Evacuation planning for plausible worst case inundation scenarios in Honolulu, Hawaii

2015 ◽  
Vol 13 (2) ◽  
pp. 93 ◽  
Author(s):  
Karl Kim, PhD ◽  
Pradip Pant, PhD ◽  
Eric Yamashita, MURP

Honolulu is susceptible to coastal flooding hazards. Like other coastal cities, Honolulu's long-term economic viability and sustainability depends on how well it can adapt to changes in the natural and built environment. While there is a disagreement over the magnitude and extent of localized impacts associated with climate change, it is widely accepted that by 2100 there will be at least a meter in sea level rise (SLR) and an increase in extreme weather events. Increased exposure and vulnerabilities associated with urbanization and location of human activities in coastal areas warrants serious consideration by planners and policy makers.This article has three objectives. First, flooding due to the combined effects of SLR and episodic hydrometeorological and geophysical events in Honolulu are investigated and the risks to the community are quantified. Second, the risks and vulnerabilities of critical infrastructure and the surface transportation system are described. Third, using the travel demand software, travel distances and travel times for evacuation from inundated areas are modeled.Data from three inundation models were used. The first model simulated storm surge from a category 4 hurricane similar to Hurricane Iniki which devastated the island of Kauai in 1992. The second model estimates inundation based on five tsunamis that struck Hawaii. A 1-m increase in sea level was included in both the hurricane storm surge and tsunami flooding models. The third model used in this article generated a 500-year flood event due to riverine flooding. Using a uniform grid cell structure, the three inundation maps were used to assess the worst case flooding scenario. Based on the flood depths, the ruling hazard (hurricane, tsunami, or riverine flooding) for each grid cell was determined. The hazard layer was analyzed with socioeconomic data layers to determine the impact on vulnerable populations, economic activity, and critical infrastructure. The analysis focused both on evacuation needs and the critical elements of the infrastructure system that are needed to ensure effective response and recovery in the advent of flooding.This study shows that the coastal flooding will seriously affect the economy and employment. Extreme flooding events could affect 38 percent of the freeways, 44 percent of the highways, 69 percent of the arterial roads, and 40 percent of the local streets in the area examined. Approximately 80 percent of the economy and 76 percent of the total employment in the urban core of Honolulu is exposed to flooding. Evacuation modeling, shelter accessibility, and travel time to shelter analyses revealed that there is a significant shortage in sheltering options, as well as increases in travel times and distances as inundation depth increases. The findings are useful for evacuation and shelter planning for extreme coastal events, as well as for climate change adaptation planning in Honolulu. Recommendations for emergency responders as well as those interested in the integration of long-term SLR and low probability, high consequence coastal hazards are included. The study shows how to integrate travel demand modeling across multiple hazards and threats related to evacuating, sheltering, and disaster risk reduction.

Author(s):  
Tai-Wen Hsu ◽  
Dong-Sin Shih ◽  
Chi-Yu Li ◽  
Yuan-Jyh Lan ◽  
Yu-Chen Lin

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.


Author(s):  
Xiufeng Yang ◽  
Dale Kerper ◽  
Shubhra Misra ◽  
James Stear ◽  
Tao Shen ◽  
...  

Storm surge is a major natural hazard to the construction and operation of infrastructure projects in shallow and gently sloping coastal areas such as the northeastern part of the Caspian Sea. Up-surge events cause significant coastal flooding, while down-surge events disrupt marine transportation by constraining safe navigable water depths. Coastal developments therefore have to achieve a judicious balance of these conflicting constraints. Further, the unpredictability of long-term and intra-annual Mean Sea Level (MSL) variability as well as periodic freeze-up and break-up due to ice formation in this part of the Caspian Sea complicate a robust and unequivocal basis for defining storm surge hazards.


Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 545
Author(s):  
Alexis K. Mills ◽  
Peter Ruggiero ◽  
John P. Bolte ◽  
Katherine A. Serafin ◽  
Eva Lipiec

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.


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.


Author(s):  
Yako Harada ◽  
Yukihisa Matsumoto ◽  
Kazuho Morishita ◽  
Nobuyuki Oonishi ◽  
Kazuyoshi Kihara ◽  
...  

The vertical telescopic breakwater(VTB), which is a new breakwater that permits the navigation of ships, remain at the bottom of the sea during calm and rise to the surface during tsunamis or storm surges. Kawai et al. (2017) and Arikawa et al. (2019) found that it is effective not only for swell waves, but also for long-period waves simulating tsunamis and storm surges by previous experiments and numerical analyses. However, there have been few studies on the performance of VTB by numerical calculations in actual ports using actual typhoons. In addition, sea levels and changes in characteristics of typhoon due to climate change are predicted to occur; hence, we are concerned about the damage in all quarters caused by storm surge inundation, especially at Tokyo. Therefore, in this study, we used hypothetical typhoons under worst-case scenarios and quantitatively evaluated the protection performance of VTB against hypothetical typhoons with different aperture rates of VTB in Tokyo Bay by the numerical simulation.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/qof5ixKqIiA


Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3090
Author(s):  
Sergio B. Jiménez-Hernández ◽  
Ofelia Pérez Montero ◽  
Eustorgio Meza ◽  
Yunior R. Velázquez ◽  
Juan R. Castellanos ◽  
...  

