Slow movements of natural slopes are quite frequent in mountainous or hilly areas. They may display occasional crises, mostly related to the increase of pore water pressures induced by exceptional climatic conditions. A methodology consisting of combining the hydrogeological analysis and the geomechanical analysis is presented for the analysis of these phenomena. The evolution in space and time of pore water pressures obtained from hydrogeological modelling is used as input data for finite elements geomechanical modelling, in order to calculate stress variations and displacements. The proposed framework is applied to analyze a natural slope with three strategic infrastructure assets located at its toe. After being calibrated and validated, the model is applied to improve the understanding of the physical processes involved and to predict the landslide behaviour under different possible scenarios.