A team of researchers from the University of Hawaiʻi at Mānoa and Louisiana State University have conducted a national, county-based assessment of population trends in urban areas located in high-risk flood zones. The findings, published in Annals of the American Association of Geographers, note strong spatio-temporal variations of urban development in flood zones.
The team, led by Yi Qiang, an assistant professor of Geography, studied development trends from 2001 to 2011 across the continental U.S. Analyzing the U.S. Federal Emergency Management Agency’s 100-year flood maps, land cover data and census data, they found that coastal communities are generally more responsive to flood hazards by avoiding urban development in flood zones than inland communities.
Population exposure to flood hazards can be a result of lack of awareness of potential hazard (awareness), being able to cope with and adapt to the adverse impacts (coping and adaptive capacity), a trade-off decision between flood risk and amenities in flood zones (trade-off), and governmental and instructional factors. The lack of responsiveness to flood hazards is an alarming signal for inland communities that could suffer from more losses than coastal communities when flooding events of the same severity strike.
Researchers, however, also noted the flood exposure is dynamically changing over time. Despite most coastal communities have a decrease in urban development in flood zones, several exceptions are noticeable. The most significant were in New York City and Miami, where more development in flood zones were identified during 2001-2010. In these exceptions, Qiang notes that further investigations and better policy to reduce flood risks are critical.
