Hydrological variability, transboundary floods and institutional capacity: are we prepared for tomorrow’s problems?

Floods are among the world’s most frequent and damaging types of disasters and annually affect the lives of millions all over the globe. Over time, human exposure and vulnerability to floods has increased with a growing and increasingly urbanized population. The projected effects of climate change on hydrology, aggravated by a range of social, economic and political processes will continue to increase this vulnerability. Nonetheless, vulnerability of societies and their institutions to floods remains poorly understood. Using global data, this paper examines the nexus of transboundary flood events and social vulnerability: which international river basins have experienced transboundary floods, i.e. floods that affect two or more countries, in the past, and which are forecast to experience increased hydrological variability in the future, but lack institutional provisions, i.e. river basin organizations and/or treaties, to deal with these shared events?