Spatial Accessibility
2023-7-22
Spatial Accessibility Analysis of Emergency Shelters with a Consideration of Sea Level Rise in Northwest Florida
This study analyzes the impact of sea level rise on the accessibility of hurricane shelters in 4 coastal counties in Northwest Florida using storm surge modeling and floating catchment area methods.
Abstract:
Hurricane-induced storm surge and flooding often lead to the closures of evacuation routes, which can be disruptive for the victims trying to leave the impacted region. This problem becomes even more challenging when we consider the impact of sea level rise that happens due to global warming and other climate-related factors. As such, hurricane-induced storm surge elevations would increase nonlinearly when sea level rise lifts, flooding access to highways and bridge entrances, thereby reducing accessibility for affected census block groups to evacuate to hurricane shelters during hurricane landfall. This happened with the Category 5 Hurricane Michael which swept the east coast of Northwest Florida with long-lasting damage and impact on local communities and infrastructure. In this paper, we propose an integrated methodology that utilizes both sea level rise (SLR) scenario-informed storm surge simulations and floating catchment area models built in Geographical Information Systems (GIS). First, we set up sea level rise scenarios of 0, 0.5, 1, and 1.5 m with a focus on Hurricane Michael’s impact that led to the development of storm surge models. Second, these storm surge simulation outputs are fed into ArcGIS and floating catchment area-based scenarios are created to study the accessibility of shelters. Findings indicate that rural areas lost accessibility faster than urban areas due to a variety of factors including shelter distributions, and roadway closures as spatial accessibility to shelters for offshore populations was rapidly diminishing. We also observed that as inundation level increases, urban census block groups that are closer to the shelters get extremely high accessibility scores through FCA calculations compared to the other block groups. Results of this study could guide and help revise existing strategies for designing emergency response plans and update resilience action policies.
Summary:
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Background
- Hurricane storm surge can flood roads and cut off access to hurricane shelters
- Sea level rise exacerbates storm surge impacts
- Studied impact of Hurricane Michael on 4 NW Florida coastal counties
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Methods
- Simulated storm surge for Hurricane Michael with 0-1.5 m sea level rise scenarios
- Calculated accessibility to shelters using E2SFCA and 3SFCA methods
- Compared results statistically between methods
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Results
- Increasing sea level rise expanded inundation areas nonlinearly
- Rural areas lost accessibility faster than urban areas
- E2SFCA showed uneven score changes with sea level rise
- 3SFCA gave smoother distribution of scores
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Conclusions
- Sea level rise reduces hurricane shelter accessibility, especially in rural areas
- E2SFCA better for overall assessment, 3SFCA better for demand details
- Results can inform hurricane evacuation and emergency planning
Study Questions and Answers
| Question | Answer |
|---|---|
| What was the main goal? | Analyze impact of sea level rise on hurricane shelter accessibility |
| What location was studied? | 4 coastal counties in NW Florida |
| How was accessibility modeled? | Using E2SFCA and 3SFCA methods with sea level rise scenarios |
| What was a key finding? | Increasing sea level rise reduces shelter accessibility |
| How can the results be used? | To improve hurricane evacuation and emergency planning |
DOI: 10.3390/su151310263