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Flood mapping using SAR-imagery

(June 2014) Flood mapping using SAR-imagery has been demonstrated previously, using various techniques. The recently launched European radar satellite Sentinel-1 has the ability of facilitating future operational flood mapping based on fully automated processing.

Kongsberg satellite Services (KSAT) has in cooperation with the partners Norwegian Computing Center (NR) and Norwegian Space Centre developed a prototype product for operational flood extent mapping based on automatic detection that has been demonstrated for the Norwegian Water Resources and Energy Directorate (NVE).


KSAT product processed by Norwegian Computing Center based on Radarsat (2014)-2 Data and Products © MacDONALD, DETTWILER AND ASSOCIATES LTD., – All Rights Reserved and RADARSAT is an official mark of the Canadian Space Agency (2014).
The image: Floods in Troms – Image by Radarsat-2 – June 07, 2014 05:19 UTC. Image: NR, KSAT, NRS, MDA.
Areas affected by flooding are colored in dark red

KSAT’s Project Manager Hans Eilif Larsen says that in the future there will be regular and frequent monitoring of Norway from radar satellites by Sentinel-1 and other SAR missions. Potentially flooded areas may be reported and monitored operationally, not only as demonstrations, already from next flooding season.
bq. We try to show that it is possible, says Larsen.

The use of radar satellite data provides the ability to cover larger areas than by aircrafts and UAVs as today, and also provides authorities and other stakeholders with an overview of flood affected areas even though it could be bad flying weather, which is often the case with flood events caused by heavy rain, says Larsen.

KSAT product processed by Norwegian Computing Center based on Radarsat-2 Data and Products © MacDONALD, DETTWILER AND ASSOCIATES LTD., – All Rights Reserved and RADARSAT is an official mark of the Canadian Space Agency (2014).
The image: Flood at Lake Øyeren. Image by Radarsat-2 – May 27 2014. Image: NR, KSAT, NRS, MDA.
Areas affected by flooding are colored in dark red.

The current flood warning system is based on models. These can only estimate how floods turn out. Larsen says that satellite monitoring will provide an instant observation, not a calculated estimate of how flood evolves.
The first example of how this can be applied was demonstrated through radar images of the flooding taking place in Norway recently.

This first demonstration shows how an operationalised service can be used in flood mapping, says senior adviser Dag Anders Moldestad at the Norwegian Space Centre.

Moldestad says that through the major European Earth Observation program Copernicus Norway will have frequent access to radar images when the satellite Sentinel-1 enters the operational phase at the end of the summer.

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