Impact of Coastal Hazards on Residents’ Spatial Accessibility to Health Services

Abstract

The mobility of residents and their access to essential services can be highly affected by transportation network closures that occur during and after coastal hazard events. Few studies have used geographic information systems coupled with infrastructure vulnerability models to explore how spatial accessibility to goods and services shifts after a hurricane. Models that explore spatial accessibility to health services are particularly lacking. This study provides a framework to examine how the disruption of transportation networks during and after a hurricane can impact a resident's ability to access health services over time. Two different bridge closure conditions-inundation and structural failure-along with roadway inundation are used to quantify post-hurricane accessibility at short-and long-term temporal scales. Inundation may close a bridge for hours or days, but a structural failure may close a route for weeks or months. Both forms of closure are incorporated using probabilistic vulnerability models coupled with GIS-based models to assess spatial accessibility in the aftermath of a coastal hazard. Harris County, an area in Southeastern Texas prone to coastal hazards, is used as a case study. The results indicate changes in the accessibility scores of specific areas depending on the temporal scale of interest and intensity of the hazard scenario. Sociodemographic indicators are also examined for the study region, revealing the populations most likely to suffer from lack of accessibility. Overall, the presented framework helps to understand how both short-

Estimating road network accessibility during a hurricane evacuation: A case study of hurricane Irma in Florida

“…The derived spatial maps of the road congestion level can be used by transportation and emergency management researchers and practitioners for further analysis such as network performance analysis to provide operational and managerial insights. Applications in other fields such as understanding the impacts of urban flooding on neighborhoods' health care access (Balomenos et al, 2019) can benefit from the results as well. In addition, the sensitivity analysis suggests that the choice of an aggressive behavioral response curve might be worthwhile to be considered in the evacuation demand modeling and decision-making process-and certainly should be implemented along with other strategies such as a staged evacuation plan-as it could lead to more people leaving vulnerable areas before the arrival of a hurricane in spite of putting a burden on the road network.…”

“…Such information could be obtained by analyzing mobile phone positioning data. Similarly, the road network may undergo significant changes during an evacuation-some roads might be closed and counterflow might be established (Dow & Cutter, 2002;Balomenos et al, 2019). Future steps of this study should include scenario-based network analysis to investigate future network performances coupled with projected population, hurricane, and road network availability.…”

Thresholds in Road Network Functioning on US Atlantic and Gulf Barrier Islands

“…Road network disruptions—mechanisms that cause reductions in mobility or increases in the costs necessary to maintain the desired levels of mobility (Markolf et al., 2019)—are common on barrier islands during hurricanes, tropical storms, and nor'easters (Dolan & Lins, 2000; Hardin et al., 2012; Krynock et al., 2005; Nordstrom, 2004; Nordstrom & Jackson, 1995; Spanger‐Siegfried et al., 2014; Velasquez‐Montoya et al., 2021), and also occur as a result of king tides, sea‐level anomalies, groundwater flooding, or other factors that lead to nuisance or “sunny day” flooding (Fant et al., 2021; Hino et al., 2019; Housego et al., 2021; Jacobs et al., 2018; Moftakhari et al., 2018, 2015, 2017; Praharaj et al., 2021). Road disruptions can lead to major socio‐economic impacts, isolating neighborhoods, compromising evacuation, and preventing people from accessing critical services (Balomenos et al., 2019; Dong, Esmalian, et al., 2020; Jenelius & Mattson, 2012; Spanger‐Siegfried et al., 2014; Suarez et al., 2005). The maintenance and restoration of other critical systems—electricity, water supply, communications—often depends on a functioning road system (Chang, 2016; Johansen & Tien, 2018; Mattson & Jenelius, 2015; Nicholson & Du, 1997).…”

Thresholds in road network functioning on US Atlantic and Gulf barrier islands

“…Road network disruptions -mechanisms that cause reductions in mobility or increases in the costs necessary to maintain the desired levels of mobility (Markolf et al, 2019) -are common on barrier islands during hurricanes, tropical storms, and nor'easters (Dolan & Lins, 2000;Hardin et al, 2012;Krynock et al, 2005;Nordstrom, 2004;Nordstrom & Jackson, 1995;Spanger-Siegfried et al, 2014;Velasquez-Montoya et al, 2021), and also occur as a result of king tides, sea-level anomalies, groundwater flooding, or other factors that lead to nuisance or "sunny day" flooding (Fant et al, 2021;Hino et al, 2019;Housego et al, 2021;Jacobs et al, 2018;Moftakhari et al, 2015Moftakhari et al, , 2017Moftakhari et al, , 2018Praharaj et al, 2021). Road disruptions can lead to major socio-economic impacts, isolating neighborhoods, compromising evacuation, and preventing people from accessing critical services (Balomenos et al, 2019;Dong et al, 2020a;Jenelius & Mattson, 2012;Spanger-Siegfried et al, 2014;Suarez et al, 2005). The maintenance and restoration of other critical systems -electricity, water supply, communications -often depends on a functioning road system (Chang, 2016;Johansen and Tien, 2018;Mattson & Jenelius, 2015;Nicholson & Du, 1997).…”