scholarly journals MORPHOLOGICAL RESPONSE OF A REEF-FRONTED BEACH TO SEA LEVEL RISE AND REEF DEGRADATION

2020 ◽  
pp. 1
Author(s):  
Tom Baldock ◽  
William Ginzo
Keyword(s):  
Numerical Modelling ◽  
Sea Level Rise ◽  
Sea Level ◽  
Reef Flat ◽  
Physical Modelling ◽  
Sandy Beaches ◽  
Water Levels ◽  
Morphological Response ◽  
Fringing Reefs ◽  
Reef Degradation

The morphological response of reef-fronted beaches to sea level rise and reef degradation is investigated by physical modelling. Coral barrier and fringing reefs limit the wave energy reaching sandy beaches, providing protection to many communities worldwide (Ferrario et al., 2014). Sea level rise and loss of reef flat elevation through coral mortality are expected to alter water levels over such reefs in the future. Assessing the morphological response to these processes in the field is very difficult due to the timescale involved, and lack of data for current conditions. Numerical modelling of beach profile response is also poor, even for open coast sandy beaches, and there is limited work modelling of reef fronted beaches, although hydrodynamics can be modelled reasonably well (Buckley et al., 2014). Here, new experiments on beach response to rising water levels and reducing reef flat elevation without tides are presented and compared to a conceptual model that links total sediment transport to the wave height landward of the reef (Baldock et al., 2015). A summary of recent numerical modelling of 2D planform changes for the same scenario will also be presented.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/0ya0UH1Vpsk

scholarly journals Economic damages from Hurricane Sandy attributable to sea level rise caused by anthropogenic climate change

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Benjamin H. Strauss ◽  
Philip M. Orton ◽  
Klaus Bittermann ◽  
Maya K. Buchanan ◽  
Daniel M. Gilford ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Sea Level ◽  
East Coast ◽  
The United States ◽  
Hurricane Sandy ◽  
Water Levels ◽  
Anthropogenic Climate Change ◽  
Economic Damage ◽  
Sea Levels

AbstractIn 2012, Hurricane Sandy hit the East Coast of the United States, creating widespread coastal flooding and over $60 billion in reported economic damage. The potential influence of climate change on the storm itself has been debated, but sea level rise driven by anthropogenic climate change more clearly contributed to damages. To quantify this effect, here we simulate water levels and damage both as they occurred and as they would have occurred across a range of lower sea levels corresponding to different estimates of attributable sea level rise. We find that approximately $8.1B ($4.7B–$14.0B, 5th–95th percentiles) of Sandy’s damages are attributable to climate-mediated anthropogenic sea level rise, as is extension of the flood area to affect 71 (40–131) thousand additional people. The same general approach demonstrated here may be applied to impact assessments for other past and future coastal storms.

scholarly journals Quantifying Uncertainty in Exposure to Coastal Hazards Associated with Both Climate Change and Adaptation Strategies: A U.S. Pacific Northwest Alternative Coastal Futures Analysis

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 545
Author(s):  
Alexis K. Mills ◽  
Peter Ruggiero ◽  
John P. Bolte ◽  
Katherine A. Serafin ◽  
Eva Lipiec
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Sea Level ◽  
Performance Metrics ◽  
Coastal Flooding ◽  
Water Levels ◽  
Coastal Hazards ◽  
Policy Decisions ◽  
Management Decisions ◽  
Quantifying Uncertainty

Coastal communities face heightened risk to coastal flooding and erosion hazards due to sea-level rise, changing storminess patterns, and evolving human development pressures. Incorporating uncertainty associated with both climate change and the range of possible adaptation measures is essential for projecting the evolving exposure to coastal flooding and erosion, as well as associated community vulnerability through time. A spatially explicit agent-based modeling platform, that provides a scenario-based framework for examining interactions between human and natural systems across a landscape, was used in Tillamook County, OR (USA) to explore strategies that may reduce exposure to coastal hazards within the context of climate change. Probabilistic simulations of extreme water levels were used to assess the impacts of variable projections of sea-level rise and storminess both as individual climate drivers and under a range of integrated climate change scenarios through the end of the century. Additionally, policy drivers, modeled both as individual management decisions and as policies integrated within adaptation scenarios, captured variability in possible human response to increased hazards risk. The relative contribution of variability and uncertainty from both climate change and policy decisions was quantified using three stakeholder relevant landscape performance metrics related to flooding, erosion, and recreational beach accessibility. In general, policy decisions introduced greater variability and uncertainty to the impacts of coastal hazards than climate change uncertainty. Quantifying uncertainty across a suite of coproduced performance metrics can help determine the relative impact of management decisions on the adaptive capacity of communities under future climate scenarios.

