Map Animation

History of Map Animation

Before computers and their related technologies became commonplace, geographers and cartographers had used techniques such as hand drawings of each map, and a camera recorded each map frame of the animation. Despite these early [Page 1826]technological challenges, geographers advanced the technology for animating maps. Norman Thrower, as early as in the 1950s, promoted the possibility and promise of animating maps for showing the distribution of the conversion of forests to agricultural land, the spread of populations over time, and the change in political boundaries. One of the earliest computer map animations was a three-dimensional portrayal of a population growth model of Detroit, Michigan, by Waldo Tobler in 1970.

Further developments in map animation were inhibited by the high costs of reproducing graphic/color images, the high cost of computer hard disk space, and the lack of animation software development. However, with continuing technological advances, the increase in the number of users, and the decline in the cost of computing equipment such as hard disk storage, computing technology use has blossomed in the past 20 years, and map animation has become much easier to design, use, and distribute. The technological advances in computing power and speed and animation software have allowed geographers to break through the early limitations of cost and time to display a plethora of information on maps.

Animations and their Visual Variables

David DiBiase and his colleagues in the early 1990s showed how specific visual variables for static maps can aid in the development of map animations. Animating maps requires knowledge and programming of visual variables that involve duration, rates of change, and the order the maps are displayed in. Duration is the length of time a map is displayed. The rate of change is defined by m/d, where m is the magnitude of the change and d is the duration of each frame. By either increasing the magnitude or decreasing the duration, the animation would speed up, or by decreasing the magnitude or increasing the duration, the rate of change would decrease. The order is the sequence in which the map frames are displayed. In Figure 1, A shows the slower and the faster rates of change related to geographic position, and B shows a series of maps with increasing rate of change related to circle size.

Animation Categories

Map animations that emphasize change may display demographic shifts in the U.S. population center after each decennial census count. Animations that emphasize location may display the world map and the global locations of active volcanoes over a certain time period. Animations that emphasize attribute differences in the Earth-Sun Geometry would display the Earth's seasonal relative position to the sun. Many of these animations are helpful didactic tools to teach and visualize the changeability of a dynamic process, especially when the phenomenon is much larger than the human scale.

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