GEOG 480
Exploring Imagery and Elevation Data in GIS Applications

Lesson 8 Introduction


The elevation data products discussed in Lesson 4 provide representations of the three-dimensional landscape in several common GIS data structures: raster, point, and TIN surface. They may or may not include natural and man-made features (vegetation, buildings, bridges, etc.). In any application, the next step is usually to use one or more of those data structures to do some sort of analysis. In this lesson, we will examine several types of analyses that give us additional information about the terrain surface itself. The output from these analyses can be suitable for visualization of topography (contours and shaded relief maps), they can be an interim step in a more complex GIS analysis (slope and aspect maps), or they can predict the way the land and other physical elements of the landscape interact (flood inundation and optical line-of-sight). Since "topography" is defined as "the study of the Earth's surface shape and features,"1 the methods we will study in this lesson are often referred to as "topographic" analyses.

Lesson Objectives

At the end of this lesson, you will be able to:

  • use both imagery and terrain data to create 3D visualization;
  • perform a simple slope and aspect analysis;
  • perform a simple hydrology analysis;
  • perform a simple line-of-sight analysis.


If you have any questions now or at any point during this week, please feel free to post them to the Lesson 8 Questions and Comments Discussion Forum in Canvas.

1Topography. (2009, May 17). On Wikipedia, The free encyclopedia. Retrieved May 2, 2009