Name:
Date:
Per:
Features of Topographic Maps
Background
Topography is, in most general terms, the physical layout of the land. The word topography is derived from the Greek
words topos, which means place, and graphein, which means to write. In other words, topography is writing about or
describing a place. A topographic map (geologists often refer to these as topo maps) shows a number of features. First, it
shows natural land features such as hills, valleys, cliffs, and so forth. It also shows other natural features such as rivers
and lakes. Topo maps also show features constructed by humans such as houses, buildings, developments, bridges,
roads, and even pipelines. The most obvious, and perhaps important feature of a topographic map is that it shows the
elevation of land features relative to sea level. Using a series of standard symbols and practices, mapmakers (also called
cartographers) represent a three-dimensional landscape on a two-dimensional page.
Cartographers use colors to represent different features as well. Green is used to show wooded areas. Bodies of water
(ponds, lakes, rivers, streams) are blue. Roads, railroads, buildings, and bridges are usually black. Cities and towns are
pink. Major roads are red. Contour lines are brown.
Vocabulary
Contour Lines: Equal elevation is represented on a topographic map by lines. In other words, every point on a hill that is
100 meter above sea level will be connected by one contour line. Every point that is 50 meter above sea level will be
connected by another contour line. Contour lines are brown.
Contour Interval: The difference in elevation between two adjacent contour lines is called the contour interval. The
contour interval varies depending on that region being mapped. A mountainous region might have a high contour interval
of 100 meter, which a relatively flat region like a plan might have a low contour interval of 20 meter.
Index Contour: How do you determine the elevation of a particular contour line? Every topographical map has darker,
thicker contour lines that are called index contour. An index contour is labeled with its elevation. First, you find the nearest
index contour and then count up or down by the interval to determine the elevation of a particular contour. For example, if
you need to determine the elevation of a contour that is just above the index contour labeled 200 meter, and you know the
contour interval is 50 meter, you simply add 50 meter to 200 meter for a total of 250 meter.
Materials:
- Topographic Map, Estes park, Colorado
- Topographic Map Rules chart
- Colored pencil
Use the Estes Park, Colorado topographic map and the Topographical Map Rules Chart to identify the following features,
and answer the following questions about the topographic map:
1. What is the contour interval of your map? Show you work!
2. Identify an index contour. Label it on the map. How do you know it is an index contour?
3. Find a stream valley. Label it on the map. What map features indicate that it is a stream valley?
4. Identify a steep hillside. Label it on the map. What map features indicate that it is steep?
5. What map features indicate that the feature in #4 is a hill and not a basin?
6. Identify a more gently sloping area. Label it on the map. How can you be sure?
7. What man-made features are visible on your map? Label them on the map. List them. How can you tell what they
are?
8. Why don't contour lines cross one another?
9. Can the contour interval affect the interpretation of the topography of a particular region? Use examples to explain
your answer.