Exercise 1: Exploring the volcano - continued


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Image > Combine from > RGB > 4-5-3
Image > Combine from > RGB > 7-4-2


  
 
 
FCC 4-5-3 of the Landsat image of 1999
 
 
The band 4-5-3 combination with two IR bands highlights different details to the ones in the previous combinations. Vegetation types can be distinguished and are displayed in shades of orange/brown/green (as there are infrared bands assigned to red and green), urban areas in shades of light purple, water is dark (due to the infrared absorption) and can clearly be delineated from land, and the volcanic plume disappears.




9. How does the lava appear in this FCC? Can you distinguish different ages of lava? If so, why?

10. What are the light green pixels in the area of the summit? Were they visible in the previous combinations? Why or why not? Think about the mid-IR band.


 
 
   
FCC 7-4-2 of the Landsat image of 1999
 
The band 7-4-2 FCC provides a natural appearance. Healthy vegetation is bright green, grassland is green, soils have multiple colours, bare soil is pink, and sparse vegetation is orange. Fires would appear red.








11. What are the red pixels in the area of the summit? Why do they appear red?

12. Play with different colour combinations.

13. Try to identify lava and infrastructure (cities, villages, roads).

14. With which combination can you best identify volcanic lava?

15. How far does volcanic lava extend? Can you estimate when this occurred? (use the eruptions table in the introduction)


 
 
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Last update: 17 April 2013


Etna

 •  Introduction (http://www.esa.int/SPECIALS/Eduspace_Disasters_EN/SEMX0BMSNNG_0.html)

Change Detection and Hazard Assessment

 •  Worksheet introduction (http://www.esa.int/SPECIALS/Eduspace_Disasters_EN/SEMD4BMSNNG_0.html)
 •  Exercise 1: Exploring the volcano (http://www.esa.int/SPECIALS/Eduspace_Disasters_EN/SEMMTBMSNNG_0.html)
 •  Exercise 2 : Visual interpretation using terrestrial photographs (http://www.esa.int/SPECIALS/Eduspace_Disasters_EN/SEM1MJMSNNG_0.html)
 •  Exercise 3: Lava detection: crisis images and maps (http://www.esa.int/SPECIALS/Eduspace_Disasters_EN/SEM4NJMSNNG_0.html)
 •  Exercise 4: Hazard assessment: GIS can help! (http://www.esa.int/SPECIALS/Eduspace_Disasters_EN/SEM6DKMSNNG_0.html)

Eduspace - Download

 •  Etna_Landsat_GIS.zip (http://esamultimedia.esa.int/docs/eduspace/Volcanoes_Exercise_Data_1.zip)

Eduspace - Software

 •  LEOWorks 3 (http://esamultimedia.esa.int/multimedia/LEOWorks3.exe)
 •  LEOWorks 3 Tutorial (http://esamultimedia.esa.int/multimedia/eduspace/leoworks3-tutorial.pdf)