ABSTRACT
The capability of computer models to explain the hydrological changes observed in the landslides relies heavily on the appropriate definition of the boundary conditions and the landslide parameters. This chapter presents an example of how hydrological models, and in particular that of the Vallcebre landslide, may improve with the inclusion of terrain parameters and geometry features, that have been obtained by means of detailed geomorphological and hydrological field observations. Since July 1996, sixteen boreholes have been drilled in the landslide in order to log the geologic materials of the landslide; to provide undisturbed samples for laboratory tests; to allow in-situ hydrological testing; and to set up a monitoring network. The landslide of Vallcebre is large and active slide, located in the Eastern Pyrenees, 140 km North of Barcelona, Spain. The measured displacements show that the landslide has never stopped completely although velocities reduced drastically during dry periods.
