Elevation of given points on topographic maps

Mr. DeMarco

Sample Topographic Map:

100200

300400

500

600700

800

837

What could be a possible elevation of point x?

Let’s turn this map sideways to get a better look:

100

400300

200

500600

700800

837There is the point, “x” that I wanted to find….

Close-up of the same map:

300

400

Because “x” is not specifically labeled, we don’t know its exact elevation, but we do know that “x” is between and ft.

So…what could the value of “x” be?

If it was 300ft, it would be directly on the 300ft. contour line.

If it was 400ft, it would be directly on the 400ft. contour line.

That leaves us with a range of values that “x” could be.

100200

300400

500

600700

800

837

We know what X could be!

100200

300400

500

600700

800

837

What could be a possible elevation of point x?

100200

300400

500

600700

800

What is the highest possible elevation of point x?

Answer on next slide

100

400300

200

500600

700800

1. We know the contour interval is 100ft2. That means that if there were to be

another contour line above 800ft here, it would be 900ft. But there is not!

3. So we know that it could be up to 899ft, and still be shown the same way on this map!