Modelling of groundwater flow through embankments for climate change impact assessment

J.M. van Esch (2012). Modelling of groundwater flow through embankments for climate change impact assessment. XIX International Conference on Water Resources
CMWR 2012,University of Illinois at Urbana-Champaign,June 17-22,2012

This paper assesses the consequences of droughts and periods of heavy precipitation for embankments. The proposed assessment procedure couples an agrometeorological model based on the Penmann-Monteith expression to a groundwater flow model based on Dupuit’s approximation. This approach is justified by the fact that the flow process through the unsaturated zone of an embankment is very complex due to highly varying meteorological conditions and soil heterogeneity and the available data can not support more advanced Richards calculations. Moreover, a comparison between both models for a peat dike application shows that the Dupuit model gives more robust results than a Richards model and is computationally more efficient. For this application extreme water table positions and related stability under wet and dry conditions are calculated and compared with measurements. Climate change will alter the boundary conditions and a tipping point analysis shows that the dike under consideration fails if the evapotranspiration increases by a factor two.