High accuracy coastal flood mapping for Norway using LiDAR 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.

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High-accuracy coastal flood mapping for Norway using lidar data

Natural Hazards and Earth System Science ◽

10.5194/nhess-20-673-2020 ◽

2020 ◽

Vol 20 (2) ◽

pp. 673-694

Author(s):

Kristian Breili ◽

Matthew James Ross Simpson ◽

Erlend Klokkervold ◽

Oda Roaldsdotter Ravndal

Keyword(s):

At Risk ◽

Sea Level Rise ◽

Sea Level ◽

Storm Surge ◽

Climate Adaptation ◽

Coastal Flooding ◽

High Accuracy ◽

Water Levels ◽

Land Uplift ◽

Climate Services

Abstract. Using new high-accuracy light detection and ranging (lidar) 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 and land uplift due to glacial isostatic adjustment, 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 adaptation work in Norway.

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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 ◽

10.3390/w13040545 ◽

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.

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High-Resolution Coastal Elevation Data: The Key to Planning for Storm Surge and Sea Level Rise

Geospatial Technologies and Homeland Security - The GeoJournal Library ◽

10.1007/978-1-4020-8507-9_11 ◽

2008 ◽

pp. 229-240

Author(s):

Mark Monmonier

Keyword(s):

High Resolution ◽

Sea Level Rise ◽

Sea Level ◽

Storm Surge ◽

Elevation Data ◽

And Sea Level

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

Nature Communications ◽

10.1038/s41467-019-12808-z ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 70

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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Response of Storm-Related Extreme Sea Level along the U.S. Atlantic Coast to Combined Weather and Climate Forcing

Journal of Climate ◽

10.1175/jcli-d-19-0551.1 ◽

2020 ◽

Vol 33 (9) ◽

pp. 3745-3769 ◽

Cited By ~ 1

Author(s):

Jianjun Yin ◽

Stephen M. Griffies ◽

Michael Winton ◽

Ming Zhao ◽

Laure Zanna

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Storm Surge ◽

Gulf Coast ◽

Climate Modeling ◽

Atlantic Coast ◽

The United States ◽

Coastal Flooding ◽

Meridional Overturning Circulation ◽

The U.S

AbstractStorm surge and coastal flooding caused by tropical cyclones (hurricanes) and extratropical cyclones (nor’easters) pose a threat to communities along the Atlantic coast of the United States. Climate change and sea level rise are altering the statistics of these extreme events in a rather complex fashion. Here we use a fully coupled global weather/climate modeling system (GFDL CM4) to study characteristics of extreme daily sea level (ESL) along the U.S. Atlantic coast and their response to global warming. We find that under natural weather processes, the Gulf of Mexico coast is most vulnerable to storm surge and related ESL. New Orleans is a striking hotspot with the highest surge efficiency in response to storm winds. Under a 1% per year atmospheric CO2 increase on centennial time scales, the anthropogenic signal in ESL is robust along the U.S. East Coast. It can emerge from the background variability as soon as in 20 years, or even before global sea level rise is taken into account. The regional dynamic sea level rise induced by the weakening of the Atlantic meridional overturning circulation facilitates this early emergence, especially during wintertime coastal flooding associated with nor’easters. Along the Gulf Coast, ESL is sensitive to the modification of hurricane characteristics under the CO2 forcing.

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Predicting Sea-Level Rise in Al Hamra Development, Ras Al Khaimah, UAE

International Journal of Sustainable Water and Environmental Systems ◽

10.5383/swes.7.02.004 ◽

2015 ◽

Vol 07 (2) ◽

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Information Needs ◽

Arabian Gulf ◽

Pilot Project ◽

Water Levels ◽

Eastern Coast ◽

Future Research ◽

Accurate Information ◽

Elevation Data

The Al Hamra development in the emirate of Ras Al Khaimah is situated along the south-eastern coast of the Arabian Gulf. The development fronts the Gulf along a 5 km. stretch of sandy beach and, as it includes 5 hotels, numerous villas and condos, represents a significant investment. Such an investment requires long-term strategies to minimize risk from sea level rise. As IPCC reports continue to be updated with new information, predictions of sea level rise have been revised upward. In order to plan for the protection of these, and other developments, accurate information needs to be supplied to those involved in planning adaptation strategies. This paper seeks to quantify and map the potential area subject to inundation up to the year 2099. Using the highest inundation scenario, a GIS map of inundation will be created. Other factors, such as high tides, storm surge and extreme wave events will see water levels increased beyond the predicted sea level scenarios indicating greater risk of flooding. This project will use LiDAR data in a GIS environment to provide the most accurate elevation data. Other layers showing buildings assist in visualizing future vulnerability to sea level rise. This coastline is heavily developed with construction underway for more resort developments. As the risk from sea level rise evolves over a long time period, planners require accurate information that can be easily updated in order to react to revised predictions. This paper represents a pilot project as future research is planned to examine the entire 65km coastline of Ras Al Khaimah

