Development of a landslide inventory for a region in Mexico using Very High Resoution Satellite Stereo-Images

In recent years, the analysis of stereo-pairs of Very High Resolution (VHR) satellite images has represented a valid alternative to aerial photographs for landslide recognition and mapping. The availability of images wiTheven higher spatial resolution and improved digital visualization and analysis techniques have encouraged investigators to use satellite images to detect and map recent and old landslide features. In this paper we present the results of a landslide geomorphological inventory prepared for the municipality of Pahuatlan, Mexico, based on stereoscopic interpretation of GeoEye 1 VHR images. A 54 km2 study area was defined for landslide recognition. In the study area, elevations range from 450 m to 1,500 m above sea level. The study area has a mountainous terrain with deep ravines and high summits derived from orogenesis of the Sierra Madre. Mesozoic rocks, including conglomerates, shale, siltstones and limestone, outcrop in the area. The climate is temperate, with abundant precipitation all year and a mean annual rainfall of 2,500 mm. Vegetation types are rain and coniferous forest, with a high level of deforested areas also present. According to the landslide inventory, in Pahuatlan municipality, there are 385 recent landslides, 171 old landslides and 21 very old landslides. The total landslide density is 10.5 landslides per km2. The area most affected by landslides was concentrated in 34 km2 and it was measured using Double Pareto analysis. In addition, stereo-images were used to generate a very high resolution Digital Elevation Model (10 m spatial resolution). VHR satellite images are efficient for landslide identification; they reduce the time to acquire information and allow a continuous stereo-model view without changing the set of images, although the associated costs are quite high. © Springer International Publishing Switzerland 2014.