Where Rapid Urbanization Pushes Homes Into Floodways

Around the world, settlements in flood-prone areas have been expanding faster than the average of newly built cities, towns and villages, a paper released in early October in the scientific journal Nature has found. Despite climate change increasing the risk of floods, more people have begun living in these areas, driving up the likeliness of human and economic disaster.

The world region most affected is East Asia and the Pacific, where between 1985 and 2015, the share of settlements at risk of severe flooding increased from 7.8 percent to 9.5 percent. Around the world, just 5.2 percent of all human settlements carry the risk of being inundated by more than 1.5 meters of water in the case of a 100-year flood, which is an event that has the likeliness of 1 in 100 of occurring in any given year. This number was up from 4.3 percent in 1985.

Countries from the region that has been most likely to build in flood-prone areas even decades ago are numerous among the nations with the highest flood risk of settlements overall. Out of the eight low- and middle-income countries most at risk in 2015, Laos and Bangladesh have shares of extremely flood-prone settlements of upwards of 20 percent, while in Vietnam, this was upwards of 30 percent. China had the 7th highest risk of severe flooding of settlements in the report at 9.8 percent, up from 8.1 percent in 1985. While living close to bodies of water is sometimes associated with luxury, it is most often a sign of rapid urbanization and land scarcity in low- and middle-income countries. The authors of the study identify a lack of urban planning and disaster awareness in less developed regions as reasons why flood-prone areas are being settled in these nations when land becomes scarce. The pressure on rapidly growing cities which attract people looking for economic opportunity is causing this effect.