Exercise 2: Visualising and examining flooded areas in New Orleans caused by Hurricane Katrina - continued
9. Can you outline the flooded parts of the city?
10. Give a short explanation of how the colours of the image can be used to map the flooded areas.
Supervised classification You will now classify the SPOT image. Open a new RGB view and consider why it could be helpful to cut out some clouds in the east as well as the lake in the south using the “crop” function. Only two classes are interesting in this case: flooded and not flooded areas. You will perform a supervised classification. The first step is to select training fields for the following features:
Flooded
11. Does the classified image depict the flooded areas well? 12. Can you explain why some areas are not mapped accurately? Compare your classified map with maps of the flooding found on the Internet.
13. Can you list some benefits of using remote sensing in flooding situations in other parts of the world? 14. How can satellite images help in the rescue and relief operations following a disaster?
Last update: 17 April 2013
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