Major metropolitan areas around the world will become more vulnerable to floods and droughts due to the sheer extent of urban expansion – even in the absence of climate change, according to researchers from Texas A&M University.
Urban areas exposed to flood and droughts hazards are expected to more than triple by 2030 due to urban expansion alone. For instance, coastal megacities will house a majority of the urban population and become hubs of economic activity in the coming decades, says Burak Güneralp, lead author of the study.
While the largest increases in urban exposure to these hazards are expected in high-frequency flood zones and arid lands of Asia and Africa, cities in developed countries such as the U.S. will also become more vulnerable. For instance, the expansion in the metropolitan areas between Baltimore and New York will increase their exposure to flooding, while rapid growth in urban areas in central and southern California will increase their exposure to drought.
Climate change will simply aggravate the vulnerability of urban areas in the future, add the researchers, making proper planning critical to mitigate future losses due to floods and droughts. Steps taken could include cities preventing development in flood-prone zones to protect natural habitats, which in turn reduces the likelihood of being flooded, or adopting large-scale green infrastructure, such as reducing paved surfaces like roads and parking lots.