Assessment of cyclone induced flood using microwave Synthetic Aperture Radar (SAR) data in four blocks of East Midnapore district, India

Abstract

East Midnapore district is one of the flood prone regions of West Bengal, India. Geomorphological character, topographic nature and geographical location are the main causes of such kind of flood extensiveness in this region. Four most flood prone blocks of East Midnapore district are considered in this study to analyse, monitor and estimate the flood consequences. Flood intensity, duration of water logging, frequency, interval of flood and measurement of the vulnerability are the important parameters to assess the flood risk. Synthetic Aperture Radar (SAR) data has its distinct character to collect the data at the flood time even in bad weather and it can also penetrate the cloud cover and can avoid weather caused signal attenuation. European Space Agency’s (ESA) Sentinel-1 SAR before and after flood data (2021) of Vertical transmit and Vertical receives (VV) polarization has been used to monitor and detect the flood extension and assess the inundated areas. The decibel (dB) value is mentioned and speckle noise correction is applied before and after both images. By applying the threshold dB values on both images, the flood inundated areas are detected and extracted from the natural water bodies. A village wise water logged condition of this region was observed for a long time and the study reveals that total 11612.28 ha. areas are submerged due to flood inundation. For the development of the agriculture and aquaculture in terms of the local economy a special care should be taken in this low land flood, affected region.