Maps

Chloropleth Map:

 

 

 A Chloropleth map is a "thematic" map. The map uses colors, shades, patterns...to illustrate statistical measurements. It is a good visualization of variation across a geographic field. This Chloropleth map from the CDC uses shades of blue to illustrate obesity--the darkest blue being the highest prevalence.

Dot Density Map:

 

A Dot Density  map uses a symbol, generally a dot, to illustrate the distribution of some phenomena. Here the Dot Density map shows the total number of West Nile Virus cases in the U.S. from 1999-2008. The density of the dots allows us to understand the magnitude of the virus. 

Proportional Symbol Map:  

A Proportional Symbol map uses different sized symbols to represent data. Here the size of the cows increase as the number of cows increase---I know this map seems random, but cows are CUTE! and who doesn't love a good glass of milk?!? :) 

Topographic Map:

 

A Topographic Map is very detailed using contour lines. This is a map of Chattanooga.

Environmental Sensitivity Index Map: 

 

An ESI map is used to illustrate coastal shoreline sensitivity, for example, to be used in showing oil vulnerability. This map is of part of the Point Reyes National Seashore.