Land deformation monitoring using optical remote sensing and PS-InSAR technique nearby Gangotri glacier in higher Himalayas

Abstract

In the present study, we have introduced a strategic technique for interrelating between slow land surface movement (SLSM) and land susceptibility (LS) map of a higher Himalayan region nearby Gangotri, India by integrating geospatial techniques based on modified frequency ratio technique acquired by optical remote sensing for LS mapping. On the other hand, PS-InSAR technique acquired by microwave remote sensing has been used for monitoring the SLSM. As SLSM is one of the major geological hazard susceptible for highly undulating terrain like Gangotri glacier basin in higher Himalaya which is also a most attractive tourist region in Uttarakhand, India. With the integration of this technology, it would be possible for monitoring SLSM and mapping LS of any hazardous area. PS-InSAR technique allows efficient planning by providing meticulous data about SLSM. PS-InSAR technique is used for monitoring SLSM in scale small within approximately millimetre range. Further, we have used SAR imageries of C band of ENVISAT satellite for the duration of March 2004–May 2007 for nearby Gangotri region. This work also comprises using satellite imageries of Landsat 7, Sentinel 2 and SRTM data for LS mapping purpose. The result shows that in the vicinity of the Gangotri region, the land surface movement was observed around 2 to 18 mm. Also, the study showed that the SLSM affected regions come under the High-risk zone of LS and vice versa.