◽  
Juliano Calil ◽  
Sarah Jenkins ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Public Trust ◽  
Adaptation Strategy ◽  
Public Benefits ◽  
Study Results ◽  
Local Risk ◽  
Over Time

Sea level rise increases community risks from erosion, wave flooding, and tides. Current management typically protects existing development and infrastructure with coastal armoring. These practices ignore long-term impacts to public trust coastal recreation and natural ecosystems. This adaptation framework models physical responses to the public beach and private upland for each adaptation strategy over time, linking physical changes in widths to damages, economic costs, and benefits from beach recreation and nature using low-lying Imperial Beach, California, as a case study. Available coastal hazard models identified community vulnerabilities, and local risk communication engagement prioritized five adaptation approaches—armoring, nourishment, living shorelines, groins, and managed retreat. This framework innovates using replacement cost as a proxy for ecosystem services normally not valued and examines a managed retreat policy approach using a public buyout and rent-back option. Specific methods and economic values used in the analysis need more research and innovation, but the framework provides a scalable methodology to guide coastal adaptation planning everywhere. Case study results suggest that coastal armoring provides the least public benefits over time. Living shoreline approaches show greater public benefits, while managed retreat, implemented sooner, provides the best long-term adaptation strategy to protect community identity and public trust resources.

Long-term legacy of delayed climate mitigation in global glacier response

2021 ◽  
Author(s):  
Fabien Maussion ◽  
Quentin Lejeune ◽  
Ben Marzeion ◽  
Matthias Mengel ◽  
David Rounce ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Greenhouse Gas ◽  
Sea Level ◽  
Climate Mitigation ◽  
Delayed Response ◽  
Glacier Change ◽  
Mountain Glaciers ◽  
Glacier Runoff ◽  
The Impact

<p>Mountain glaciers have a delayed response to climate change and are expected to continue to melt long after greenhouse gas emissions have stopped, with consequences both for sea-level rise and water resources. In this contribution, we use the Open Global Glacier Model (OGGM) to compute global glacier volume and runoff changes until the year 2300 under a suite of stylized greenhouse gas emission characterized by (i) the year at which anthropogenic emissions culminate, (ii) their reduction rates after peak emissions and (iii) whether they lead to a long-term global temperature stabilization or decline. We show that even under scenarios that achieve the Paris Agreement goal of holding global-mean temperature below 2 °C, glacier contribution to sea-level rise will continue well beyond 2100. Because of this delayed response, the year of peak emissions (i.e. the timing of mitigation action) has a stronger influence on mit-term global glacier change than other emission scenario characteristics, while long-term change is dependent on all factors. We also discuss the impact of early climate mitigation on regional glacier change and the consequences for glacier runoff, both short-term (where some basins are expected to experience an increase of glacier runoff) and long-term (where all regions are expecting a net-zero or even negative glacier contribution to total runoff), underlining the importance of mountain glaciers for regional water availability at all timescales.</p>

scholarly journals Characterizing and minimizing the effects of noise in tide gauge time series: relative and geocentric sea level rise around Australia

2013 ◽  
Vol 194 (2) ◽  
pp. 719-736 ◽  
Author(s):  
Reed J. Burgette ◽  
Christopher S. Watson ◽  
John A. Church ◽  
Neil J. White ◽  
Paul Tregoning ◽  
...  
Keyword(s):  
Time Series ◽  
Sea Level Rise ◽  
Sea Level ◽  
Tide Gauge

scholarly journals Implementing Pre-Emptive Managed Retreat: Constraints and Novel Insights

2021 ◽  
Author(s):  
Judith Lawrence ◽  
Jonathan Boston ◽  
R Bell ◽  
S Olufson ◽  
R Kool ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
First Century ◽  
Current State ◽  
Adaptation Response ◽  
Extreme Flooding ◽  
Protective Structures ◽  
Implementation Gaps ◽  
Post Disaster

Purpose of Review: Managed retreat will be inevitable where other adaptation options, such as protective structures or building restrictions, provide only temporary respite or are otherwise uneconomic, technically impractical or both. Here, we focus on the implementation of pre-emptive managed retreat, providing examples of how it can be sequenced, socialised and given the governance enablers necessary for implementation. Recent Findings: Ongoing sea-level rise during the twenty-first century and beyond poses huge adaptation challenges, especially for low-lying coastal and floodplain settlements. Settlements are already functionally disrupted from repetitive non-extreme flooding and research shows that sea-level rise will impact far more people, far sooner than previously thought, as more powerful storms, heavy rainfall and rising groundwater coincide with higher tides. To date, most examples of managed retreat have been post-disaster responses following damage and disruption. Pre-emptive managed retreat, by contrast, has yet to become a well-accepted and widely practised adaptation response. Nevertheless, there are increasing examples of research and practice on how pre-emptive managed retreat can be designed, sequenced and implemented alongside other forms of adaptation within anticipatory forms of governance. Summary: The current state of knowledge about managed retreat is reviewed and critical insights and lessons for governance and policy-making are given. Several novel examples from New Zealand are presented to address some of the implementation gaps. Goals and principles are enunciated to inform long-term adaptation strategies.

