Lava flows are a physical system in which the thermal, rheological and dynamical aspects are strongly coupled. The research employs both analytical and numerical models with the aim to highlight the relationships existing between the many quantities describing the system and to predict the evolution of a lava flow as a function of the effusion rate of lava at the eruption vent, of its rheological properties, of the ground morphology and of all the other variables controlling the flow. In particular, the research is aimed to understand the conditions and the mechanisms of formation of lava tubes, that have a strong impact on the cooling rate of the flow. The processes controlling the variation in time of the effusion rate of lava are also studied.