Publication

Abstract : Efficient monitoring and prediction of floods and risk management for large reservoir is impossible without the use of Earth Observation data from space. One of the most important problems associated with flood monitoring is the difficulty to determine the extent of the flood area as even a dense network of observations cannot provide such information. The flood extent information is used for damage assessment and risk management. The use of optical imagery for flood monitoring is limited by the presence of clouds. In turn, Synthetic Aperture Radar (SAR) measurements from space are independent of daytime and weather conditions and can provide valuable information to monitor flood events. This is mainly due to the fact that smooth water surface provides no return to antenna in microwave spectrum and appears black in SAR imagery. The present study aims to analyze Sentinel-1A SAR data for its potential to map flood extent over the world’s Heritage site Kaziranga National Park, Natural Wonder of the World, Assam during the monsoon period of 2017. Level-1 Ground Range Detected (GRD) Sentinel-1 Cband (5.405 GHz) data collected in the Interferometric Wide Swath-(IW) mode were used to develop a procedure for reliable processing of the Sentinel-1 SAR images. Six SAR images have been collected during the period from 21st March 2017 to 26th July 2017. Those series SAR images were utilized to investigate the multi temporal backscatter properties. Based on the backscatter temporal variability, multi-temporal backscatter observations can be used to classify open water body and land.