The researchers analyzed data on flood risk and settlement patterns from 1985 to 2015 and found that urbanization is occurring faster in areas with high flood risk compared to less vulnerable areas. According to the report, in 2015, more than 11% of the world’s communities faced a high or very high risk of flooding, meaning these areas are susceptible to inundation of at least 50 cm (17 inches) deep during once-in-a-century floods.
The problem of building new cities in areas with increased vulnerability to flooding may be associated with a shortage of safe land for development. Often new buildings appear on flood-prone lands because safe areas have already been developed. Sometimes the decision to build in hazardous areas may be dictated by economic opportunities, such as in large port cities or tourist areas. However, the report recommends a focus on disaster preparedness, warning and evacuation systems in areas at high risk of flooding, and a review of land use plans and building codes in these areas.