scholarly journals Decadal-scale onset and termination of Antarctic ice-mass loss during the last deglaciation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Michael E. Weber ◽  
Nicholas R. Golledge ◽  
Chris J. Fogwill ◽  
Chris S. M. Turney ◽  
Zoë A. Thomas
Keyword(s):  
Mass Loss ◽  
Sea Level Rise ◽  
Sea Level ◽  
Ross Sea ◽  
Ice Sheet ◽  
Rate Of Change ◽  
Last Deglaciation ◽  
Decadal Scale ◽  
Ice Sheet Modeling ◽  
Global Sea Level

AbstractEmerging ice-sheet modeling suggests once initiated, retreat of the Antarctic Ice Sheet (AIS) can continue for centuries. Unfortunately, the short observational record cannot resolve the tipping points, rate of change, and timescale of responses. Iceberg-rafted debris data from Iceberg Alley identify eight retreat phases after the Last Glacial Maximum that each destabilized the AIS within a decade, contributing to global sea-level rise for centuries to a millennium, which subsequently re-stabilized equally rapidly. This dynamic response of the AIS is supported by (i) a West Antarctic blue ice record of ice-elevation drawdown >600 m during three such retreat events related to globally recognized deglacial meltwater pulses, (ii) step-wise retreat up to 400 km across the Ross Sea shelf, (iii) independent ice sheet modeling, and (iv) tipping point analysis. Our findings are consistent with a growing body of evidence suggesting the recent acceleration of AIS mass loss may mark the beginning of a prolonged period of ice sheet retreat and substantial global sea level rise.

scholarly journals Recent sea level rise on Ireland's east coast based on multiple tide gauge analysis

2020 ◽  
Author(s):  
Amin Shoari Nejad ◽  
Andrew C. Parnell ◽  
Alice Greene ◽  
Brian P. Kelleher ◽  
Gerard McCarthy
Keyword(s):  
Time Series ◽  
Sea Level Rise ◽  
Sea Level ◽  
Continuous Time ◽  
East Coast ◽  
Tide Gauge ◽  
Tide Gauges ◽  
Missing Value ◽  
Global Average ◽  
Good Agreement

Abstract. We analysed multiple tide gauges from the east coast of Ireland over the period 1938–2018. We validated the different time series against each other and performed a missing value imputation exercise, which enabled us to produce a homogenised record. The recordings of all tide gauges were found to be in good agreement between 2003–2015, though this was markedly less so from 2016 to the present. We estimate the sea level rise in Dublin port for this period at 10 mm yr−1. The rate over the longer period of 1938–2015 was 1.67 mm yr−1 which is in good agreement with the global average. We found that the rate of sea level rise in the longer term record is cyclic with some extreme upward and downward trends. However, starting around 1980, Dublin has seen significantly higher rates that have been always positive since 1996, and this is mirrored in the surrounding gauges. Furthermore, our analysis indicates an increase in sea level variability since 1980. Both decadal rates and continuous time rates are calculated and provided with uncertainties in this paper.

scholarly journals Delaying future sea-level rise by storing water in Antarctica

2016 ◽  
Vol 7 (1) ◽  
pp. 203-210 ◽  
Author(s):  
K. Frieler ◽  
M. Mengel ◽  
A. Levermann
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Energy Supply ◽  
Primary Energy ◽  
Ocean Water ◽  
Additional Mass ◽  
Dynamic Perspective ◽  
Primary Energy Supply ◽  
The Antarctic

Abstract. Even if greenhouse gas emissions were stopped today, sea level would continue to rise for centuries, with the long-term sea-level commitment of a 2 °C warmer world significantly exceeding 2 m. In view of the potential implications for coastal populations and ecosystems worldwide, we investigate, from an ice-dynamic perspective, the possibility of delaying sea-level rise by pumping ocean water onto the surface of the Antarctic ice sheet. We find that due to wave propagation ice is discharged much faster back into the ocean than would be expected from a pure advection with surface velocities. The delay time depends strongly on the distance from the coastline at which the additional mass is placed and less strongly on the rate of sea-level rise that is mitigated. A millennium-scale storage of at least 80 % of the additional ice requires placing it at a distance of at least 700 km from the coastline. The pumping energy required to elevate the potential energy of ocean water to mitigate the currently observed 3 mm yr−1 will exceed 7 % of the current global primary energy supply. At the same time, the approach offers a comprehensive protection for entire coastlines particularly including regions that cannot be protected by dikes.

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