Question 5
(7)
a) What is a vegetation index?
b) Why are vegetation indices used?
c) Which is the most used vegetation index?
d) Why do areas with no vegetation have a low vegetation index?
Question 6
(9)
Electromagnetic radiation consists of electromagnetic waves characterised by wavelength and
frequency.
1. Explain wavelength and indicate the measurement unit.
2. Explain frequency and indicate the measurement unit.
3. What is the relation between wavelength and frequency? What is this expression
representing?
4. Give an example of electromagnetic radiation with a large wavelength.
5. Give an example of electromagnetic radiation with a high frequency.
Question 7
(21)
Indicate if the following statements are True or False. If false. correct the statement.
1. Thermal radiation from animals and humans is emitted in the visible light range.
2. The distance between two meridians of longitude is a constant (always the same).
3. Lines are composed of at least three vertices that are connected.
4. Each cell of a raster image stores a single value.
5. Green plants absorb green light.
6. The location 1,215,000 m E; 581,355 m S is expressed in geographical coordinates.
7. Thermal radiation can be carried through a vacuum.
8. It is best to use satellite images of the warm, dry season to map vegetation in Namibia.
9.
Terrain
slope
can
be
expressed
in
degrees
(0
)
or
in
per
cent
(%).
10. Google Earth is a GIS.
11. The EISis a local data repository that contains GISdata.
12. A map scale of 1:250,000 is larger than a map scale of 1:25,000.
13. The location with latitude 15.55 and longitude - 22.15 is south of the equator.
Question 8
(5)
During a guest lecture, the use of hyperspectral satellite images for research in the
ProNamib Nature Reserve was demonstrated.
1) What is a hyperspectral image?
2) How can the data be verified in the field?
3) Give an example of a hyperspectral satellite.
4) What advantage has hyperspectral data compared to multispectral data for
rangeland management?
2