Published on 16 July 2021
From 13 – 15 July, exceptionally persistent and heavy rainfall, caused by a stationary low-pressure area over southern Germany, fell over the Ardennes, Eifel, and surroundings in Belgium, the Netherlands, and Germany. In many locations it rained almost constantly throughout these 3 days and rain totals locally became > 200 mm, an amount that normally falls in about 3 months.
The radar instrument on-board the Copernicus Sentinel-1 satellite, capable of observing the Earth under cloudy circumstances, shows the effects of this exceptional rainfall episode. The slide animation below alternates between Sentinel-1 images of 9 and 15 July 2021 (see in the TerrascopeEO viewer). The flooded areas of the Meuse river and her tributaries are clearly visible as increased blue regions in the 15 July image.
The TerraFlood service, an initiative of the Flanders Environment Agency (VMM), Ghent University, and VITO, offers the possibility to generate comparable flood mapping images. This free application provides a clear flood mapping within 24 hours after occurrence and provides additional flood dynamics and frequency information. This information is very valuable to e.g. governments and companies involved in quantitative water management, the agricultural sector, and environmental agencies.
We invite you to watch this short video where Beniamino Abis, an expert in Climate and Earth Observation, answers the questions “Why are storms so prevalent in recent times?” and “Why does rain accumulation cause flooding of the streets?”. This video is part of the "Ask a scientist" webinar organised to support teachers and teams of students participating in ESA Climate Detectives 2020-2021.
Terrascope (2021, July 15) – Monitoring flooded areas with Sentinel-1 satellite data
ESA Climate detectives
Copernicus Emergency Mapping Service - Flood in Belgium
A slow moving cyclone brought devastating floods to parts of north west Germany and other parts of western Europe in July 2021 (EUMETSAT)