Be careful, risk of flooding! These cities are the most affected

Climate change has many faces: Firstly, there is the almost unbearable heat in summer, which becomes noticeable in spring or even in winter with above-average temperatures and little snow.

In Asia and the USA, however, hurricanes make their rounds more frequently. They are accompanied by heavy rains, which quickly flood entire towns and cities and transform small bodies of water and streams into raging rivers. The images of Hurricane Kathrina in 2005 in the southeast of the USA or – from the more recent past – the muddy devastation in the Ahr Valley (July 2021), in Austria and Slovenia (August 2023) or parts of China (September 2023) remain memorable to this day.

Where will people particularly need to prepare themselves against such extreme events in the future? In Europe, less so, scientists commissioned by the Organization for Economic Co-operation and Development (OECD) have found. Coastal cities in the Asia-Pacific region are particularly affected.

Cities in developing countries are particularly affected by floods

For the first report of this kind, the researchers examined 136 port cities worldwide with at least one million inhabitants and sorted them according to the amount of damage to the population and assets (real estate, infrastructure, buildings). Around 40 million people are already affected by floods at least once in 100 years. According to the report, this corresponds to approximately 0.6 percent of the world’s population.

Relative to population, these cities suffer the most damage from floods and floods:

The study authors estimate that the number of people affected could at least triple by 2070. What is striking is that, with two exceptions, most of the high-risk cities are in poorer and developing countries. The reasons for this include, among other things, the education level of the population and the financial situation of the countries, because without money and knowledge about climate change, it is more difficult to implement adaptation and protection measures. Cities and entire countries are becoming more vulnerable to the consequences of climate change.

However, if the statisticians only take assets into account in their calculations, more cities from industrialized countries rank in the top ten:

In their report, the authors emphasize that a high risk of flooding does not necessarily mean devastating impacts. These in turn depend heavily on the protection and adaptation measures that a city takes. “At a global level, however, it is expected that economic growth will enable an overall improvement in the level of protection in coastal cities around the world,” the scientists write. However, protective measures cannot prevent floods and floods, they can only mitigate the consequences.

More people are moving to risk areas

This is also urgently needed because, as another study from the specialist magazine “Nature” shows, more and more people around the world are moving to potential flood areas. Between 1985 and 2015 the proportion increased by 122 percent. Countries such as the Netherlands, Vietnam, Laos, Bangladesh, Japan, Egypt and China most often build in flood risk areas. “Instead of adapting to climatic threats, many countries are actively increasing their risk,” the study authors summarize their results.

The fact that people voluntarily move to risk areas is due to the economic power that develops in cities. These in turn are usually located on rivers or seas. If people move to cities, the necessary living space must be created. “As the city expands, it is likely that it will move into areas that were previously avoided, such as flood areas,” a co-author of the study told Euronews. Climate change is not always to blame when regions are flooded.

Sources: Climate Adapt, World Bank, Euronews, OECD, Georgetown Climate Center, Miami Government, Resilient Kolkata, Osaka government,