Modelling the climate change impact on the largest White Sea estuarine areas

2021 ◽  
Author(s):  
Evgeniya Panchenko ◽  
Andrei Alabyan ◽  
Inna Krylenko ◽  
Serafima Lebedeva
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Sea Level ◽  
River Runoff ◽  
White Sea ◽  
Water Levels ◽  
Hydrodynamic Modelling ◽  
The White Sea ◽  
Runoff Changes ◽  
Flow Velocities

<p>Possible sea level rise and changes in hydrological regime of rivers are the major threats to estuarine systems. The sensibility of hydrodynamic regime of the Northern Dvina delta and the Onega estuary under various scenarios of climate change has been investigated. Hydrodynamic models HEC-RAS (USA, US Army Corps of Engineers Hydrologic Engineering Center) and STREAM_2D (Russia, authors V.Belikov et.al.) were used for analysis of estuarine flow regime (variations of water levels, discharges and flow velocities throughout tidal cycles). Input runoff changes were simulated for different climate scenarios using ECOMAG model (Russia, author Yu.Motovilov) based on data of global climate models (GSM) of CMIP5 project for the White Sea region.</p><p>ECOMAG modelling has demonstrated that the maximum river discharges averaged for 30-year period 2036 – 2065 can reduce for about 20 – 27% for the Onega and 15 – 20% for the Northern Dvina river compared against the historical period 1971 – 2000.Averaged minimum river discharges can reduce for about 33 – 45% for the Onega and 30 – 40% for the Northern Dvina.</p><p>The White Sea level rise by 0.27 m in average (with inter-model variation from 0.20 to 0.38 m) can took place by the middle of the XXI century according to input data of GSM models. The 12 scenarios of estuarine hydrodynamic changes were simulated for the both rivers based on combining river runoff changes and sea level elevation.</p><p>In general, the expected flow changes are negative for the local industry and population. According to modelling results for ‘high runoff/spring tide’ scenarios the flooding area in the Northern Dvina delta will increase by 13-20% depending on the intensity of sea level rise. In the low water seasons the distance from the river mouth to the upper boundary of the reach, where reverse currents can be observed, will move upstream by 8 - 36 km depending of sea/river conditions due to decrease in minimum river runoff. It may adversely effect on shipping conditions at the city of Arkhangelsk and on brackish water intrusion up-to industrial and communal water intakes.</p><p>The reverse currents also will intensify in the Onega estuary (tidal flow velocities increase for 11 – 19%) that leads to the change of the sediment regime and can significantly deteriorate the navigation conditions at the seaport of the Onega town. The problem of the intensification of salt intrusion can arise there as well.</p><p>The research was supported by the Russian Foundation for Basic Research (Projects No. 18- 05-60021 in development of the scenarios; No. 19-35-90032 in providing hydrodynamic modelling of the Onega; Project No. 19-35-60032 in providing hydrodynamic modelling of the Northern Dvina).</p>

A 6000-year record of ecological and hydrological changes from Laguna de la Leche, north coastal Cuba

2007 ◽  
Vol 67 (1) ◽  
pp. 69-82 ◽  
Author(s):  
Matthew C. Peros ◽  
Eduard G. Reinhardt ◽  
Anthony M. Davis
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Plant Macrofossils ◽  
Water Levels ◽  
Loss On Ignition ◽  
Coastal Lake ◽  
Freshwater Gastropods ◽  
Level Increase ◽  
Pollen Rain ◽  
Calcareous Microfossils

AbstractLaguna de la Leche, north coastal Cuba, is a shallow (≤ 3 m), oligohaline (∼ 2.0–4.5‰) coastal lake surrounded by mangroves and cattail stands. A 227-cm core was studied using loss-on-ignition, pollen, calcareous microfossils, and plant macrofossils. From ∼6200 to ∼ 4800 cal yr BP, the area was an oligohaline lake. The period from ∼ 4800 to ∼ 4200 cal yr BP saw higher water levels and a freshened system; these changes are indicated by an increase in the regional pollen rain, as well as by the presence of charophyte oogonia and an increase in freshwater gastropods (Hydrobiidae). By ∼ 4000 cal yr BP, an open mesohaline lagoon had formed; an increase in salt-tolerant foraminifers suggests that water level increase was driven by relative sea level rise. The initiation of Laguna de la Leche correlates with a shift to wetter conditions as indicated in pollen records from the southeastern United States (e.g., Lake Tulane). This synchronicity suggests that sea level rise caused middle Holocene environmental change region-wide. Two other cores sampled from mangrove swamps in the vicinity of Laguna de la Leche indicate that a major expansion of mangroves was underway by ∼ 1700 cal yr BP.

