thematic map
See Also : choropleth map
[map design] A map designed to convey information about a single topic or theme, such as population density or geology.
"There has been some debate in the literature over the definition of a thematic map although there is now general agreement that thematic maps show data related to a particular theme such as soils, climate, or population. This includes univariate or single variable maps, special purpose maps and derived maps.
Univariate maps show the spatial distribution of a single variable such as precipitation, population or crop yields. Usually these maps are drawn at a relatively small scale since the emphasis is on portraying the distribution of the selected phenomena. Positional accuracy is not a primary concern although the maps should include enough base map information so that the map reader can easily identify the area being represented and can relate the spatial pattern to recognizable physical and cultural features.
Special purpose maps are often designed for use by skilled users within a discipline. Examples include geological maps which show the lithology or bedrock structure of an area, soils maps, hydrology maps, or weather maps. These maps typically represent the distribution of several related variables simultaneously.
Maps of physical (natural or cultural) phenomena show the data/attributes at the place where these phenomena actually exist. Derived maps are based on statistical data and often represent distributions which are based on areal data rather than data that exist at a point. Maps which represent proportions, rates or densities are examples of derived maps: e.g. crop yield in bushels per sq. km., dairy cattle per sq. km., unemployment rates, or population densities. Derived maps may also show relationships between variables, e.g. level of unemployment as related to cod stocks in Newfoundland or per capital income as it relates to level of education.
Thematic maps are designed to speak to a specific audience. They are intended to convey a message to the audience. Simple thematic maps can often be understood at a glance although thematic maps which attempt to portray the relationship among several variables or represent complex spatial patterns may require more careful examination and analysis."
GloED Thematic Maps
Click here to view a screen capture of a thematic map.
Mapping
Once a scenario is defined using GloED and an emissions inventory is calculated for it, the user is ready to create a map that reflects the results of the inventory. The map will appear on the computer's video monitor, and each country is displayed in a color that corresponds to the scenario output. A legend is provided in the lower part of the map to enable definition of the quantities associated with the colors. A screen capture of a map of emissions from rice growing is shown above.