A New Approach for Visualizing the Spatial Distribution of Population Over Time

Abstract

This research explores a new method of visualizing population dynamics using a static map medium. This involves the calculation of vectors that indicate the change in mean population center in a study area over a period of time. I calculate these vectors by examining the change in mean population center inside a moving window from one time period to the next. Using different sizes of these moving windows will yield results that tell different stories about the dynamics in the study area. The second component of this approach involves developing methods of displaying these vectors—collectively, a vector field—on a static map. Using the hue, saturation, and value (HSV) color model, I assign the hue component of color to the direction component of the vector and the value component of the color to the magnitude component of the vector. A significant challenge arises in assigning hues to particular directions. I explore this by conducting a study of respondents’ association of hue with the cardinal and intermediate directions. Based on the results of this survey, I have developed my own system of hue-direction for display of vector fields. Finally, I assess the methodology by conducting a survey that presents the respondents with a few example maps and asks several questions to determine if the respondent is able to correctly read and interpret the maps. Complemented with more traditional visualizations of population change, this contribution should enhance visualization of population dynamics with static media.