Satellite detected water extents over Chaiyaphum and Nakhon Ratchasima Provinces, Thailand as of 4 October 2022

**UNOSAT code: FL20240912THA** This map illustrates cumulative satellite-detected water extent from multiple satellites in Chiang Mai and Lamphun Provinces, Thailand, from 5 to 10 October 2024. Within the cloud-free analysed areas of about 4,000 km², about 245 km² of land appears to have been affected by flood waters, with around 70 km² of cropland inundated. Based on Worldpop spatial demographic data, about 228,000 people are 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).

**UNOSAT code: FL20210928THA** This map illustrates satellite-detected surface waters in Khon Kaen, Chaiyaphum, Nakhon Ratchasima, and Nong Bua Lam Phu provinces, Thailand as observed from a Sentinel-1 image acquired on 5 Oct 2021 at 18:20 local time and using an automated analysis with Machine learning method. Within the analyzed area of about 40,500 km2 , about 770 km2 of lands appear to be flooded. The water extent appears to have decreased of about 70 km2 since 29 September 2021. Based on Worldpop population data and the detected surface waters in the analyzed area, the potentially exposed population is mainly located in the district of Phimai with ~ 10,400 people, Non Sung with ~ 9,000 people, Mueang Chaiyaphum with ~ 6,700 people, Mueang Khon Kaen with ~ 4,500 people, and Chonnabot Thai with ~ 4,300 people. 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: FL20210928THA** This map illustrates satellite-detected surface waters in Central and Western parts of Thailand as observed from a Sentinel-1 image acquired on 21 October 2021 at 06:09 local time. Within the analyzed area of about 90,000 km2 , about 3,200 km2 of lands appear to be flooded. The water extent appears to have receded of about 70 km2 since 10 October 202. Based on Worldpop population data and the detected surface waters in the analyzed area, the potentially exposed population is 370,000 people mainly located in province of Phra Nakhon Si Ayutthaya with ~ 99,000 people, Suphan Buri with ~ 88,000 people, and Nakhon Sawan with ~ 47,000 people, 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: FL20210928THA** This map illustrates satellite-detected surface waters in Sukhothai, Phitsanulok, Kamphaeng Phet, and Uttaradit provinces of Thailand as observed from a Sentinel-1 image acquired on 2 October 2021 at 06:17 local time. Within the analyzed area of about 4,500 km2 , about 450 km2 of lands appear to be flooded. The water extent appears to have increased of about 90 km2 since 28 September 2021. Based on Worldpop population data and the detected surface waters in the analyzed area, the potentially exposed population is mainly located in the district of Mueang Sukhothai with ~ 14,000 people, Sawankhalok with ~ 14,000 people, Khiri Mat with ~ 7,400 people, and Si Samrong with ~ 7,000 people. 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: FL20240912THA** This map illustrates cumulative detected water using multiple satellites in Chiang Rai Province, Thailand from 1 August to 22 October 2024. Within the boundary of Chiang Rai Province of about 11,600 km², a total of about 875 km² of land appears to be affected by flood waters, with around 700 km² of cropland inundated. Based on Worldpop spatial demographic data, about 94,100 people are 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). This work is the result of collaboration between UNOSAT and GISTDA operating under the agreement of the UNOSAT Rapid Mapping Partners Initiative Programme

**UNOSAT code TC20220928THA, GDACS Id: 1000922** This map illustrates satellite-detected surface waters in Ubon Ratchathani Province, Thailand as observed from a GeoEye-1 image acquired on 20 October 2022 at 10:35 local time. Within the analysis extent of this map, about 120 km² of lands appear to be flooded. Based on Worldpop population data and the detected surface waters within the analysis extent, approximately 32,000 people are potentially exposed to or living close to flooded areas along with 11,330 structures and approximately 400 km roads potentially damaged by flooding. This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to United Nations Satellite Centre (UNOSAT).