Vertically Exaggerating Landforms on Maps Using Shadows

Keywords: terrain representation, landforms, relief shading, shadowing, shaded relief, hillshading, vertical exaggeration
Session Type: Virtual Paper Abstract
Day: Tuesday
Session Start / End Time: 3/1/2022 11:20 AM (Eastern Time (US & Canada)) - 3/1/2022 12:40 PM (Eastern Time (US & Canada))
Room: Virtual 18

Abstract

We explore methods to add vertical exaggeration on planimetric relief maps of terrain. This provides the map user with an impression of the three-dimensional shape of landforms that are properly located. Historically, vertical exaggeration has been confined to the marginalia of planimetric maps, in displays such as vertical two-dimensional topographic profiles or geologic sections. Others have used vertical exaggeration in oblique displays such as block diagrams or panoramic views. We use shadows from a number of directional light sources to show vertical exaggeration on two-dimensional maps. These maps show patterns of grayscale shadowing that change with vertical exaggeration, unlike relief shading (also known as hillshading) where tones vary but the overall patterns do not. By varying the vertical exaggeration of shadowed terrain maps, cartographers can customize displays to highlight or suppress the three-dimensional impression of the map display.