Author(s): Jorge P. Galve; Cristina Reyes-Carmona; Anna Barra; Rosa Maria Mateos; Oriol Monserrat; Jose Miguel Azanon; Jose Luis Perez-Garcia; Patricia Ruano; Davide Notti; Vicente Perez-Pena; Marta Bejar; Agustin Millares

Linked Author(s): Cristina Reyes-carmona, Agustín Millares

Keywords: Landslides; InSAR; UAV; Cloud computing; Geology

Abstract: The coast of Granada province (Spain) (also called "Costa Tropical") is a natural laboratory to study different types of slope movements because the region shows terrains very prone to landsliding. We have taken these slope movements as objects of study to test multi-technique approaches for characterizing and monitoring coastal landslides. In this coast there are several examples of severe pathologies associated with urban development on coastal landslides that offer a perfect setting to evaluate how landslides impact society. In this regard, landslides also hit the main infrastructures of this coastal region. Since 2014, we are applying different space- and ground- based radar interferometry (InSAR) techniques in combination with Uncrewed Aerial Vehicle Digital Photogrammetry (UAV-DP) and Terrestrial Laser Scanner (TLS) to study the kinematics and evolution of these landslides. Furthermore, we are performing detailed geological surveys to understand the cause of this slope movements usually associated with certain lithologies (i.e. phyllites or graphite mica schists) and structural settings (i.e. fault zones or dip slope situations). Here, we present several case studies where the mentioned techniques improved our capacity to evaluate the hazard of landslides impacting urban areas and infrastructures. In all cases the relationship between the geology of the site, InSAR/UAVDP/TLS data and the damage observed in human structures allowed a better understanding of the landslide kinematics and both the spatial and temporal evolution of the instability. In the "Marina del Este" resort, InSAR data was able to detect the movement of the landslide where the resort stand. A high rainfall period triggered an acceleration of the slope movement damaging several buildings of the resort. Now we monitor the current activity that continues to damage buildings. In the "Cármenes del Mar" resort we combined InSAR and UAV-DP measurements to estimate building displacements and geological surveys to determine the cause of the movement. Now, we are testing the GB-SAR technology on this site. Two other resorts are currently monitored using InSAR cloud computing techniques in order to correlate displacement gradients with building damages. UAV surveys were applied to study the evolution of a failure in a cut-slope of the main highway of the Costa Tropical. We use InSAR methods also to monitor a coastal road stretch and a tunnel hit by settlements associated with large slow-moving coastal landslides. These studies emphasise the need of integrating up-to-date technology with a deep knowledge of the terrain characteristics in order to improve hazard assessments and prevent losses associated with coastal landslides in populated areas.

DOI: https://doi.org/10.3850/IAHR-39WC2521711920221282

Year: 2022