Floodrisk assesment Mastenbroek

Within the framework of the ‘National Flood Risk Assessment Project’ all dike rings in The Netherlands are investigated and evaluated with regard to the probability and effects of flooding. The Ministry of Transport, Public Works and Water Management developed a new method to assess the safety against flooding. One of the dike rings evaluated by Lievense is the dike ring #10 at Mastenbroek along the IJssel river delta.

For each dike section the following failure mechanisms are analysed: damage of revetments and erosion, overflow and wave overtopping, bursting and piping, and land sliding (geotechnical stability). Nine structures (sluices, locks and pumping-stations) were reviewed for retaining water level, probability of failure of closing gates, and structural strength and stability in order to assess the overall failure probability. Together with the assessment of potential damages in case of flooding the flooding risk (risk = probability x effect) is determined.

Activities:

• review of field data
• assessment of failure probability of 48 dike sections and 9 hydraulic structures
• analysis of failure mechanisms
• computation of flooding probabilities
• prediction of damages and casualties
• determination of integrated flood risks