This map represents suicide rates in the United States from 2002 to 2006, per 100,000 population for ages ten and older. The statistics are age-adjusted to the 2000 population, and I am not exactly sure what that means, since it is not explicitly explained on the CDC site. I think it means those who were less than ten years old in 2000 were not counted though. Also, counties and cities that had fewer than twenty suicides in the study period were not counted, due to being statistically unreliable.
The map appears to be done in some sort of equal area projection, but I do not know this for sure. The use of color is perfect in this chloropleth map, with some sort of off white showing the lowest suicide rates and red showing the highest, with a sensible gradient through yellow and orange. The classes appear to be broken by natural breaks (Jenks), because there are no round numbers in the legend. But these breaks do show trends well on the map.
My only major complaint about the map is that it is somewhat small to be able to differentiate between the counties, and the CDC site does not have a link to a map that is bigger than 556 x 451. Although one can see broad national trends with the map, if someone wanted to look more closely at a region, particularly a region in the eastern part of the U.S., where the counties are far smaller than in the western part, he or she would have to use a different map. It may be unreasonable to use a national map to look at state data, but it seems reasonable that someone may want to still use a national map to look at a region such as New England or the Mid-Atlantic.
The map shows a trend of extremely high suicide rates in the western part of the U.S. and in Alaska and relatively high suicide rates in central Florida and along a belt that runs in a somewhat straight line from western Virginia to northeast Texas. I will not go into the reasons for this, because doing so would go drastically beyond the scope of this map critique. Regardless, these trends should raise a red flag to these regions to ramp up their mental health and public safety departments with more trained personnel and better suicide prevention programs, among other things.
Filed under: GEOG 408 Map Critique | 1 Comment »