Flash flood area mapping using sentinel-1 SAR data: a case study of eight upazilas in Sunamganj district, Bangladesh

Abstract

Extraction of information from Remote sensing satellites is significant and effective tools for hazard activities such as flooding. essentially, if the field was under disaster conditions it will be so difficult to do surveying in that region. flash floods are sudden natural disaster events, which impact an extensive variety of ecological elements and applications associated with natural resources, agriculture, human activities and natural phenomena and economies. The utilization of SAR information gives much more information to control and monitor the flash floods, and additionally the information used for the damage assessment after the disasters. To recognize the region that has been flooded; a few procedures were trailed by Snap and Arc Map software. The fundamental step was flooded area in image its determined during extraction process by sets threshold estimation of radar backscatter which is taken from the calculation binary algorithm (the equitation of band math) to decide if a specified raster pixel is overflowed or not. The outcomes are indicated extend out of flash floods amid to time. On 26th of Mar Flood area was about 4.5%, however, it became around 45% in about month from the disaster beginning. This is evidence of the speed of the flood on the grounds that the nearness of high statures with Heavy rains around there and its foundation, on first of May agriculture damages, was around 1037 km2 as result appeared of this flash flood. Therefore, these outcomes are extremely helpful to make an evaluation of situations to save the people lives, property and nature from this natural disaster in the future.