Exercise 5 - Thorung La Region
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|  | Thorong La at 5,416 metres | |
The region around Thorung La is the highest part of the Annapurna Circuit. The trek reaches its highest point at the Thorung La pass at 5,416 m.
Even during the summer, the pass is mainly covered with snow and ice. The sky is clear and cloudless during the dry winter months, but mostly covered in clouds during the summer monsoon period. This characteristic is clearly visible in the satellite images of the Thorung La region.
In the following exercise we will take a closer look at the region, and will try to examine the environment around the glaciers and its geomorphological features.
The first step is to take a closer look at the near-natural colour image for the year 2000 with the number 1 in its name.
Open the following image in LEOWorks:
anapurna_landsat_2000_1N_band_321.tif
Now try to answer the following questions.
Where in the image do we find vegetation?
Which colour represents vegetation? Which types of vegetation can we expect in this region?
First, let's compare the three near-natural colour images with a number 1 in their name with regards to vegetation, snow and cloud cover.
Open the following images in LEOWorks:
anapurna_landsat_1972_N_band_231.tif,
anapurna_landsat_1979_N_band_231.tif, and
anapurna_landsat_2000_N_band_321.tif.
Compare the images with respect to seasonal changes.
Try to answer the following questions:
What percentage of each image is covered by vegetation?
What percentage of each image is covered by snow and ice?
What percentage of each image is covered by clouds?
How well does snow reflect the visual solar radiation? Compare this with water.
Can you see any differences in the reflection characteristics?
To answer these questions, open all spectral bands of the Landsat TM scene of 2000 in LEOWorks. Identify areas covered with snow or ice and water surfaces, and compare the reflection at the different wavelengths.
Arrange the Landsat TM bands into two groups, one with strong reflection of snow and one with strong absorption of snow.
Can you find a relation between the reflection coefficient and the wavelength?
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