Flood impact analysis in Sylhet District, Sylhet Division, Bangladesh as of 26 June 2024

**UNOSAT code: FL20240502BGD, GDACS ID: 1102700** This map illustrates satellite-detected surface waters in Sunamganj Sadar and Bishwambarpur Upazilas, Sunamganj District, Sylhet Division, as observed from a Pleiades satellite image acquired on 26 June 2024 at 11:01 local time. Within the analysed area, about 120 km² of land appears to be flooded. Furthermore, within the analysed area, about 25,800 structures are identified as potentially affected by the floods (42% of the total structures in the analysed area), along with about 260 km of roads, as of 26 June 2024 This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to the United Nations Satellite Centre (UNOSAT).

**UNOSAT code: FL20240502BGD, GDACS ID: 1102700** This map illustrates satellite-detected surface waters in Chhatak Upazila, Sunamganj District, Sylhet division, as observed from a GLOBAL satellite image acquired on 26 June 2024 at 05:58 local time. Within the analysed area, about 20 km² of land appears to be flooded. Furthermore, within the analysed area, about 3,350 structures are identified as potentially affected by the floods (30% of the total structures in the analysed area), along with about 40 km of roads, as of 26 June 2024 This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to the United Nations Satellite Centre (UNOSAT).

**UNOSAT code: FL20220525BGD** This map illustrates satellite-detected surface waters and impact in Sylhet and Sunamganj Districts, Sylhet Division, Bangladesh as observed from a RCM-1 image acquired on 18 Jun 2022 at 17:54 local time. Within the analyzed area of about 1,325 km2, about 840 km2 of lands appear to be flooded. In this area, about 140 km of roads and 1 km of railway appear to be likely affected by the flood waters. Based on Worldpop population data and the detected surface waters, about 839,000 people are potentially exposed or living close to flooded areas. This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to United Nations Satellite Centre (UNOSAT). Important note: Flood analysis from radar images may underestimate the presence of standing waters in built-up areas and densely vegetated areas due to backscattering properties of the radar signal.

**UNOSAT code: FL20240502BGD, GDACS ID: 1001064** This map illustrates cumulative satellite-detected surface waters in Sylhet Division, Bangladesh as observed from Sentinel-1 images acquired on the 19th and 22nd June 2024 and using an automated analysis with machine learning method. Within the analysed area of about 12,000 km2, about 2,600 km2 of land appears to be flooded. Based on Worldpop population data and the detected surface waters in the analysed area, the potentially exposed population is mainly located in the district of Sylhet with ~1 million people, Habiganj with ~530,000 people, Sunamganj with ~420,000 people. This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to the United Nations Satellite Centre (UNOSAT). Important note: Flood analysis from radar images may underestimate the presence of standing waters in built-up areas and densely vegetated areas due to backscattering properties of the radar signal.

This map illustrates satellite-detected surface water extent in the northeastern part of Bangladesh using a Sentinel-1 satellite image acquired on the 15 June 2018. In the analysed area; about 500,000 ha of lands are likely affected. The population exposure analysis using WorldPop data shows that 3,500,000 people are potentially affected by floods in this analysed zone: ~1,500,000 are located in Sylhet Division and ~1,000,000 in Sumanganj Division and about 35% of the population is leaving within or close to inundated areas. This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to UNITAR-UNOSAT.

**UNOSAT code: FL20220525BGD** This map illustrates satellite-detected surface waters in Sylhet and Sunamganj Districts, Sylhet Division, Bangladesh as observed from a Chaohu-1 image acquired on 25 May 2022 at 22:23 local time. Within the analyzed area of about 730 km2, about 420 km2 of lands appear to be flooded. In this area, about 300 km2 of croplands and 70 km2 of herbaceous wetland appear to be likely affected by the flood waters. Based on Worldpop population data and the detected surface waters, about 307,000 people are potentially exposed or living close to flooded areas. This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to United Nations Satellite Centre (UNOSAT). Important note: Flood analysis from radar images may underestimate the presence of standing waters in built-up areas and densely vegetated areas due to backscattering properties of the radar signal.