Although great strides have been made in flood and drought risk mitigation, their impact on the world population is increasing. The effect is seen most clearly when a second climate disaster hits an already damaged area.
By analyzing 29 pairs of flood events and 15 droughts worldwide, the researchers set out to determine how risks were managed between the first and second events.
The scientists found that, in many cases, the risk factors did not improve. However, Barcelona and Central Europe stuck out as successful, even though these areas remain vulnerable.
“The improvements in Barcelona’s rainwater network over the last twenty years have been decisive in alleviating the effects of floods in the city. In fact, while in the Metropolitan Area of Barcelona there has been a slight increase in flooding since 1981, this trend is negative in Barcelona. However, this is not enough,” said study co-author Professor María del Carmen Llasat.
Flood mitigation actions in Germany and Austria were also considered successful. Barcelona, Germany, and Austria have a couple things in common: an investment in infrastructure such as dykes and stormwater reservoirs, and better government engagement, including warning systems.
However, even these mitigation measures come with risks. Professor Llasat explained: “Large investments such as those made in the city of Barcelona or in Central Europe are not possible for everyone. In fact, they would not be desirable either. Recent studies have shown that they can lead to a false sense of security (especially in the case of river flooding), as they increase the occupation of flood zones and thus the associated risk.”
The experts believe the way to true success is community-based flood mitigation that involves nature-based solutions.
“It is necessary for the administration to improve its knowledge of risk, the distribution of the most flood-prone areas in the city, how to act when there are heavy rains, etc.,” said Professor Llasat.
“Regarding the citizens, it is necessary to become aware that this risk will increase with climate change and that we will need citizen participation. Education in schools, compulsory information on flood risks, improved warnings to the population and guidelines on how to act both preventively and during the emergency are also some of the points that should be considered to reduce the impact of these natural events.”
The research is published in the journal Nature.