Book excerpt: The dangers that we face from geohazards appear to be getting worse, especially with the impact of increasing population and global climate change. This collection of papers illustrates how remote sensing technologies - measuring, mapping and monitoring the Earth's surface from aircraft or satellites - can help us to rapidly detect and better manage geohazards. The hazardous terrains examined include areas of landslides, flooding, erosion, contaminated land, shrink-swell clays, subsidence, seismic activity and volcanic landforms. Key aspects of remote sensing are introduced, making this a book that can easily be read by those who are unfamiliar with remote sensing. The featured remote sensing systems include aerial photography and photogrammetry, thermal scanning, hyperspectral sensors, airborne laser altimetry (LiDAR), radar interferometry and multispectral satellites (Landsat, ASTER). Related technologies and methodologies, such as the processing of Digital Elevation Models and data analysis using Geographical Information Systems, are also discussed.