Giuseppe Centolanza

Mapping Vulnerable Urban Areas Affected by Slow-Moving Landslides Using Sentinel-1 InSAR Data

Landslides are widespread natural hazards that generate considerable damage and economic losses worldwide. Detecting terrain movements caused by these phenomena and characterizing affected urban areas is critical to reduce their impact. Here we present a fast and simple methodology to create maps of vulnerable buildings affected by slow-moving landslides, based on two parameters: (1) the deformation rate associated to each building, measured from Sentinel-1 SAR data, and (2) the building damage generated by the landslide movement and recorded during a field campaign. We apply this method to Arcos de la Frontera, a monumental town in South Spain affected by a slow-moving landslide that has caused severe damage to buildings, forcing the evacuation of some of them. Our results show that maximum deformation rates of 4 cm/year in the line-of-sight (LOS) of the satellite, affects La Verbena, a newly-developed area, and displacements are mostly horizontal, as expected for a planar-landslide. Our building damage assessment reveals that most of the building blocks in La Verbena present moderate to severe damages. According to our vulnerability scale, 93% of the building blocks analysed present high vulnerability and, thus, should be the focus of more in-depth local studies to evaluate the serviceability of buildings, prior to adopting the necessary mitigation measures to reduce or cope with the negative consequences of this landslide. This methodology can be applied to slow-moving landslides worldwide thanks to the global availability of Sentinel-1 SAR data.

Application of TerraSAR-X data to the monitoring of urban subsidence in the city of Murcia

This paper presents an analysis of the performance of TerraSAR-X for subsidence monitoring in urban areas. The city of Murcia has been selected as a test-site due to its high deformation rate and the set of extensometers deployed along the city that provide validation data. The obtained results have been compared with those ob-tained from ERS/ENVISAT data belonging to the same period and validated with the in-situ measurements.

Landslide monitoring with spotlight TerraSAR-X DATA

This paper aims to demonstrate that radar-based remote sensing techniques can be as effective as the conventional geotechnical ones for the detection and monitoring of well suited areas. Many of the high mountain landslides are vegetated areas that decorrelate faster at X-band. As in these scenarios the number of coherent scatterers is low and, in addition, the area of interest is usually small, the processing can be benefited of the usage of high-resolution data. This will maximize the chances of detecting persistent scatters coming from both natural targets and man-made structures. The high resolution Spotlight mode of TerraSAR-X is thus the perfect choice as it offers a fine resolution. On the other hand, its 11 days of revisit time and X-band carrier allows the monitoring of small variations in the landslide trend and deal with its variable dynamics.

Multi-temporal assessment of building damage on a landslide-affected area by interferometric data

Slow-moving landslides are widespread in different geological settings all over the world and they often are cause of significant damage to existing man-made structures. For such reason, a considerable interest towards innovative approaches useful to provide information on their evolution and on the interaction with existing buildings has grown among the scientific community and land management institutions. To this purpose, the combined use of C-band satellites and X-band Synthetic Aperture Radar sensors, has been successfully applied in several analyses aimed at the detection of spatial and temporal effects, in term of buildings damage induced by landslides. This work provides a general approach useful to investigate, at different levels of detail, the cause-effect relationship. The proposed methodology has been applied to the urban settlement of Moio della Civitella (Salerno province, Italy), whose whole territory is affected by several slow-moving landslides. C and X-band SAR data (acquired between 2002 and 2014), integrated with field survey of structural damage, enhanced an accurate examination of landslide effects on the urban texture of Moio della Civitella. The results allowed to generate empirical fragility curves for buildings on the study area. These curves can be used as a tool to forecast the future likelihood of the damage occurrence. Finally, the behavior of a masonry building aggregate has been assessed analyzing Differential Synthetic Aperture Radar Interferometry (DInSAR) time-series pre- and post-repair intervention, thus providing information also about the efficacy of restoration works.