View of strom surge flooding in New Orleans after Hurricane Katrina (Paul Morse/The White House)
When Hurricane Zeta made landfall in Louisiana Wednesday this past October, it was the 25th storm for the 2020 Atlantic Hurricane season. 11 of these storms reached the US breaking a 104 year old record. Zeta made landfall as a Category 2 hurricane. While hurricanes fall on a category scale from 1-5, 1 being the least damaging and 5 being the most, Zeta still sustained winds ranging from 96-110 mph, which still has a devastating impact for those in the storm’s path. For coastal communities, a hurricane means strong winds, heavy rains, and flooding, that leads to property damages and even death. Flooding from hurricanes is even more dangerous to communities than winds.
What causes floods that put entire communities under water? It’s not just rainfall It turns out storm surges drive coastal flooding from hurricanes. Storm surge is a temporary water level from the interaction between the atmosphere and the ocean which pushes surface waters toward the eye of the storm, and along the path of the storm. As hurricanes, also referred to as cyclones or typhoons, make landfall, they don’t just dump a bunch of rain, they bring seawater too, flooding areas with water levels reaching 20 feet or higher.
Multiple factors affect the height of storm surges including: whether it is high or low tide, the intensity of the storm, storm size, and physical characteristics of the coastline where the storm makes landfall. In 2005, a 25-28 foot storm surge made Hurricane Katrina one of the deadliest hurricanes in history, Damage from the surge extended miles inland. The storm killed 1200 people and caused $75 billion in damages.
Storm surges change lives long after the waters have retreated. People face the cost of rebuilding homes and businesses from the ground up in the aftermath of these devastating storms. Families face displacement.Damage to infrastructure can make rebuilding an even bigger challenge. During Hurricane Maria, the storm destroyed infrastructure and supply lines connecting Puerto Rico to the mainland United States, and with a lax relief effort the island is still recovering.
As climate change intensifies, so will the frequency and severity of hurricanes and the storm surges. Just as storm surges can differ from storm to storm, the impacts of hurricanes and storm surges can differ, both environmentally and socially, throughout the world. In this beat I will look at the impacts and responses to storm surges around the world, which will help prepare for future full storm surges and climate change.