GEOG 160
Mapping Our Changing World

8.4 Summary


This chapter introduced the various techniques for representing Earth’s continuous surfaces, both on land and underwater, often derived from a set of measured values at discrete locations. These representations included various methods for gathering, depicting, and computing elevation from both vector and raster-based strategies such as contouring, digital elevation models, interpolation, relief shading, LiDAR, and bathymetry. We manually drew TINs and contours to understand the vector-based approaches towards representing elevation. The first section discussed the history and current use of topographic maps in the USGS’s National Map. Additionally, the accuracy standards and topographic map improvements were detailed based upon the National Spatial Data Infrastructure (NSDI) Framework under the USGS. Finally, the chapter ended with an overview of other surface representations: bathymetry.