With Hurricane Laura hitting Louisiana and Texas as an “extremely dangerous” Category 4 storm and wildfires threatening the western United States, millions of Americans face the complex risks of a natural disaster in the midst of a pandemic.
Overcrowded grocery stores and emergency shelters are potential concerns.
The steps people normally take to prepare for a severe storm or to evacuate can contradict public health recommendations to protect themselves and others from COVID-19. That is what millions of people were facing when Hurricane Laura intensified in the Gulf of Mexico. More than half a million people were under evacuation orders, including the cities of Galveston, Beaumont and Port Arthur, Texas.
My urban resilience lab at Texas A&M University has been examining the interactions between urban infrastructure, systems, and people in disasters. At the start of the COVID-19 pandemic, we launched a study on the effect of the pandemic on urban systems during a natural disaster, applying methods similar to those we used during an extensive investigation into Hurricane Harvey, which flooded Houston in August 2017. .
Our research shows that compound disasters have complex ramifications. At the intersection of a natural hazard and a pandemic there is a decision process riddled with contradictions.
STORM PREPAREDNESS AND EVACUATIONS INCREASE RISKS
During the three days leading up to Hurricane Harvey, the number of visits to supermarkets and gas stations in the Houston area increased between 50% and 100%. People didn't think twice about running to the store.
As Hurricane Laura made its way off the Louisiana and Texas coasts, residents found themselves in a very different situation. The rise in COVID-19 illnesses and deaths across the South during the summer meant that people were encouraged to self-quarantine and limit their social contact to prevent transmission of the coronavirus. They could still wear masks in stores, but keeping the recommended distance of two meters becomes more difficult when stores get crowded. It means spending more time waiting with others in lines and jostling in the hallways. Research shows that both the amount of virus and the length of time a person is exposed to it have an impact on whether and how severely they become infected.
An even more onerous complication, both for authorities and residents, is evacuation.
The decision to evacuate even in the face of a single hazard, be it a wildfire or a hurricane, is a difficult one. Sheltering in one place can mean life-threatening conditions, prolonged power outages, and interrupted access to critical facilities. Evacuate means leaving home and possibly animals behind to an uncertain destination.
That gets even more complicated when an emergency shelter is the best option, but staying in one can mean a higher risk of being exposed to someone infected with the coronavirus.
WHICH AREAS ARE MOST VULNERABLE?
Authorities evaluate many variables when deciding between mandatory and voluntary evacuations. Faced with a pandemic, they now also have to think about disease transmission, and not just in individual emergency shelters, but on a larger scale as well. When a large population moves from an area with a high rate of spread of the disease to a less affected area, it can put the local population at greater risk.
Using data on social vulnerability, pandemic risk, and hazard probability, my lab created an interactive map that identifies sources of vulnerability. The goal is to enable disaster response managers and decision makers to recognize the compound risks posed by the confluence of the pandemic and any natural hazards.
The Composite Hazard Risk Index takes into account local social, physical and pandemic risks, allowing each county or community to make informed decisions. It also generates warnings for vulnerable groups, such as the elderly and low-income communities, who may be at disproportionate risk of infection.
We found several counties with significantly high levels of compound risks.