Analysis of satellite images: Flood disasters threaten more and more people

Flood disasters like in July in Rhineland-Palatinate 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 that are at risk of flooding.

This shows a new study, which was published in the journal “Nature”. For the survey, the scientists combined population data with satellite images, and overall they evaluated 12. 719 Pictures from. The result: since the turn of the millennium, the proportion of people who experience floods has increased by almost a quarter – a trend that extends to 2030 could further strengthen.

Where there is a threat, population growth increases In concrete numbers: Between 2000 and 2018 were at least 255 Millions of people directly affected by floods, possibly too up to 290 Millions.

The analysis of the images also showed that the floods in that period over an area of ​​2, 23 Wed llion square kilometers. In the flood-prone areas, the population is also growing faster than in the global comparison: While the world population in the study period increased by 18, 6 percent, the increase in the danger areas was estimated to be more than 34 percent.

at the end of July, a street in Calcutta in eastern India

Photo: Debarchan Chatterjee / ZUMA Wire imago images This development will continue in several countries, the researchers suspect and researchers: For 57 Countries – including North America, Central Asia and Central Africa – are expected to see a significant increase in the proportion of the population exposed to flooding.

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.

In July there were also floods in the USA, like here in the state of Michigan .

Photo: Emily Elconin / REUTERS The team around geographer Beth Tellman from Columbia University in New York illustrated the research results in a database, of the “Global Flood Database” . It contains data on hundreds of flood disasters from the years 2000 until 2018 fed in. 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 warn of more extreme weather events and Severe weather conditions in European summer and autumn . For future forecasts, the most accurate possible recording of flood risks could become increasingly important.