Climate variability and global flood-risk: improving understanding, methods, and applications (2012-2016)

NWO VENI research project, Netherlands Organisation for Scientific Research
Project leader: Dr Philip Ward


The negative socioeconomic impacts of riverine flooding (e.g. economic damage, fatalities) are huge, as exemplified by recent floods in Pakistan, Thailand, and Australia. Over 95% of damage caused by flooding is due to inland floods.

Although flood impacts are felt at the local- to regional-scale, global-scale research is also vital: development agencies must know the potential magnitude and geographical distribution of consequences in order to estimate adaptation costs, and to prioritise management in worst-affected regions. Existing research focuses on the role of long-term climate change; the role of climate variability is less understood. Climate variability refers to natural temporal fluctuations around average climate, e.g. El Niño. In other sectors, research shows that variability is as important for policy and practice as long-term change. Past research by Ward et al. (2010) showed that El Niño significantly influences flood hazard worldwide.

This project addresses two knowledge-gaps: global-scale flood impacts; and the influence of climate variability on these. A risk-hazard framework will be used, whereby risk is the product of: hazard, exposure, and vulnerability.

Research aims

The main objective is to improve our understanding of the influence of climate variability on flood risk. The aims are to:

  • develop and validate a methodology to assess and map flood risk at the global-scale;
  • assess and map the influence of current climate variability on flood risk;
  • disentangle the relative influence of climate variability and long-term climate change on flood risk;
  • support the application of the scientific results in practice.

 Ward VENI 1

Difference (%) in median annual flood discharge between El Niño and neutral years (above) and La Niña and neutral years (below). Blue = wetter than in neutral years; red = drier than in neutral years.

Upcoming and recent events

10 April 2012      World Bank seminarGlobal Flood Impact Assessment by Philip Ward and Brenden Jongman, World Bank, Washington DC, USA.

13 April 2012      MIT Joint Program on the Science and Policy of Global Change research seminar by Philip Ward and Brenden Jongman. MIT, Cambridge, USA.

24 April 2012      EGU General Assembly presentationImpacts of ENSO on global hydrology by Philip Ward, Vienna, Austria.

More information

We are interested in sharing results and developing collaboration with interested research institutes and end-users. For more information, please contact Dr Philip Ward (

Related publications

  • Ward, P.J., Beets, W., Bouwer, L.M., Aerts, J.C.J.H. & Renssen, H. (2010). Sensitivity of river discharge to ENSO. Geophysical Research Letters, 37, L12402, doi:10.1029/2010GL043215.
  • Ward, P.J., Strzepek, K.M., Pauw, W.P., Brander, L.M., Hughes, G.A. & Aerts, J.C.J.H. (2010). Partial costs of global climate change adaptation for the supply of raw industrial and municipal water: a methodology and application. Environmental Research Letters, 5, 044011, doi:10.1088/1748-9326/5/4/044011