Land subsidence is the shifting and sinking of the ground, and it can be disastrous for low lying countries. Subsidence can be caused by several factors, including erosion, earthquakes, mining, and even rapid urbanization.
Because of the risks that subsidence poses to urban areas and agriculture, it is crucial to find ways to monitor and map subsidence in regions where city infrastructure, buildings, homes, and crop yields are under threat.
Many regions in Italy are impacted by subsidence, which makes the country a prime region to test monitoring and mapping techniques.
Currently, groundwater monitoring and optical leveling are used to map subsidence, but tracking land shifts over the long term requires a more comprehensive approach.
This is why researchers from the University of Florence compiled radar data from the European Space Agency’s Copernicus Sentinel-1 mission to create over ground deformation maps for Tuscany showing surface sinking over time.
Satellite radar imaging is one of the most accurate ways to subsidence and damage.
“Satellite data, acquired with short revisiting times and promptly processed, can contribute to the detection of changes in ground deformation patterns, and can feed a decision support system for hydrogeological risk mitigation strategies,” said Professor Nicola Casagli from the University of Florence.
Having a detailed record of subsistence can help researchers focus on unstable areas not immediately identifiable by ground monitoring techniques.
“Thanks to Copernicus Sentinel-1, the SAR industry paradigm has definitely changed from ‘mapping’ to ‘monitoring.’ Tuscany is the first region in Italy to benefit from this,” said Alessandro Ferretti, the CEO of TRE ALTAMIRA, which works with satellite data to provide mapping solutions.
Image Credit: Copernicus Sentinel data (2014-19), processed by ESA/TRE ALTAMIRA