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Coastal flooding protection will change salt-marsh sedimentation dynamics

10.5194/egusphere-egu21-1639 ◽

2021 ◽

Author(s):

Davide Tognin ◽

Andrea D'Alpaos ◽

Marco Marani ◽

Luca Carniello

Keyword(s):

Salt Marsh ◽

Sea Level Rise ◽

Sea Level ◽

Storm Surge ◽

Sedimentation Rate ◽

Urban Areas ◽

Storm Surges ◽

Venice Lagoon ◽

Water Levels ◽

Sedimentation Dynamics

Coastal wetlands lie at the interface between submerged and emerged environments and therefore represent unique yet delicate ecosystems. Their existence, resulting from complex interactions between hydrodynamics and sediment dynamics, is challenged by increasing rates of sea-level rise, lowered fluvial sediment input as well as an increasing anthropogenic pressure. The future survival of these peculiar morphologies is becoming even more complicated, because of the construction and planning of coastal defence structures designed to protect urban areas from flooding. Important examples are the flood protection systems built to protect New Orleans (USA), the river Scheldt Estuary (The Netherlands) and Venice (Italy). In this context, understanding the physical processes on which coastal marshes are grounded and how engineering measures can alter them is of extreme importance in order to plan conservation interventions.To understand marsh sedimentation dynamics in flood-regulated environments, we investigated through field observations and modelling the effect of the storm-surge barrier designed to protect the city of Venice, the so-called Mo.S.E. system, which has in fact become operational since October 2020.Sedimentation measurements in different salt marshes of the Venice lagoon carried out in the period October 2018-October 2020 show that more than 70% of yearly sedimentation accumulates during storm-surge conditions, despite their short duration. Moreover, the sedimentation rate displays a highly non-linear increase with marsh inundation intensity, due to the interplay between higher water levels and greater suspended sediment concentration. Barrier operations during storm surges to avoid flooding of urban areas will reduce water levels and marsh inundation. Therefore, we computed sedimentation in a flood-regulated scenario for the same observation period, using the relation we obtained between tidal forcing and sedimentation rate. Our results show that some occasional closures during intense storm surges (70 hours/year on average) suffice to reduce the yearly sedimentation of the same order of magnitude of the relative sea-level rise rate experienced by the Venice lagoon during the last century (2.5 mm/y).We conclude that storm-surge barrier operations can dangerously reduce salt-marsh vertical accretion rate, thus challenging wetland survival in face of increasing sea-level rise.

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The impact of sea level rise on storm surge water levels in the northern part of the German Bight

Coastal Engineering ◽

10.1016/j.coastaleng.2014.12.002 ◽

2015 ◽

Vol 96 ◽

pp. 118-131 ◽

Cited By ~ 55

Author(s):

A. Arns ◽

T. Wahl ◽

S. Dangendorf ◽

J. Jensen

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Storm Surge ◽

German Bight ◽

Water Levels ◽

The Impact

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A Study on Coastal Flooding and Risk Assessment under Climate Change in Mid-Western Coast of Taiwan

10.20944/preprints201703.0172.v1 ◽

2017 ◽

Author(s):

Tai-Wen Hsu ◽

Dong-Sin Shih ◽

Chi-Yu Li ◽

Yuan-Jyh Lan ◽

Yu-Chen Lin

Keyword(s):

Climate Change ◽

Risk Assessment ◽

Sea Level Rise ◽

Sea Level ◽

Storm Surge ◽

Coastal Flooding ◽

Risk Level ◽

Western Coast ◽

Wave Condition ◽

The Impact

This study integrated coastal-watershed models and combined a risk assessment method to develop a methodology to investigate the impact resulting from coastal disasters under climate change. The mid-western coast of Taiwan suffering from land subsidence was selected as the demonstrative area for the vulnerability analysis based on prediction of sea level rise (SLR), wave run-up, overtopping, and coastal flooding under the scenarios of 2020 to 2039. Database from tidal gauges and satellite images were used to analyze sea level rise using EEMD (Ensemble Empirical Mode Decomposition). Extreme wave condition and storm surge were estimated by numerical simulation using WWM (Wind Wave Model) and POM (Princeton Ocean Model). Coastal inundation was then simulated via WASH123D watershed model. The risk map of study areas based on the analyses of vulnerability and disaster were established using the AHP (Analytic Hierarchy Process) technique. Predictions of sea level rise, the maximum wave condition and storm surge under the scenarios of 2020 to 2039 are presented. The results indicate that the sea level at the mid-western coast of Taiwan will rise in an average of 5.8 cm, equivalent to a rising velocity of 2.8 mm/year. The analysis indicates that Wuqi, Lukang, Mailiao, and Taixi townships are susceptive, low resistant and low resilient, and reaches the high risk level. The assessment provides that important information for making adaption policy in the mid-western coast of Taiwan.

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