Bangladesh - Satellite Detected Water Extent in Cox's Bazar District, Chittagong Division

This map illustrates the satellite-detected water extent in the District of Chittagong, Chittagong Division, in the southeastern part of Bangladesh after the tropical cyclone Mora-17. The UNITAR-UNOSAT analysis used a Sentinel-1 satellite image acquired on the 30 May 2017 and detected several areas with standing waters. In the district of Chittagong ~4,790 ha are likely flooded and almost 12 km of the local roads seem to be affected. The population exposure analysis using WorldPop data shows that ~70,000 people are potentially affected by floods within map extent. 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 around Maheshkhali, Chakaria and Cox'S Bazar Sadar Upazilas in the District of Cox's Bazar, Chittagong Division in the south eastern part of Bangladesh as detected by a TerraSAR-X image acquired on the 1st June 2017. A total of ~20,000 ha of lands seem to be affected with flood waters. Some of the affected lands are mainly agricultural fields. The analysis of this satellite image reveals also that about 100 km of roads with mainly tertiary roads seem to be also potentially affected. We can also estimate, within this map extent and using the WorldPop data, about 265,000 people living in flood affected zones. 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 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 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.

This map illustrates satellite-detected surface water extent in the central part of Bangladesh using a Sentinel-1 satellite image acquired on the 12 August 2017 with a total surface of 4,280,650 ha. In this analyzed area; 1,644,983 ha (38%) of lands are likely affected. These lands are are mainly cropland irrigated and rainfed areas and estimated to 1,576,351 ha. The population exposure analysis using WorldPop data shows that ~17,000,000 people are potentially affected by floods in the analysed zone: ~8,400,000 are located in Dhaka Division and ~5,750,000 in Rajshahi Division. This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to UNITAR-UNOSAT.