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.

Social learning, innovative adaptation and community resilience to disasters: the case of flash floods in Bangladesh

“…Experience and learning are two notable attributes of community resilience to flooding in Bangladesh (Haque and Zaman, 1993). Recent studies on flash flood experience in Bangladesh's wetlands have revealed increased vulnerability due to unprecedented magnitude of runoffs and river discharges, and a shift in timing of pre-monsoon and monsoon rainfall (Aldhshan et al, 2019;Kamal et al, 2018;Rahman et al, 2020). While numerous studies have confirmed that flood perceptions, social relationships, emotional attachment, living with floods and livelihood stresses are the key stepping-stones for adaptive learning and flood-related knowledge to foster resilience (Choudhury and Haque, 2016;Cook, 2010;Rahman et al, 2018), experiential learning alone would not suffice to deal with emerging flood risks.…”

“…Experience and learning are two notable attributes of community resilience to flooding in Bangladesh (Haque and Zaman, 1993). Recent studies on flash flood experience in Bangladesh's wetlands have revealed increased vulnerability due to unprecedented magnitude of runoffs and river discharges, and a shift in timing of pre-monsoon and monsoon rainfall (Aldhshan et al. , 2019; Kamal et al.…”

“…In 2017, local communities experienced both early flash floods and monsoon flash floods that caused catastrophic loss and damage to the main crops and other rural commodity production processes. These were attributed to the unprecedented heavy precipitations and a rapid runoff of water from the hilly areas (Aldhshan et al, 2019;FFWC, 2017). Kamal et al (2018, p. 478), analyzing the 2017 flash flood, found that while the middle-income households "are hesitant to take up any jobs and accept flood relief" and well-off households have higher recovering capacity, the poor are more vulnerable to floods than others, but they are also more adaptive (also see Choudhury and Haque, 2016).…”

“…In 2017, local communities experienced both early flash floods and monsoon flash floods that caused catastrophic loss and damage to the main crops and other rural commodity production processes. These were attributed to the unprecedented heavy precipitations and a rapid runoff of water from the hilly areas (Aldhshan et al. , 2019; FFWC, 2017).…”

ICT Uses, Constraints, and Challenges in Flash Flood Risk Management: A Case Study in North-Eastern Haor Areas of Bangladesh

“…To vividly depict a community's ICT utilization, it is necessary to understand the people's socio-economic characteristics, their location, ICT coverage, and their responses Flash floods occur in this area mainly due to heavy rainfall from the very steep uplands in the Meghalaya Hills [24]. The Meghalaya Hills on the Indian side of the border are among the world regions that receive the maximum annual rainfall (12,000 mm).…”