While there is high certainty that chronic coastal hazards like floodingand erosion, are increasing due to climate change induced sea-levelrise, there is high uncertainty surrounding the timing, intensity, andlocation of future hazard impacts. Assessments that quantify theseaspects of future hazards are critical for adaptation planning under achanging climate and can reveal new insights into the drivers of coastalhazards. In particular, probabilistic simulations of future hazardimpacts can improve these assessments by explicitly quantifyinguncertainty and by better simulating dependence structures between thecomplex multivariate drivers of hazards. In this study, a regional-scaleprobabilistic assessment of climate change induced coastal hazards isconducted for the Cascadia region, USA during the 21st century. Threeco-produced hazard proxies for beach safety, erosion, and flooding arequantified to identify areas of high hazard impacts and determine hazarduncertainty under three sea-level rise scenarios. A novel chroniccoastal hazard hotspot indicator is introduced that identifies areasthat may experience significant increases in hazard impacts compared topresent day conditions. We find that Southern Cascadia and NorthernWashington have larger hazard impacts and hazard uncertainty due totheir morphologic setting. Erosional hazards, relative to beach safetyand coastal flooding, will increase the most in Cascadia during the 21stcentury under all sea-level rise scenarios. Finally, we find that hazarduncertainty associated with wave and water level variability exceeds theuncertainty associated with sea-level-rise until the end of the century.
Abstract. Megacities are predominantlyconcentrated along coastlines, making them exposed to a diverse mix ofnatural hazards. The assessment of climatic hazard risk to cities rarely hascaptured the multiple interactions that occur in complex urban systems. Wepresent an improved method for urban multi-hazard risk assessment. We thenanalyze the risk of New York City as a case study to apply enhanced methodsfor multi-hazard risk assessment given the history of exposure to multipletypes of natural hazards which overlap spatially and, in some cases,temporally in this coastal megacity. Our aim is to identify hotspots ofmulti-hazard risk to support the prioritization of adaptation strategies thatcan address multiple sources of risk to urban residents. We usedsocioeconomic indicators to assess vulnerabilities and risks to threeclimate-related hazards (i.e., heat waves, inland flooding and coastal flooding) at high spatial resolution.The analysis incorporates local experts' opinions to identify sources ofmulti-hazard risk and to weight indicators used in the multi-hazard riskassessment. Results demonstrate the application of multi-hazard riskassessment to a coastal megacity and show that spatial hotspots ofmulti-hazard risk affect similar local residential communities along thecoastlines. Analyses suggest that New York City should prioritize adaptationin coastal zones and consider possible synergies and/or trade-offs tomaximize impacts of adaptation and resilience interventions in the spatiallyoverlapping areas at risk of impacts from multiple hazards.
more » « less- Award ID(s):
- 1737626
- PAR ID:
- 10110654
- Date Published:
- Journal Name:
- Natural Hazards and Earth System Sciences
- Volume:
- 18
- Issue:
- 12
- ISSN:
- 1684-9981
- Page Range / eLocation ID:
- 3363 to 3381
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Regional scale assessments of future chronic coastal hazard impacts are critical tools for adaptation planning under a changing climate. Probabilistic simulations of hazard impacts can improve these assessments by explicitly attempting to quantify uncertainty and by better simulating dependence between complex multivariate drivers of hazards. In this study, probabilistic future timeseries of total water levels (TWLs) are generated from a stochastic climate emulator (TESLA; Anderson et al., 2019) for the Cascadia region, USA for use in a chronic hazard impact assessment. This assessment focuses on three hazard metrics: collision, overtopping, and beach safety, and also introduces a novel hotspot indicator to identify areas that may experience dramatic changes in hazard impacts compared to present day conditions. Results are presented for a subset of the Cascadia region (Rockaway Beach Littoral Cell, Oregon) to demonstrate the power of the probabilistic impact assessment approach. The results highlight how useful spatially varying, scenario-based hazard impacts assessments and hotspot indicators are for identifying which areas and types of hazards may require increased adaptation support. This approach enables us to piece apart the relative uncertainty of hazards as driven by SLR versus natural variability (caused by variation in climate, weather, and hydrodynamic drivers).more » « less
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Abstract Extreme weather-related events are showing how infrastructure disruptions in hinterlands can affect cities. This paper explores the risks to city infrastructure services including transportation, electricity, communication, fuel supply, water distribution, stormwater drainage, and food supply from hinterland hazards of fire, precipitation, post-fire debris flow, smoke, and flooding. There is a large and growing body of research that describes the vulnerabilities of infrastructures to climate hazards, yet this work has not systematically acknowledged the relationships and cross-governance challenges of protecting cities from remote disruptions. An evidence base is developed through a structured literature review that identifies city infrastructure vulnerabilities to hinterland hazards. Findings highlight diverse pathways from the initial hazard to the final impact on an infrastructure, demonstrating that impacts to hinterland infrastructure assets from hazards can cascade to city infrastructure. Beyond the value of describing the impact of hinterland hazards on urban infrastructure, the identified pathways can assist in informing cross-governance mitigation strategies. It may be the case that to protect cities, local governments invest in mitigating hazards in their hinterlands and supply chains.
- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.5194/nhess-18-3363-2018
