Mountain areas are highly dynamic and sensitive regions. Changes in human land use and climate conditions, an increasing number of natural hazard phenomena, and increased competition in a globalised economy are putting the environment and societies in mountain regions under pressure. Consequently, the observation of these phenomena or their representative indicators at various scales in time and space has become an urgent task. Monitoring — ie the repetition of such observation activities — in sufficient frequency for large and remote areas is only economically feasible when supported by remote sensing techniques. Some products based on Earth Observation (EO) data have been developed successfully and have become standard applications over the last decade, an example being land use mapping. However, a large number of potential remote sensing based tools are still “work in progress,” eg those aiming to take advantage of the latest available techniques such as very high resolution optical satellite images, radar, or laser sensors. This is particularly true for mountain regions, where steep terrain complicates image processing, whilst the heterogeneous landscapes demand products in fine resolution and of high spatial accuracy at the same time.
