Topographic Maps Topographic Maps show the surface features of an area is about…..

Contour Lines Contour Lines are imaginary lines that join points of equal elevation above or below sea level Contour Line Link

Contour Lines Equal elevation

Rules of Contour Lines Never cross each otherNever cross each other Connect with themselvesConnect with themselves Get closer together as land gets steeperGet closer together as land gets steeper Get further apart as land gets flatterGet further apart as land gets flatter

Contour Interval The distance that separates contour intervals The change in elevation from contour line to contour line is called the contour interval

Contour Profile The shape you would see if were sliced along a line

Gradient The gradient of a mountainside is a measure of its steepness

Relief The relief of a contour map is the difference between its highest and lowest points 500 m (950 m – 450 m) [Accept all reasonable estimates.] 500 m (950 m – 450 m) Contour Interval = 50m

Important thing to remember …. Topographic maps can be used to identify land and erosional features

Let’s take a walk up a hill!

We’re now at an elevation of 100 meters. 100m

Let’s keep going! 100m

Now we’re at 200m. 100m 200m

Shall we march on? 100m 200m

We’ve made it to 300m! 100m 200m 300m

On to the peak! 100m 200m 300m

We’re on the peak, but what’s our elevation? 100m 200m 300m

Any ideas? 100m 200m 300m Let’s add contour lines for every 50 meters and see if that helps.

100m 200m 300m We know that we are above 350m, but less than 400m. 50m 150m 250m 350m

100m 200m 300m Let’s head down the hill, it’s getting late! 50m 150m 250m 350m

100m 200m 300m Now what’s our elevation? 50m 150m 250m 350m If you said somewhere between 200m and 250m you are right!

100m 200m 300m Let’s try this again! 50m 150m 250m 350m

100m 200m 300m What’s our elevation now? 50m 150m 250m 350m If you said 50m or just under, you’re right!

Let’s now look at the same hill, but the way we might see it from an airplane!

Each color change represents a 50 meter increase.

Now, let’s try the same hike! Our elevation is 0 meters.

Now what is our elevation?

If you said more than 150 meters, but less than 200 meters you’re right!

Let’s go a little higher.

Think you know our elevation now? More than 300meters But less than 350meters

If we were standing on the peak, what would be our elevation? More than 350 meters, less than 400 meters

Let’s head down hill.

Know our elevation?

More than 100 meters, less than 150 meters

Let’s see what you know. 400m 800m 1000m 1200m A B C D E F 600m

1. Could the elevation at the peak (B) be 1410 meters? 400m 800m 1000m 1200m A B C D E F 600m No : The elevation must be under 1400 meters, but over 1300 meters.

2. What is the elevation at (E)? 400m 800m 1000m 1200m A B C D E F 600m About 400 meters

3. If you walked a straight line from (D) to (C) would you walk over a ridge or down a valley? 400m 800m 1000m 1200m A B C D E F 600m Down a valley: If the contour lines point up the slope it’s a valley, if they point down the slope it’s a ridge.

4.Just looking at the map, would it be easier to head down from the peak going East, or going North? 400m 800m 1000m 1200m A B C D E F 600m E N S W East: When contour lines are close together that means there is a steep slope, the further apart the lines, the more gentle the slope and therefore an easier walk! Go east!

What land feature is represented in the picture below? Depression

Valley

Ridge

Hill

Contour Practice 1.What is the contour interval of the map at left? 2.What is the elevation of point A? 3.What is the elevation of point B? 4.What is the elevation change between A and B? 80 m 320 m 880 m 560 m

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