UNIVERSITY EXAMINATIONS: 2012/2013
EXAMINATION FOR THE BACHELOR OF SCIENCE IN
INFORMATION TECHNOLOGY
BIT2307 GEOGRAPHIC INFORMATION SYSTEMS
DATE: AUGUST, 2013 TIME: 2 HOURS
INSTRUCTIONS: Answer Question ONE and Any Other TWO Questions
QUESTION ONE
a) Explain the meaning of the following terms with reference to GIS;
i) Projection (2 Marks)
ii) Remote sensing (2 Marks)
iii) Helmert transform (2 Marks)
iv) datum (2 Marks)
b) Briefly describe two types of data used in GIS (6 Marks)
c) Explain the steps used to create a new vector layer in quantum gis (6 Marks)
d) Explain why it’s important that all data loaded into a map is in the same map
properties. (4 Marks)
e) The construction of models of spatial form can be thought of as a series of stages.
Describe the steps involved in this process. (6 Marks)
QUESTION TWO
a) i) Define the term OTF projection. (3 Marks)
(ii) Describe why it’s useful to set the OTF projection on in any GIS project.
(4 Marks)
b) Discuss the ways in which vector data can be acquired. (5 Marks)
c) Identify the classic network-type problems considered during network analysis
(8 Marks)
QUESTION THREE
a) i) Discuss the issues to be considered when scanning maps for use in GIS
(6 Marks)
ii) Highlight the basic spatial entities that may represent features on a map
(4 Marks)
b) By use of appropriate illustration, explain the following types of raster compaction
techniques;
i) Run-length encoding (2 Marks)
ii) Quadtrees (2 Marks)
iii) Chain coding (2 Marks)
c) Discuss the technique used by the Universal Transverse Mercator (UTM) for geo-
referencing (4 Marks)
QUESTION FOUR
a) Describe three types of Data that can be present in a GIS. (9 Marks)
b) Highlight the reasons why attribute data for GIS database may be assigned codes
(3Marks)
c) QGIS supports a number of symbology renderers to control how vector features are
displayed. Describe four such renderers. (8 Marks)
QUESTION FIVE
a) Distinguish between thematic and topographic maps and give an illustration of each
(4 Marks)
b) Compare the relative advantages of raster data with those of vector data . (6 Marks)
c) i) Several errors may arise during the encoding of attribute data. Identify some
these errors. (6 Marks)
ii) Spatial entities are dynamic. Highlight four types of temporal (time) events
which provide an indication of the types of changes that may affect an entity
(4 Marks)
