Urbanization and flooding

Floods are one of the costliest natural disasters both in terms of damages and human livelihood losses. Urban encroachment on floodplains increases exposure and vulnerability to floods while population changes and climate change are expected to exacerbate those risks. Although the mechanisms of how urbanization affects flood risk are relatively well understood, there have been limited efforts in assessing the degree of floodplain encroachment globally and how it has changed both in space and time. With the advent of big-data geospatial processing tools, global-scale reconstructions of flood risk and changes in urban area have been made available and by combining these datasets, we can assess how floodplains have urbanized in relation to flood risk globally.