Localization of deformation prone sites in the Himalayas using
multi-temporal InSAR and Sentinel-1 images
Abstract
Over the last two decades, the Himalayan region is affected by
deformation events such as landslides and land subsidence, spread over
different regions located within the Himalayas. The spatial distribution
of these events may well depend on the tectonics occurring beneath,
which requires understanding of long-term deformation over large areas.
Studies related to the identification of deformation zones has earlier
been carried out using conventional methods to identify deformation
zones. However, we need efficient methods to update these earlier
generated maps, which may require adding later events, which may also
belong to different class of events left unencountered earlier. In this
study, we make use of Sentinel-1 interferometric wide swath (IW)
datasets from the European Space Agency to localize deformation prone
sites in the Himalayan region. With over seven years of acquisition
(2014-2021) and large coverage (~270 km) of the dataset,
we attempt to monitor and understand the deformation activities
occurring in various parts of the Himalayas. This involves processing
gigantic stacks of interferograms generated from a large time series of
IW images, which may require devising better processing strategies. and
further analysis to generate a map showing sites affected by different
types of deformation events. This information can be used to identify
sites which require critical monitoring (using field surveys) and
rescue. The upcoming NISAR mission from NASA and ISRO is also focused
towards understanding deformation activities in the Himalayas, and the
proposed study may also benefit some of the studies planned for the
NISAR mission.