This paper presents a coastal migration index (CMI) useful for decision-making in the current scenario of sea-level rise (SLR) due to climate change. The CMI includes coastal human population density, degree of urbanization, and coastal-flooding penetration. Quantitative and qualitative statistical techniques and the geographic information system ArcGIS View 9.0 were used. Further, a panel of fifteen international experts in coastal management issues was consulted to establish and validate the CMI. Results led to three index components based on 22 indicators. CMI was applied in the state of Tamaulipas, Mexico and in Santiago de Cuba province, Cuba. According to CMI estimates, the risk levels associated with SLR for human settlements analyzed in Mexico and Cuba were 5.3% and 11.0%, respectively. The most severely affected communities will require resettlement. Meanwhile, the CMI determined that 15.8% of the Mexican territory studied will be able to withstand the effects of SLR through the management of engineering works that will protect human settlements. The CMI determined that 79.0%, in the case of Tamaulipas, as well as 89.0% of the Cuban territory, will not require new policies or guidelines to promote conservation and protection of coastal natural resources. Lastly, the method used allowed for creation of a CMI stoplight map useful to coastal decision-makers to adopt sound management actions.


2015 ◽  
Vol 15 (3) ◽  
pp. 527-535 ◽  
Author(s):  
F. Raicich

Abstract. Sea level observations made in the Venice Lagoon between 1751 and 1792 have been recovered, consisting of two time series of daily data on high and low waters in Venice and Chioggia. From comparisons with modern observations, the quality of the 18th century data appears to be good enough to allow a useful analysis. A composite time series of daily mean sea level is obtained by merging the 18th century data and 1872–2004 observations in Venice Punta della Salute. The absence of reliable information on vertical references prevents the connection of the two 18th century time series with each other and with modern observations. However, daily sea level anomalies relative to the mean sea level enable us to recognize storm surge events that appear to occur more frequently in the second half of the 18th century than in the late 19th and 20th centuries, particularly during the 1751–1769 period. The record-breaking storm surge of 4 November 1966 turns out to be a remarkable event even in comparison to the events extracted from the 18th century time series. Further work is required to fill the gap between the old and modern observations.


Author(s):  
Kristian Breili ◽  
Matthew James Ross Simpson ◽  
Erlend Klokkervold ◽  
Oda Roaldsdotter Ravndal

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.


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.


2020 ◽  
Author(s):  
Pau Luque Lozano ◽  
Lluís Gómez-Pujol ◽  
Marta Marcos ◽  
Alejandro Orfila

<p>Sea-level rise induces a permanent loss of land with widespread ecological and economic impacts, most evident in urban and densely populated areas. The eventual coastline retreat combined with the action of waves and storm surges will end in more severe damages over coastal areas. These effects are expected to be particularly significant over islands, where coastal zones represent a relatively larger area vulnerable to marine hazards.</p><p>Managing coastal flood risk at regional scales requires a prioritization of resources and socioeconomic activities along the coast. Stakeholders, such as regional authorities, coastal managers and private companies, need tools that help to address the evaluation of coastal risks and criteria to support decision-makers to clarify priorities and critical sites. For this reason, the regional Government of the Balearic Islands (Spain) in association with the Spanish Ministry of Agriculture, Fisheries and Environment has launched the Plan for Climate Change Coastal Adaptation. This framework integrates two levels of analysis. The first one relates with the identification of critical areas affected by coastal flooding and erosion under mean sea-level rise scenarios and the quantification of the extent of flooding, including marine extreme events. The second level assesses the impacts on infrastructures and assets from a socioeconomic perspective due to these hazards.</p><p>In this context, this paper quantifies the effects of sea-level rise and marine extreme events caused by storm surges and waves along the coasts of the Balearic Islands (Western Mediterranean Sea) in terms of coastal flooding and potential erosion. Given the regional scale (~1500 km) of this study, the presented methodology adopts a compromise between accuracy, physical representativity and computational costs. We map the projected flooded coastal areas under two mean sea-level rise climate change scenarios, RCP4.5 and RCP8.5. To do so, we apply a corrected bathtub algorithm. Additionally, we compute the impact of extreme storm surges and waves using two 35-year hindcasts consistently forced by mean sea level pressure and surface winds from ERA-Interim reanalysis. Waves have been further propagated towards the nearshore to compute wave setup with higher accuracy. The 100-year return levels of joint storm surges and waves are used to map the spatial extent of flooding in more than 200 sandy beaches around the Balearic Islands by mid and late 21st century, using the hydrodynamical LISFLOOD-FP model and a high resolution (2 m) Digital Elevation Model.</p>


Sign in / Sign up

Export Citation Format

Share Document