ABSTRACT

Currently, more than half of the world’s population live in cities, especially in vulnerable coastal cities. It is estimated that many of the world’s large cities are vulnerable to rising sea levels and climate change, with millions of people being exposed to extreme floods and storms (Aerts et al, 2009). By the middle of this century, the majority of the world’s population will live in cities in or near deltas, estuaries or coastal zones, resulting in even more people living in highly exposed areas. Such socio-economic trends amplify the possible consequences of future floods, as more people move towards urban delta areas and capital is continuously invested in ports, industrial centres and financial districts in flood-prone areas. It is also expected that in many regions in the world, the frequency, intensity and duration of extreme precipitation events will increase as a result of climate change, as well as the frequency and duration of droughts. At the same time, many coastal cities suffer from severe land subsidence. As a consequence of these urban developments and projected land subsidence and climate change, the vulnerability of our coastal cities is expected to increase in the decades to come (Nicholls et al, 2008; Rosenzweig et al, 2010).