Product ID: 3398 - English
Published: 22 Oct, 2021
GLIDE: FL20210928THA


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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.
Satellite Data(1): Sentinel-1
Imagery Dates : 20 Oct 2021 at 23:09 UTC
Resolution: 10 m
Copyright: Contains modified Copernicus Sentinel Data [2021]
Source: ESA
Source: ESASatellite Data(2): Sentinel-1
Imagery Dates : 10 Oct 2021 at 11:28 UTC
Resolution: 10 m
Copyright: Contains modified Copernicus Sentinel Data [2021]
Source: ESA
Reference water : ESRI 2020 Land Cover
Waterways: OpenStreetMap
Road data: OpenStreetMap
Background: ALOS Global DSM
Insets: Jilin-1/20 Oct 2021
Source : ChinaGEO / NODA / CGSTL
Analysis : United Nations Satellite Centre (UNOSAT) Machine learning method
Production: United Nations Satellite Centre (UNOSAT)