Safety of dikes and embankments in the Netherlands with special reference to earthquakes

Abstract

The protection against flooding is an important topic in the Netherlands. Based on statutorily defined sea and river levels which have to be withstood, safety is expressed as an acceptable annual probability of flooding for each area protected by water-retaining structures. This hazard assessment considers primarily the basic threat of extreme high water levels alone or in combination with (specific) storm conditions. However, combinations of high water levels with unrelated damaging events may also contribute to the total flooding hazard. This paper describes the general approach for the assessment of the possible combined failure mechanism leading to the scenario 'flooding due to earthquake-induced damage'. Based on the results of simplified slope stability calculations, the conclusion is drawn that the contribution of this scenario to the total probability of flooding is exceedingly small for the lower river region of the Netherlands.