On the morning of August 29 2005, one of the deadliest Atlantic hurricanes hit the US Gulf Coast. With sustained winds of up to 140 mph, Hurricane Katrina killed over 1,800 people and caused $160 billion worth of damage.

The government at the time was criticised for its slow response, particularly its failure to involve local communities in decisions about preparing for and responding to the disaster. Almost 15 years to the day, another major storm bore down on the region. Half a million people in Texas and Louisiana evacuated to escape Hurricane Laura’s “unsurvivable” storm surge and, at the time of writing, and at least six people have been killed.

I study natural disasters in order to better understand how to save lives. One of the most important strategies for reducing the risk to everyone in a community is to engage with local people at every stage of decision making.

Communities in disaster-prone regions have developed strategies over generations for dealing with extreme weather. They’re more likely to spot the warning seasons early and know how best to respond.

The impacts of natural disasters can have a lasting effect on the lives of those in affected regions too, as anyone who has lived in New Orleans over the last two decades could tell you. It’s vital the input of these communities is taken into consideration if there is to be lasting trust in the institutions that organise disaster preparation and relief efforts.

Early warnings

Some of my research has compared how academic experts and people living in disaster-prone areas think differently about these events. While experts studying natural disasters tend to focus on intense but infrequent events like tsunamis, there are communities around the world which have adapted to milder but more common problems like flooding.

We wanted to visit communities in both the UK and Japan, to compare how their community leaders and engineers developed counter measures to protect their local areas. These were categorised as “soft” countermeasures, like evacuation plans and early warning systems, and as “hard” solutions, such as flood defences and embankments.

Communities facing high-impact but low-frequency disasters, like tsunamis in Japan, tend to have strategies that prevent or reduce the scale of the damage with hard engineering, such as sea walls. For communities subject to low-impact but high-frequency hazards like flooding, such as those we studied in the UK, adaptation is what characterises most countermeasures, including community networks that keep vulnerable people alert to any threat.

The Joukumachi community in Hita City of Oita Prefecture, Japan was affected by torrential rain in 2017 and 2018. Though government measures were slowly enacted, with some residents evacuated to shelters and higher ground, it was interventions by local residents that allowed the community to recognise the risks early and respond quickly.

Most notably, local people people used handmade rain gauges with loudspeakers that could broadcast alerts to monitor the approaching danger. This early warning system helped people prepare before the government could launch a response.

Preparing for the future

But what makes an effective response to future disasters? Our research in Sturmer, a flood-prone village in Essex, England, showed that dedicated community organising is the best defence.

Sturmer was swamped with heavy rainfall in 2001 and 2014, causing floods that wreaked a lot of damage. But these events paled in comparison to the catastrophic storm surges that devastated the region in 1953. As climate change threatens more severe rain storms in the future, the community has developed its own ways to stay prepared.

Read more: 1953 storm surge: how Britain's worst natural disaster kicked off the debate on climate change

Following the floods in 2014, a flood action group was formed in the village. The group is led by members of the community and it communicates flood risk through meetings, magazines and flyers. To keep local residents aware of flood alerts, some in the group are responsible for constantly checking the daily weather forecast, as well as flood depth gauges deployed in the stream. When flooding seems imminent, the houses most at risk are provided with portable flood gates that can be deployed as and when they’re needed.

This ongoing, bottom-up approach looks very different to a reactive disaster response led by central government agencies – which are often based far away. Even the best examples of top-down management are unlikely to possess the breadth of experience and local knowledge that makes communities so effective at preparing for natural disasters.

Central governments must learn from them and ask how best they can aid relief and recovery, rather than try and impose a one-size-fits-all approach.

Ravindra Jayaratne, Reader in Coastal Engineering, University of East London

This article is republished from The Conversation under a Creative Commons license. Read the original article.