Assignment 3: Exploring Raster and Vector Data
Due February 3, 2012
Introduction
As you know form this week’s lectures, in order to realize the analytical capabilities of GIS the data on
spatial entities need to be represented in a way that a computer would ‘understand’. Deciding on a
spatial model that would capture and convey the characteristics of spatial entities the best possible way
is a crucial step in this process.
This assignment will help you to solidify your understanding of the raster and vector data models as well
as to get a feel for these types of datasets.
Section 1: Theory
Textbook readings: Chapter 3 and lectures
Answers to these questions can be found in the textbook, in the guided tutorial, or online.
(each question is worth 2 marks)
1. Describe the three stages involved in creating a GIS model.
2. Identify (at least) 2 advantages and 2 disadvantages of the vector spatial data model. What
types of features are better represented using this approach?
3. Identify (at least) 2 advantages and 2 disadvantages of the raster spatial data model. What
types of features are better represented using this approach?
4. What is the difference between data models and data structures in the context of GIS?
5. What are the issues that may need to be addressed when choosing how spatial features should
be represented in a GIS?
6. One of the possible sources of data for a DTM is contour maps. What are contours?
Section 2: Guided Tutorial
In this part of the assignment you will continue working on the Getting Started with GIS ESRI web course
you began working on in Assignment 1. The introductory portion of this module provides a brief review
of the concepts familiar to you from the lectures and from the reading the text. However, it also
provides some useful information that was not covered in the lectures this week, e.g., spatial
referencing of raster datasets.
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In the practical part of this module, you will explore vector and raster data for a portion of Yellowstone
National Park. Instead of creating map showing results of your work (which does not make sense in case
of this exercise), when you complete the exercise you will answer two additional questions about the
characteristics of data you were working with.
Instructions
1. Go to: http://training.esri.com and select My Training from the left-hand menu.
2. Select My Virtual Campus Courses and then log in using the username and password you created
earlier.
3. Under Courses in Progress heading, click on the title of Getting Started with GIS course to get back
to this course.
4. In Module 2, complete the GIS data section.
5. If you have not done this before, save the data provided for this course on your H:\ drive.
6. After you have completed the Explore Raster and Vector Data exercise, please provide answers to
the following questions below:
Question 7
2 marks each
How many columns and rows is Elevation raster dataset comprised of? What is its cells size?
Question 8
How many columns and rows is Cover types raster dataset comprised of? What is its cells size?
Section 3: On your own
In this part of the assignment, you will practice applying the skills you learned in the guided tutorial
section above as well as in the other assignments you have done so far in this class. You will be working
with sets of raster and vector data modeling terrain of Saskatchewan, which are located in
T:\Class\Geography\geog303\Assignment 3 folder.
Instructions
1. If necessary, start ArcMap and add the data from the Assignment 3 folder. This folder contains the
following files:
province.shp – a shapefile containing Saskatchewan provincial boundary
contours.shp – a shapefile containing contour lines modeling Saskatchewan terrain
dm_sk – a digital elevation model for Saskatchewan
major_cities – a shapefile containing location of Saskatchewan major cities
Start with adding the province shapefile followed by the rest of the datasets in this folder. You will
have to perform visual transformations (re-projecting ‘on the fly’) of contours, dm_sk and
major_cities datasets to match the coordinate system of the province shapefile.
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2. To make your map more visually appealing, change the coordinate system of the data frame to
NAD_1983_CORS96_UTM_Zone_13N. (Hint: look for this option in Predefined  Projected
Coordinate Systems  UTM).
3. Examine the contours and dm_sk layers. Using the skills you acquired so far, compare and contrast
the two data sets and provide your answers in the following table:
Data set
Data model
Feature type
(if applicable)
Cell size (if
applicable)
Elevation of
Regina, m
Elevation of
Moose Jaw, m
Contours
Dm_sk
Question 9
Submit the table with your answers
Question 10
In your opinion, which data set provides a better model of terrain in Saskatchewan?
5 marks
1 mark
4. Label the features in the cities layer (Hint: right-click on the name of the major_cities layer and look
for a suitable option.)
5. After you have labelled the major cities, create a map layout showing the contours layer and digital
elevation model layer with provincial boundary layer at the bottom for a better appearance of the
map. For this map, select LetterPortrait template from list on the Traditional Layouts tab of the
Select Template window. This window opens when you press a corresponding button
usually
located in the right-hand corner of the ArcMap window. You may have to adjust the size of the map
elements. Add you name to the layout and print it using a colour printer; or export the map as a .jpg
image, insert it into a Word document and submit electronically.
Question 11
Submit your digital terrain model map.
5 marks
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