On safe ground? Analysis of European urban geohazards using satellite radar interferometry

Abstract

Urban geological hazards involving ground instability can be costly, dangerous, and affect many people, yet there is little information about the extent or distribution of geohazards within Europe's urban areas. A reason for this is the impracticality of measuring ground instability associated with the many geohazard processes that are often hidden beneath buildings and are imperceptible to conventional geological survey detection techniques. Satellite radar interferometry, or InSAR, offers a remote sensing technique to map mm-scale ground deformation over wide areas given an archive of suitable multi-temporal data. The EC FP7 Space project named PanGeo (2011-2014), used InSAR to map areas of unstable ground in 52 of Europe's cities, representing ~15% of the EU population. In partnership with Europe's national geological surveys, the PanGeo project developed a standardised geohazard-mapping methodology and recorded 1286 instances of 19 types of geohazard covering 18,000 km 2. Presented here is an analysis of the results of the PanGeo-project output data, which provides insights into the distribution of European urban geohazards, their frequency and probability of occurrence. Merging PanGeo data with Eurostat's GeoStat data provides a systematic estimate of population exposures. Satellite radar interferometry is shown to be as a valuable tool for the systematic detection and mapping of urban geohazard phenomena.

Identifying natural and anthropogenically-induced geohazards from satellite ground motion and geospatial data: Stoke-on-Trent, UK

“…The geohazards are defined as single-part polygons, with the exception of the 167 landslides identified which, in accordance with the PanGeo project methodology, were grouped into 1 multi-part polygon. Comparison of these results with the 51 other PanGeo cities, ranks Stoke-on-Trent 28 th for percentage of the city affected by geohazards, 19 th for number of geohazard types present and 23 rd for population exposed to geohazards (Capes & Teeuw, 2017). The dominant geohazard (in terms of area covered) is ground movement caused by postmining groundwater recharge and mining-related subsidence (93.2 % of total geohazard area).…”

“…Areas affected by deep ground motions, natural ground instability, natural ground movement and man-made (anthropogenically-induced) ground instability were identified. A total of approximately 10 000 km 2 across the 52 cities was affected, equating to 20% of the total area examined and exposing nearly 32.5 million people (Capes & Teeuw, 2017). Stoke-on-Trent (Jordan et al, 2013) and London (Cigna et al, 2014) were selected as targets for the UK and the British Geological Survey (BGS) led the investigation of these areas.…”

Automatic Parametrization of Urban Areas Using ALS Data: The Case Study of Santiago de Compostela

“…On one side, satellite imagery has been used for a large number of applications. Some examples are the analysis of urban hazards [9,10], the segmentation of urban features [11,12], or shadow detection [13], among others. On the other side, laser scanner technology has been used in multiple research fields during the last decade, and it is proven to be a useful tool for a wide number of applications that may have an impact on the evolution of the sustainability and resilience of the cities.…”

A-DInSAR Monitoring of Landslide and Subsidence Activity: A Case of Urban Damage in Arcos de la Frontera, Spain

“…If the compaction is spatially uneven, the structures at the surface will undergo differential settlement. The high spatial density of measure points provided by DInSAR allows the study of urban damage caused simultaneously by ground surface displacements related to different natural processes [20,21].…”