Despite the reluctance of the Myanmar military junta to let international aid organizations into the country, the SPOT 4 and SPOT 5 satellites are revealing the effects of Cyclone Nargis in and around the capital city Rangoon.

On the morning of Friday 2 May, on Myanmar’s south coast, little did local populations know that the heavy rains were just a foretaste of the full-blown tropical storm that would follow. Reports of Cyclone Nargis describe a three-metre wall of water surging inland over farmlands and homes on the Irrawaddy delta, right up to the capital city Rangoon. But because the government has refused to let international aid teams into the country, assessing damage and the needs of affected populations is proving an uphill task. 
 

To gauge the extent of the damage caused by Cyclone Nargis in Rangoon, the international community needs a tool to rapidly map and identify urban areas and flood zones. 
 
 

A SPOT 5 satellite image acquired 2 March 2008 was delivered at the request of the members of the International Charter on Space and Major Disasters. This archive image shows residential urban areas. A SPOT 4 image was acquired 6 May 2008, four days after the cyclone. This recent image reveals the extent of floods in and around the city of Rangoon.
 
 

A map was produced in two steps: first, urban areas were identified on the SPOT 5 archive image; then, residential areas were delimited (yellow lines) and rivers extracted (blue) before receiving the tasked image.

 
As soon as the tasked SPOT 4 image was available, radiometric classification highlighted flood zones (in green). Urban residential areas and rivers were overlaid to reveal the flood extent. 
 

The SPOT 4 and SPOT 5 satellites were able to deliver timely information on flood extent around Rangoon to international aid teams soon after the passage of Cyclone Nargis, even though Myanmar’s borders remained closed.