Topographical Maps

Topographic Maps Topographic maps are detailed maps that show the elevation change and surface features of the landscape.

Colors, symbols and lines are used to show changes in elevation (distance above/below sea level) of the earth’s surface

Contour lines are lines that connect points of equal elevation:

The contour interval (CI) is the difference in elevation between each line: this map’s CI is 25 m.

What is the contour interval for this map? Elevations of points on a topographic map can be estimated using the index contours and the known contour interval. Index Contours: contour lines marked with numbers representing their elevation

List the INDEX CONTOURS on this map. Estimate the elevation of Point C List the INDEX CONTOURS on this map. Estimate the elevation of Point C. What the elevation of the Peak (“X”)? x

A map legend is a list of map symbols and what they represent.

Map Scales A map scale is the ratio between the distance represented on a map and the actual distance on the earth. Example: 1:2000 This means that one centimeter on the map is equal to 2,000 centimeters on Earth’s surface.

Here’s an example of a graphic map scale that shows a line broken into sections that represent distances on earth

Map Scale Problems The scale of a map is 1:24,000 1.) What does this mean? One unit on the map = 24,000 of that same unit in real life! 2.) You measure that two lakes are 7 cm apart on the map. What is their distance in real life? SET UP A PROPORTION. 1/24,000 = 7/x X = 168,000 cm X = 1,680 meters

Use the scales below the map to estimate the distance from point X to Y. Tell students to use a small strip of paper to estimate..

The Relief of a map is the difference between the highest elevation and lowest elevation. What is the relief in the map below? Tell students to use a small strip of paper to estimate.. 600 m 400 m

A PROFILE shows elevation changes if one walked along a specific line on a topographic map. B Tell students to use a small strip of paper to estimate.. 400 m What would a profile of line AB look like?

Profile of Line AB: 600 400 400 A B 600 m A B 400 m Tell students to use a small strip of paper to estimate.. 600 m A B 400 m

The SLOPE between two points on a topographic map is “rise over run” or Change in ELEVATION (vertical) Total land distance (horizontal) If the land distance from A to B is 400 m, what is the SLOPE of line AB? Tell students to use a small strip of paper to estimate.. B 600 m A 400 m