The natural hazards, like volcanic landslides and seismic activity, or induced by human activity (e.g. water extraction, mining,...), can have important effects in infrastructures and environment, producing great economic losses and threatening human lives. The occurrence of these phenomena are mostly related to areas that are susceptible to subsidence. Subsidence can result in permanent land loss, damage to infrastructure and buildings, and damage to the environment. Therefore, improving our understanding of the processes associated with hazards is crucial for developing systems that monitor, evaluate and predict hazards, and that aid decision makers during a crisis. Many of these hazards manifest themselves previously through deformations of the land and infrastructures. Synthetic Aperture Radar Interferometry (DInSAR) has been proved its unprecedented ability to detect millimetric displacements on the Earth surface over time scales of decades. An advanced interpretation tool Defsour, developed by the group in IGEO-CSIC, can model InSAR time series deformation data to constrain the location and geometry of the deformation sources as well as its temporal evolution. 3-D arbitrary sources for pressure and fractures/dislocations (strike-slip, dip-slip, and tensile) are adjusted. The Defsour software can automatically determine the number, nature, position, and 3D geometry of the causative source structures. In this presentation, the basic principles and case studies of the applications related to the deformation monitoring (InSAR) and deformation intepretation tool (Defsour) will be discussed and presented.