Land Navigation
On land
we use maps to find our way around. Whether we are in a car or on a bike
we can use a map to find where we are going. A map is a set of points,
lines, and areas all defined both by position with reference to a coordinate
system and by their non-spatial attributes. Maps are the world reduced
to points, lines, and areas, using a variety of visual resources: size,
shape, value, texture or pattern, color, orientation, and shape. A thin
line may mean something different from a thick one, and similarly, red
lines from blue ones.
Maps have
been around for many years. Evidence of mapmaking suggests that the map
evolved independently in many separate parts of earth. Marshall Islanders
made stick charts for navigation. Pre-Columbian maps in Mexico used footprints
to represent roads. Early Eskimos carved ivory coastal maps. Incas built
relief maps of stone and clay. Chinese literature contains references to
maps as early as 7th century B.C.
How are maps used?