Satellite Detected Surface Waters Extent in Ho Chi Minh City Area, Vietnam

This map illustrates the satellite-detected surface waters extent in Long An province and in the southern part of Cambodia, as observed from the Sentinel-1 SAR images acquired on 16 & 28 August 2018. In the analysed area, an increase of surface waters is observed mainly in agricultural and paddy fields areas. In addition, using WorldPop data, we can estimate that ~200,000 people are living within or close to flooded zones in the province of Long An. It is likely that flood waters have been systematically underestimated along highly vegetated areas along main river banks and within built-up urban areas because of the special characteristics of the satellite data used. This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to UNITAR - UNOSAT.

This map illustrates the satellite-detected surface waters extent in southern part of Vietnam, as observed from the Sentinel-1 images acquired on 07 November 2017, following the landfall of tropical cyclone DAMREY-17 ON 05 November 2017. In the analyzed area, 700,000 ha of lands, mainly agricultural and paddy fields are likely flooded. This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to UNITAR - UNOSAT.

This map illustrates the satellite-detected surface waters extent in the southern provinces of kien Giang, An Giang, Dong Thap & Can tho as observed from the Sentinel-1 SAR images acquired on 16 & 28 August 2018. In the analysed area, an increase of surface waters is observed mainly in agricultural and paddy fields areas. It is likely that flood waters have been systematically underestimated along highly vegetated areas along main river banks and within built-up urban areas because of the special characteristics of the satellite data used. This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to UNITAR - UNOSAT.

**UNOSAT code: TC20201013VNM** This map illustrates satellite-detected surface waters in Ha Tinh and Nghe An Provinces of Viet Nam as observed from a Sentinel-1 image acquired on 18 October 2020. Within the analyzed area of about 9,000 km2, a total of about 500km2 of lands appear to be flooded. In Ha Tinh province, the water extent appears to have increased of about 300 km2 since 15 October 2020. Based on Worldpop population data and the detected surface waters, about 220,000 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 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 the satellite-detected surface waters in Binh DinhNam Province, Vietnam, as observed from the Sentinel-1 image acquired on 10 November 2017, following the landfall of tropical cyclone DAMREY-17 on 05 November 2017. The districts located in the coastal areas have been affected by the floods; especially the ones located in the southern coastal part of the province and more particularly Phu Cat, An Nhon, Tuy Phuoc and Qui Nhon districts. Around 17,000 ha of lands were identified as flooded within the province of Bihn Dihn. It represents an increase of ~140 % of the surface waters in the analyzed zone. In this analyzed area and according to the WorldPop data, more than 100,000 people are potentially exposed to flood waters. This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to UNITAR-UNOSAT.

This map illustrates the satellite-detected surface waters in Quang Nam Province, Vietnam, as observed from the Radarsat-2 image acquired on 07 November 2017, following the landfall of tropical cyclone DAMREY-17 on 05 November 2017. The districts located in the coastal areas have been affected by the floods; especially the ones located in the northern coastal part of the province and more particularly Dien Ban, Duy Xuyen and Thang Binh districts. Even if the province of Quang Nam was not in the passage of the cyclone, ~ 35,000 ha were identified as flooded within the analyzed area (8,700 km2). It represents an increase of about 230% of the surface waters in the analyzed zone. This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to UNITAR-UNOSAT.