Multitemporal Landslide Inventory and Activity Analysis by Means of Aerial Photogrammetry and LiDAR Techniques in an Area of Southern Spain

This paper deals with the use of aerial photogrammetry and LiDAR techniques to analyze landslide activity over a long time span—just 32 years. The data correspond several surveys (1984, 1996, 2001, 2005, 2009, 2010, 2011, 2013 2016) covering an area about 50 km2 along highway A-44, near Jaén (Southern Spain). An ad hoc combined photogrammetric survey 2010 was established as reference flight. flight processed by means direct orientation methods iterative adjustments between both sets. Meanwhile, historical flights available in public geographical servers were oriented transferring ground control points from Then, digital surface models (DSMs) orthophotographs generated, well corresponding differential (DoDs), which, after application filters taking into account estimated uncertainty ± 1 m, allowed us identify true changes on surface. analysis, complemented photointerpretation, led obtain multitemporal inventory study that analyzed order characterize type, morphology activity. Three basic typologies identified: rock falls–collapses, slides flows. These types present different morphometric properties (area, perimeter height interval) are associated conditions (height, slope, lithology). Moreover, set monitoring areas, common for flights, also used throughout period. Thus, some more active periods identified (2009–2010, 2010–2011, 2011–2013 1996–2001) among other less ones (1984–1996, 2001–2005, 2005–2009 2013–2016), which related rainy events dry years, respectively.