Satellite Detected Waters Extent in Vohipeni & Manakara Districts, Atsinanana Region, Madagascar

This map illustrates satellite-detected water extent as of 07 January 2018 over Mananjary district, Vatovavy-Fitovinany region, in Madagascar as detected by Sentinel-1. ~ 1000 ha of land over the communes of Tsiatosika and ~1300 ha in Ankatafana seem to be inundated. These zones are mainly agricultural and/or swamps. These waters are the results of recent heavy rains following the cyclone AVA-18 which made landfall the 05 January 2018. It is likely that flood waters have been systematically underestimated along highly vegetated areas along main river banks and within built-up urban areas, due to 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 satellite-detected water extent as of 07 January 2018 over Toamasina districts, Atsinanana Region, in Madagascar as detected by Sentinel-1. Some standing water areas could be observed north and south of Toamasina, mainly in the agricultural and/or open areas along the river. It is likely that floodwaters 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 satellite-detected water extent as of 09 January 2018 over Soaneriana Ivongo district, Analanjirofo region, in Madagascar as detected by Radarsat-2. Limited standing waters can be observed in the area. These zones are mainly agricultural and/or swamps. These waters are the results of recent heavy rains following the cyclone AVA-18 which made landfall the 05 January 2018. It is likely that flood waters have been systematically underestimated along highly vegetated areas along main river banks and within built-up urban areas, due to 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: TC20240102MDG, GDACS ID: 1001040** This map illustrates satellite-detected water extent in Vohipeno District, Vatovavy Fitovinany Region as observed from a Sentinel-1 image acquired on 05 January 2024 at 05:20 local time. Within the extent of this map of about 600 km², a total of about 50 km² of lands appear to be affected with flood waters. Based on Worldpop population data and the detected surface waters, about 17,700 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 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.

**UNOSAT code: TC20240102MDG, GDACS ID: 1001040** This map illustrates satellite-detected water extent in Manakara Atsimo District, Vatovavy Fitovinany Region as observed from a Sentinel-1 image acquired on 05 January 2024 at 05:20 local time. Within the extent of this map of about 300 km², a total of about 20 km² of lands appear to be affected with flood waters. Based on Worldpop population data and the detected surface waters, about 6,300 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 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.

**UNOSAT code: TC20220221MDG** This map illustrates satellite-detected surface waters in Manakara Atsimo district, Vatovavy Fitovinany region, Madagascar as observed from a Sentinel-2 image acquired on 24 February 2022 at 10:00 local time.  Within the analyzed cloud free zones of about 3,000 km2, a total of about 200 km2 of lands appear to be flooded. Based on Worldpop population data and the detected surface waters, about 39,000 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).