What is a topographic map?

    "A map is a representation of the Earth" (USGS, 1999). However, topographic maps, sometimes called a 'topo map,'  have unique characteristics. They represent Earth's surface with contour lines. "Contour Lines are lines connecting the points on a land surface that have the same elevation" (Benny Chow, 1998). Further, topographic maps show many others useful features, such as symbols of buildings, landforms, and elevation. Topo maps are used for many purposes. They represent not only the geographical area of a specific place, but can be used as a tool for land navigation, such as hiking.

Reading a Topographic Map

    To read the topo map, "interpreting the colored lines, areas, and other symbols is essential" ( USGS, 1999). Contour lines, longitude and latitude, and map legend are among the many aspects of a topographic map, and are the basic guidelines to understand the topographic map.

       Contour lines show elevation of the landscape. According to Matkoski (1999), "Contour lines are imaginary curved lines that run along the ground at equal points of elevation." Contour lines make it possible to represent a three-dimensional elevation (mountain) on a two-dimensional surface (map). The distance between each contour line is called the contour interval. Contour interval is stated in the map legend, along the bottom of the map. Each map has a contour interval, due to the characteristics of the landscape itself.

    Longitude and latitude together represent the values for a position in a global perspective. "Longitude is a series of imaginary lines radiating from the North and South poles. There are 360 degrees of longitude. Latitude is a series of belts that circle the Earth. The Equator is 0 degrees, and the north pole is 90 degrees north latitude" (D. Latimer, 1999).

    One of the most important aspects of a topographic map is its legend. It shows many great details of the topographic map, such as latitute and longtitude or the global position aspect, the contour interval of the map, and the location of the map. Rick Curtis (1998) embedded the many details of map legend in his book, entitled The Backpacker's Field Manual. Below are map details taken from Rick Curtis (1998) publication:

1. Map name
2. Year of Production and Revision
3. General Location in State
4. Next Adjacent Quadrangle Map
5. Map Scale
6. Distance Scale
7. Contour Interval
8. Magnetic Declination
9. Latitude and Longitude