Multifunctional use of flood defences

Research challenges

Flood defences have the potential to be integrated with many other function (e.g. nature, recreation, transport, housing etc.). Adding some functions can increase the risk of flooding of a primary flood defence whereas other functions (e.g. natural foreshores) can provide synergies to decrease flood risk. The objective is to gain more insight in the effects of the multifunctional use of flood defences on flood risk using the new probabilistic risk standards recently adopted in the Netherlands.

Methods

• Defining limit states for additional functions on dikes
• Calculating how multifunctional dike elements affect the probability of failure
• Calculating the probability a multifunctional dike cannot fulfil its secondary functions
• Apply these insights to case studies of multifunctional dikes in the north of the Netherlands

Results and conclusions

The means to objectively compare new dike concepts is lacking within the new risk standards. As a result, innovative multifunctional options are only occasionally implemented. This research will bridge this gap to allow for implementation of suitable multifunctional dike concepts by contributing to a comparative framework for multifunctional dikes.