Résumé
In karstic media, groundwater surge flows can generate disastrous damages. In order to allow for the assessment and the prevention of water table rising risks, a methodology is developed. Firstly, the water table fluctuations at the millennial time scale are extrapolated and the rainfall events leading to these extreme groundwater surge flows are determined. Once the risk is diagnosed, a hydrodynamic model well suited for flow modelling in karstic and fractured reservoir is used. This model, based on the dual-porosity concept, allows drains and outlets of the karst system to be taken into account. The simulation yields the transient pressure distribution in the aquifer and the transient flow rate at the intersection between drains and conductive fractures, for a given rainfall recharge. This methodology has been tested and validated in a karstic Mediterranean basin in the framework of a new building construction.