Ground subsidence in Mekong delta, Vietnam (2018-10-26)

<br/> Activation date: 2018-10-26 <br/> Event type: Other <br/> <br/> Activation reason: <br/> The EMSN057 service provides geospatial information facilitating assessment of drivers of ground subsidence and to supporting analysis of the relation between detected ground subsidence and land use changes in Ca Mau, Long Xuyen and Rach Gia areas in the Mekong delta, Vietnam. The primary objective of the service is provision of spatially and temporally consistent, dense and synoptic results giving insight on the distribution and variance of subsidence phenomena in space and its dynamics in time. The persistent scatterers interferometry (PSI) technique, measuring ground deformations from stacks of archive SAR imagery (Sentinel-1 and TerraSAR-X), was utilized to estimate displacements. Products should complement ground based measurements, information from previous InSAR studies and contribute to evidence-based risk assessment.Annual Ground Subsidence Displacement&nbsp;The raster product, with 10 x 10m resolution, shows annual ground subsidence displacements in the vertical direction. The product was interpolated from displacement values of persistent scatterer points detected by the PSI technique from a stack of archived satellite SAR images.Annual Ground Subsidence Displacement ChangeThe change product shows differences of annual ground subsidence displacements in the vertical direction. It was obtained by deduction of previous from subsequent annual versions of Displacement products.In addition, average annual subsidence displacement velocity and displacement trend were evaluated from the PSI results, as demonstrated below.&nbsp; <br/> <br/>