GIS Applications in Civil Engineering- QGIS Tutorial on Surface Analysis and Topology Checking

Surfaces are commonly used in a geographic information system (GIS) to visualize phenomena such as elevation, temperature, slope, rainfall, and more.

This tutorial also touches on topology. A GIS topology is a set of rules and behaviors that model how points, lines, and polygons share coincident geometry. For example: Adjacent features, such as two counties, will have a common boundary between them. Also connectivity between lines can be defined by rules that indicate dangles.