Wednesday, June 6, 2012

Maps

Choropleth Map


     Choropleth maps are shaded or patterned according to measurement being displayed within that region. The map above uses different shades of red and pink to indicate the average percentage of both deaths among children under the age of 5 due to HIV/AIDS and the population undernourished between 2004 and 2006, across Africa.

Dot Density Map

     Dot density maps use small dots to represent a specific portion of the population.  The map above reflects the distribution of poor individuals outside of metro or large cities, in 2004.  Each dot represents 200 people.  You will notice that near larger cities (Atlanta, New York, Los Angeles, Miami, etc.) there are no dots, but in areas outside of those cities, especially east of the Mississippi River, there are greater concentrations of blue dots or greater populations of poor individuals.

Proportional Symbol Map

     Proportional symbol maps use symbols of different sizes to represent data/statistics pertinent to different areas.  The map above is a display of the homeless population, by state, in 2009.  Unlike the dot density map, this particular map reflects greater concentrations of homeless people in states where major cities are located (New York-New York City, Florida-Miami, California-Los Angeles, San Fransico, San Diego, etc.)  The larger circles represent a greater homeless population, in that state.

Topographic Map


     Topographic maps display both natural and man-made features.  Through the use of contour lines, these maps display changes in elevation of a particular area.  This topographic map shows the elevation changes of Stone Mountain and the area immediately surround the landmark.  You will notice, at the location of the mountain, there are a greater concentration of contour lines as you make your way to the center or top of the mountain.

Environmental Sensitivity Index Map


     Environmental Sensitivity Index maps provide a concise summary of areas that would be directly and most affect, in the event of an oil spill.  The above map shows the coast line of Kenya, located at its south east border.  According to the map and legend, the waders would be in the most danger, should an oil spill take place.