Subsidence activity maps derived from DInSAR data: Orihuela case study
- 1Geohazards InSAR laboratory and Modelling group, Infrastructures and services Department, Geological Survey of Spain, Rios Rosas 23, 28003 Madrid, Spain
- 2Geohazards InSAR laboratory and Modelling group, Geosciences Department, Geological Survey of Spain, Alenza 1, 28003 Madrid, Spain
- 3Unidad Asociada de investigación IGME-UA de movimientos del terreno mediante interferometría radar (UNIRAD), Universidad de Alicante, P.O. Box 99, 03080 Alicante, Spain
- 4Departamento de Ingeniería Civil, Escuela Politécnica Superior, Universidad de Alicante, P.O. Box 99, 03080 Alicante, Spain
- 5Department of Earth Sciences, Environment and Resources, Federico II University of Naples, Naples, Italy
Abstract. A new methodology is proposed to produce subsidence activity maps based on the geostatistical analysis of persistent scatterer interferometry (PSI) data. PSI displacement measurements are interpolated based on conditional Sequential Gaussian Simulation (SGS) to calculate multiple equiprobable realizations of subsidence. The result from this process is a series of interpolated subsidence values, with an estimation of the spatial variability and a confidence level on the interpolation. These maps complement the PSI displacement map, improving the identification of wide subsiding areas at a regional scale. At a local scale, they can be used to identify buildings susceptible to suffer subsidence related damages. In order to do so, it is necessary to calculate the maximum differential settlement and the maximum angular distortion for each building of the study area. Based on PSI-derived parameters those buildings in which the serviceability limit state has been exceeded, and where in situ forensic analysis should be made, can be automatically identified. This methodology has been tested in the city of Orihuela (SE Spain) for the study of historical buildings damaged during the last two decades by subsidence due to aquifer overexploitation. The qualitative evaluation of the results from the methodology carried out in buildings where damages have been reported shows a success rate of 100%.