which thematic map is appropriate

Question

Hi

I have prepared maps, based on impact due to development project on some socioeconomic attributes like, landuse value, employment opportunities, crime and criminal activities, etc. I thought that, choropleth mapping will be appropriate for visualization of such attributes, as impacts on these attributes (due to a development project) have been graded as ' No impact, moderate impact or high impact' , which I guess indicates intensity of impact.

is my choice right?, as I realize that choropleth maps also indicate rates, like population density.

hhet · Answer

some questions you might ask yourself before deciding on the choropleth route.

1) is the phenomena evenly distributed throughout the enumeration area?   i f the density of the phenomenon is more not less uniform then  a choropleth map is appropriate

2)does the phenomenon change at enumeration unit boundaries? if so, then choropleth is appropriate.

3) is there a significant variation in  size and shape of the enumeration units? If so, choropleth map may not be advised

When you select data to include on a choropleth map you must be sure to adjust the raw totals. do the raw totals involve area?

you might consider mapping rates

All standardization undertakings have their own computational methods.

even though all computational techniques involve ratios, ratios, by themselves are usually not  enough

of course, each standardization approach would lead to a different map

if you map raw totals , use proportional symbols

The answers to these and other questions about designing and constructing  the map   will help determine how accurate your map is using a choropleth technique

h

blake.terhune · Answer

I think you're on the right track. If you've got discrete categories like that with only a few categories, a choropleth map is probably your best bet.

If you already have those impact descriptions attributed in your data, you can symbolize using categories and pick the field. If you've got a range of impact values and want to group them into those impact categories, symbolize by quantity and classify the categories however you see fit (just be careful not to lie with statistics).