Exercise 5: Measurement of area


Digitising a glacier outline
 
Digitising a glacier outline
 
 
Measure glacier retreat using the Measure Tool.

Compare the area of a glacier system in 1988 and in 2010. Choose a small glacier system that seems easy to outline. Open the Measure Tool for the 1988 image and digitise the glacier outline. Write down the area (surface). Do the same for the same glacier system in the 2010 image.

1. How did the area change in absolute values and in percentage?

Digitising glacier outlines from satellite images is not always easy and clear, and includes uncertainty and errors. Compare your area and area change results with the other students in your class who digitised the same glaciers.

You can also repeat the above procedure several times and average your results. Be aware that larger glacier tongues can be covered with moraine material at the lower end, in the ablation zone.

2. How large are the deviations between the repeat measurements?

 
 
 
Last update: 16 April 2013


Climate change and glaciers

 •  Introduction (http://www.esa.int/SPECIALS/Eduspace_Global_EN/SEMJWGH2SDH_0.html)
 •  Background (http://www.esa.int/SPECIALS/Eduspace_Global_EN/SEMJXGH2SDH_0.html)

Exercises

 •  Worksheet introduction (http://www.esa.int/SPECIALS/Eduspace_Global_EN/SEM5ZGH2SDH_0.html)
 •  Exercise 1: Inspection of true colour RGB composites (http://www.esa.int/SPECIALS/Eduspace_Global_EN/SEMIAJH2SDH_0.html)
 •  Exercise 2: Animation (http://www.esa.int/SPECIALS/Eduspace_Global_EN/SEMUEJH2SDH_0.html)
 •  Exercise 3: Band Arithmetic (http://www.esa.int/SPECIALS/Eduspace_Global_EN/SEMMFJH2SDH_0.html)
 •  Exercise 4: GIS (http://www.esa.int/SPECIALS/Eduspace_Global_EN/SEMDHJH2SDH_0.html)
 •  Exercise 6: Multitemporal analysis (http://www.esa.int/SPECIALS/Eduspace_Global_EN/SEMDKJH2SDH_0.html)
 •  Conclusions (http://www.esa.int/SPECIALS/Eduspace_Global_EN/SEMFTKH2SDH_0.html)

Eduspace - Software

 •  LEOWorks 4 (MacOS) (http://leoworks.asrc.ro/download/leoworks.app.zip)
 •  LEOWorks 4 (Linux) (http://leoworks.asrc.ro/download/leoworks.jar)
 •  LEOWorks 4 (Windows) (http://leoworks.asrc.ro/download/leoworks.exe)

Eduspace - Download

 •  Andes_images.zip (http://esamultimedia.esa.int/docs/eduspace/Andes_images.zip)
 •  GoogleEarth file (http://esamultimedia.esa.int/multimedia/GoogleEarth_file eduspace_glacier.kmz)