Topography is the description of the physical features of a specific place. It refers to natural and man made structures that make up the shape of a landscape including mountains, valleys, plains, lakes, rivers, and vegetation as well as roads, boundaries, transmission lines, and major buildings.
Maps
Topographic maps, often just called topo maps, display the three-dimensional ups and downs of the terrain on a two-dimensional surface. They use contour lines to represent specific elevations. The closer together the lines are, the greater the elevation changes and the steeper the slope.
Scientific Uses
Geologists use topography to understand how a landscape has been formed and where to find resources such as minerals. Ecologists use it to understand relationships within ecosystems, such as the path rainwater and runoff takes through a landscape.
Societal Uses
Emergency responders use their knowledge of topography to plan their routes into and out of wilderness areas, or to predict such things as the path of a wildfire through a forest. Back country hikers also rely on topo maps to explore an area.
Maping the United States
Since 1879, the U.S. Geological Survey (USGS) has been creating topo maps. They created the only uniform map series that covers the entire area of the United States in considerable detail. It contains more than 55,000 maps covering the 48 conterminous States.
Where Can You Get Topo Maps?
Topo maps of the U.S. are for sale from the USGS in paper form, but the National Map provides topo maps, aerial maps and other geographic information on line at http://nationalmap.gov/.
Tags: topo maps, United States