Satellite detected water extents over Khongxedone District, Saravan Province & Sanasomboon District, Champasak Province, LAO PDR as of 1 October 2022

**UNOSAT code TC20220928LAO, GDACS Id: 1000922** This map illustrates satellite-detected surface waters in Sukhuma District, Champasak Province, Lao PDR as observed from a Sentinel-1 image acquired on 1 October 2022 at 05:45 local time. Within the extent of this map of 360 km2 , about 12 km2 of lands appear to be flooded. Based on Worldpop population data and the detected surface waters in the map extent, about 2,500 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 FL20230807LAO** This map illustrates cumulative satellite-detected surface waters over Khammouan & Savannakhet Provinces, Lao PDR as oberved from a Sentinel-1 image acquired on 04 August 2023 at 18:04 local time. Within the analysed area of about 25,000 km², a total of about 160 km² of lands appear to be flooded. Based on Worldpop population data and the detected surface waters in the analysed area, ~18,000 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 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 backscaterring properties of the radar signal.

**UNOSAT code: FL20190905LAO** This map illustrates satellite-detected surface water in Champasak province of Lao PDR as observed from Sentinel-1 imagery acquired on 10 September 2019. Within the analysed extent of about 14,400 km2, a total about 53 km2 of land appear to be flooded as of 10 September 2019. 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 Sentinel-1 imagery acquired on 10 September 2019 may seriously underestimate presence of standing flood water in built up areas due to backscattering of the radar signal

**UNOSAT code: TC20250722LAO, GDACS ID: 1001181** This map illustrates the satellite detected water extent in Bolikhamxai and Khammouan Provinces, Lao PDR as observed from Sentinel-1 satellite images acquired on 28 July 2025 at 05:50local time (22:50 UTC). Within the analyzed area of approximately 14,000 km², about 200 km² of land appears to be affected by floodwaters. Based on WorldPop population data and the flood extent, approximately 14,000 people are potentially exposed or living close to the 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 the backscattering properties of the radar signal

**UNOSAT code: FL20190905LAO** This map illustrates satellite-detected surface water in Khammouan and Savannakhet Province of Lao PDR as observed from Sentinel-1 imagery acquired on 11 September 2019. Within the analysed extent of about 8,300 km2, a total about 332 km2 of land appear to be flooded as of 11 September 2019. 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 Sentinel-1 imagery acquired on 11 September 2019 may seriously underestimate presence of standing flood water in built up areas due to backscattering of the radar signal

This map illustrates the satellite-detected water extent in the District of Khongxedone, Salavan Province, in the southwestern part of Lao People’s Democratic Republic after the tropical storm SONCA-17. The UNITAR-UNOSAT analysis used a Sentinel-1 satellite image acquired on the 30 July 2017 and detected several areas with potentially standing waters. In the district of Khongxedone ~2,921 ha are likely flooded mostly affecting the central part of the district along the “Xe Don” river. This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to UNITAR-UNOSAT.