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Paper title EXPLORING LAND SUBSIDENCE WITH A-DINSAR THEMATIC APPS OF THE GEOHAZARDS PLATFORM
Authors
  1. Guadalupe Bru Centro Nacional Instituto Geológico y Minero de España, IGME-CSIC (CODE 030611) Speaker
  2. Pablo Ezquerro
  3. Carolina Guardiola-Albert Instituto Geológico y Minero de España IGME
  4. Marta Béjar-Pizarro Gelogical Survey of Spain (IGME-CSIC)
  5. Gerardo Herrera European Commission
  6. Roberto Tomás Jover Universidad de Alicante
  7. María Navarro-Hernández Universidad de Alicante
  8. Juan M. Lopez-Sanchez University of Alicante
  9. Ali Hakan Ören
  10. Barış Çaylak
  11. Alper Elçi Dokuz Eylül University
  12. Khaldoun Shatanawi
  13. Alsharifa Hind Mohammad
  14. Husam A Abu Hajar
  15. Roberta Boni
  16. Michelle Rygus University of Pavia
  17. Laura Pedretti University of Pavia - Department of Earth and Environmental SCiences
  18. Claudia Meisina University of Pavia
  19. Yuetin Li
  20. Claudia Zoccarato University of Padova
  21. Pietro Teatini Università di Padova
Form of presentation Poster
Topics
  • A7. Hydrology and Water Cycle
    • A7.05 InSAR for the groundwater management
Abstract text Land subsidence is a geological hazard characterized by the gradual downward movement of the ground surface. It can be induced by natural processes (e.g. tectonic, diagenesis) or human activities (e.g. subsurface fluid extraction). Extensive groundwater withdrawal from aquifer systems is the main factor causing land subsidence in areas where surficial water is scarce. Groundwater pumping causes a pressure decline in the sandy units and in adjacent unconsolidated deposits (aquitards). As a result, the stress exerted by the load of the overlying deposits is transferred to the grain-to-grain contacts increasing the effective intergranular stress. Depending on the compressibility of the soil, the depleted layers (aquifers and intervening aquitards) compact, thus causing land subsidence. Among other risks, compaction permanently reduces the capacity of the aquifer-system to store water. Therefore, assessing land subsidence is a key step to understand and model aquifer deformation and groundwater flow, which can help to design sustainable groundwater management strategies.
Advanced Differential Interferometry Synthetic Aperture Radar (A-DInSAR) is a satellite remote sensing technique widely used to monitor land subsidence. The Sentinel-1 mission, from the Copernicus European Union's Earth Observation Programme, comprises a constellation of two polar-orbiting SAR satellites that provide enhanced revisit frequency and worldwide coverage under a free, full, and open data policy. To handle and process huge and constantly increasing Sentinel-1 archive, the Geohazard Platform (GEP) on-demand web tool initiative was launched in 2015. In this online processing service, SAR images and A-DInSAR algorithms are located together in a friendly interface. The processing chains run automatically in the server with very little user interaction.
The GEP service is particularly useful for preliminary a land subsidence analysis, as all the data and technical resources are external and in addition the processing time is relatively fast. We tested different A-DInSAR algorithms (named Thematic Applications) included in the GEP to explore land subsidence in four water stressed aquifers around the Mediterranean basin. Located in Spain, Italy, Turkey and Jordan, they are characterized by largely different hydrogeologic features. These pilot sites are studied within the framework of the RESERVOIR project that aims to provide new products and services for a sustainable groundwater management model. This project is funded by the PRIMA programme supported by the European Union. The preliminary land subsidence results provided line-of-sight LOS velocity maps obtained from the GEP and allowed us to identify potential deformation over wide areas before carrying out more refined and conclusive A-DInSAR analyses.