scholarly journals Determining Extreme Still Water Levels for Design and Planning Purposes Incorporating Sea Level Rise: Sydney, Australia

Atmosphere ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 95
Author(s):  
Phil J. Watson
Keyword(s):  
Sea Level Rise ◽  
Water Level ◽  
Sea Level ◽  
Tide Gauge ◽  
Water Levels ◽  
Extreme Value Analysis ◽  
Tide Gauge Record ◽  
Value Analysis ◽  
Mean Sea Level ◽  
The Impact

This paper provides an Extreme Value Analysis (EVA) of the hourly water level record at Fort Denison dating back to 1915 to understand the statistical likelihood of the combination of high predicted tides and the more dynamic influences that can drive ocean water levels higher at the coast. The analysis is based on the Peaks-Over-Threshold (POT) method using a fitted Generalised Pareto Distribution (GPD) function to estimate extreme hourly heights above mean sea level. The analysis highlights the impact of the 1974 East Coast Low event and rarity of the associated measured water level above mean sea level at Sydney, with an estimated return period exceeding 1000 years. Extreme hourly predictions are integrated with future projections of sea level rise to provide estimates of relevant still water levels at 2050, 2070 and 2100 for a range of return periods (1 to 1000 years) for use in coastal zone management, design, and sea level rise adaptation planning along the NSW coastline. The analytical procedures described provide a step-by-step guide for practitioners on how to develop similar baseline information from any long tide gauge record and the associated limitations and key sensitivities that must be understood and appreciated in applying EVA.

scholarly journals High accuracy coastal flood mapping for Norway using LiDAR data

2019 ◽  
Author(s):  
Kristian Breili ◽  
Matthew James Ross Simpson ◽  
Erlend Klokkervold ◽  
Oda Roaldsdotter Ravndal
Keyword(s):  
At Risk ◽  
Sea Level Rise ◽  
Sea Level ◽  
Storm Surge ◽  
Coastal Flooding ◽  
High Accuracy ◽  
Mapping Method ◽  
Water Levels ◽  
Climate Services ◽  
Elevation Data

Abstract. Using new high accuracy Light Detection and Ranging elevation data we generate coastal flooding maps for Norway. Thus far, we have mapped ~ 80 % of the coast, for which we currently have data of sufficient accuracy to perform our analysis. Although Norway is generally at low risk from sea-level rise largely owing to its steep topography, the maps presented here show that on local scales, many parts of the coast are potentially vulnerable to flooding. There is a considerable amount of infrastructure at risk along the relatively long and complicated coastline. Nationwide we identify a total area of 400 km2, 105,000 buildings, and 510 km of roads that are at risk of flooding from a 200 year storm-surge event at present. These numbers will increase to 610 km2, 137,000, and 1340 km with projected sea-level rise to 2090 (95th percentile of RCP8.5 as recommended in planning). We find that some of our results are likely biased high owing to erroneous mapping (at least for lower water levels close to the tidal datum which delineates the coastline). A comparison of control points from different terrain types indicates that the elevation model has a root mean square error of 0.26 m and is the largest source of uncertainty in our mapping method. The coastal flooding maps and associated statistics are freely available, and alongside the development of coastal climate services, will help communicate the risks of sea-level rise and storm surge to stakeholders. This will in turn aid coastal management and climate adaption work in Norway.

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

2016 ◽  
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.

scholarly journals New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Scott A. Kulp ◽  
Benjamin H. Strauss
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
High Tide ◽  
Water Levels ◽  
Low Carbon ◽  
Digital Elevation ◽  
Elevation Data ◽  
Global Mean Sea Level ◽  
Elevation Model ◽  
Global Mean

Abstract Most estimates of global mean sea-level rise this century fall below 2 m. This quantity is comparable to the positive vertical bias of the principle digital elevation model (DEM) used to assess global and national population exposures to extreme coastal water levels, NASA’s SRTM. CoastalDEM is a new DEM utilizing neural networks to reduce SRTM error. Here we show – employing CoastalDEM—that 190 M people (150–250 M, 90% CI) currently occupy global land below projected high tide lines for 2100 under low carbon emissions, up from 110 M today, for a median increase of 80 M. These figures triple SRTM-based values. Under high emissions, CoastalDEM indicates up to 630 M people live on land below projected annual flood levels for 2100, and up to 340 M for mid-century, versus roughly 250 M at present. We estimate one billion people now occupy land less than 10 m above current high tide lines, including 230 M below 1 m.

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