Flood models in context. Bridging the gap between model experts and decision makers



Persons involved:

Anne Leskens (PhD-candidate)

Arjen Hoeksta (Promotor)

Marcela Brugnach (Supervisor)

Wytze Schuurmans (Supervisor)




Floods are major contributors to personal injury and to property damage and can strike with little warning. Problems related to floods have greatly increased over recent decades because of population growth and the subsequent development of extensive infrastructures in area’s vulnerable for floods. Increased frequency of extreme rainfall events, sea level rise and land subsidence potentially contribute to this problem as well. In flood management decisions are taken to deal with these flood risks, such as choosing protection measures as stronger levees, spatial planning that creates a flood resilient area or planning evacuations in emergency situations. A part of the information used to underpin these decisions is technical information provided by computer flood models, calculating water depths and flow velocities under different conditions such as dam breaches and storm surges.

Despite the advanced level of these computer flood models, their calculation results are limitedly used and sometimes incorrectly interpreted by decision makers. In literature different reasons have been mentioned for this limited use, such as that policy makers do not understand the outcomes, they do not accept uncertainties of outcomes or cannot deal with the restrictions in models. This situation is mainly derived from a poor understanding of the outcomes of computer models, on the side of policy makers, and a lack of understanding of the use of models in the decision making process, on the side of model developers. Both domains are loosely connected and, as a consequence, models are created from the point of view of technical possibilities, instead of from the perspective and requirements of decision makers. This mismatch is referred to in literature as the water information gap. In order to help bridging this water information gap, this research will investigate the requirements for computer flood models from the perspective of flood decision makers and match this with the possibilities and limitation of recent model techniques.

Theory about social networks and knowledge creation will be applied in case studies to understand the information needs of decision makers and to translate this to model requirements in three common contexts of flood decision making, namely designing protection measures, spatial planning and flood calamities. To examine the possibilities and limitations of models to meet the requirements of decision makers, new model technologies such as high spatial resolution and 3D visualization will be used to design pilot version of models to be evaluated in workshops. Finally, this research will result in a framework that gives modellers a better understanding which technical information decision makers require and in which format it should be communicated. Decision makers can use the framework in order to get better informed by which technical information is available to be helpful in their context and, subsequently, which information they can ask for by modellers.