Satellite Detected Waters in Sylhet Division, Bangladesh

This map illustrates satellite-detected surface water extent in the central and northern parts of Bangladesh using a Sentinel-1 satellite image acquired on the 22 August 2017. The total analysed area is about 4,284,431 ha. In this analysed area; 1,099,369 ha (39%) of lands are likely affected. These lands are mainly cropland irrigated and rainfed areas and estimated to 1,039,350 ha. The population exposure analysis using WorldPop data shows that ~10,000,000 people are potentially affected by floods in the analysed zone: ~5,400,000 are located in Dhaka Division and ~2,750,000 in Rajshahi Division. Please note that for visualization purposes the analyzed area is wider than the extent of this map.This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to UNITAR-UNOSAT.

**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 central and southern parts of Bangladesh using a Sentinel-1 satellite image acquired on the 22 August 2017. In the analysed area; 608,747 ha of lands are likely affected. These lands are mainly cropland irrigated and rainfed areas and estimated to 475,000 ha. The population exposure analysis using WorldPop data shows that ~6,400,000 people are potentially affected by floods in the analysed zone: ~2,300,000 are located in Chittagong Division and ~2,170,000 in Dhaka Division. Please note that for visualization purposesanalyzed area is wider than the extent of this map. This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to UNITAR-UNOSAT.

**UNOSAT code: FL20200713BGD** This map illustrates satellite-detected surface waters over Chittagong, Dhaka, Mymensingh and Sylhet Divisions of Bangladesh as observed from a Sentinel-1 image acquired on 20 July 2020 due to the current monsoon rains. Within the analyzed area of about 14,250 km2, a total of about 7,120 km2 of lands appear to be flooded. Based on WorldPop population data and the detected surface waters, about 6,700,000 people area 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 UNITAR - 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 parts of Bangladesh (Sylhet distric) & India (Assam, Tipura and Mizoram states) using a Sentinel-1 satellite image acquired on the 15 June 2018. The analysis shows an increase of surface waters in Sylhet district (Bangladesh) and Assam state (India). This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to UNITAR-UNOSAT.

This map illustrates satellite-detected surface water extent in the northern part of Bangladesh using a TerraSAR-X satellite image acquired on the 16 August 2017. In the analysed area; 221,915 ha of lands are likely affected. The population exposure analysis using WorldPop data shows that 2,143,586 people are potentially affected by floods in this analysed zone: ~1,800,000 are located in Rangpur Division and ~280,000 in Dhaka Division. This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to UNITAR-UNOSAT.