Flood disasters like the one in Rhineland-Palatinate in July are becoming more frequent.
Photo: Thomas Frey / dpa
More and more people are affected by flood and flood disasters.
Because the number of disasters is growing - and because more and more people live in areas at risk of flooding.
This is shown by a new study published in the journal Nature.
For the survey, the scientists combined population data with satellite images; they evaluated a total of 12,719 images.
The result: Since the turn of the millennium, the proportion of people who experience floods has increased by almost a quarter - a trend that could intensify further by 2030.
Population growth increases where there is a threat
In concrete figures: between 2000 and 2018, at least 255 million people were directly affected by floods, possibly up to 290 million.
The analysis of the images also showed that the floods during that period extended over an area of 2.23 million square kilometers.
In the flood-prone areas, the population is growing faster than in a global comparison: While the world population increased by 18.6 percent in the study period, the increase in the danger areas was estimated to be more than 34 percent.
The researchers suspect that this development will continue to be particularly pronounced in several countries: For 57 countries - including North America, Central Asia and Central Africa - a significant increase in the proportion of the population exposed to flooding can be expected.
Sealed floors are a risk factor
Why is that?
In the study, the climate crisis is cited as one reason and the sealing of the soil as another.
If, for example, precipitation can no longer seep away, flood events become more likely.
In the same way, storms can lead to flood disasters, snowmelts or dam breaks.
And: Many cities and settlements are built on the water, on river banks and sea coasts.
The team around geographer Beth Tellman from Columbia University in New York illustrated the research results in a database, the "Global Flood Database".
It contains data on hundreds of flood disasters from the years 2000 to 2018.
The database should help scientists, but also crisis managers and insurance providers, it says on the website.
According to the study, floods can be expected to become more frequent.
Scientists are warning of more extreme weather events and storms in summer and autumn in Europe.
For future forecasts, the most accurate possible recording of flood risks could become more and more important.
vki / dpa