Insight to the potentials of sentinel-1 SAR data for embankment breach assessment

Abstract

Embankment breaching is one of the serious issues on the innumerous streams of the Brahmaputra floodplains during the monsoon season, which extends from May to October, leading to major agricultural damages by inundation and sand casting. These floodplains are highly fertile areas supporting a dense population largely dependent on agriculture for livelihood. Therefore, continuous monitoring and management is required so that the annual loss due to embankment breaching can be minimized. Traditional on-site methods are laborious and time consuming. The use of Synthetic Aperture Radar (SAR) data for this application is recommended instead of commonly used optical remote sensing data due to its all-weather capability and high sensitivity towards dielectric constant. This study analyses the potentials of C-band dual polarized (VV + VH) SAR data for embankment monitoring and breach assessment such as identification of breach locations, length of breach and area affected due to inundation after occurrence of breach. For the purpose of study, Solengi river, a north bank tributary of the Brahmaputra in Assam is used as a case study. Temporal Sentinel-1 data are continuously analyzed to monitor critical points of embankments and develop a suitable methodology to operationalize embankment breach monitoring. The initial analysis shows encouraging results. This methodology, if successful, may be helpful to automate the process of monitoring embankment breaches enabling better decision making.