DO NOW: Describe this picture How would you describe this picture to me? How could you accurately tell me about this picture?

Topographic (contour) maps MAPPING FIELDS Topographic (contour) maps

Does this help? They are above sea level. Tell me the name used here for height. (Elevation). Elevation: height from sea level. Mt. Riddle is 3047’ Mt. Ginger is 3998’ and Mt. Tipster is 2186’

SEA LEVEL

RISING WATER Imagine someone flew to this island and ran around the shoreline marking sea level with brown paint, labeling it 0’. Each morning she awoke to discover the water level had risen another 500’ and each morning she ran around the island marking the levels with her brown paint and labeling them accordingly

Contour Lines Remarkably, on the eighth day she rose and discovered that just as mysteriously as the water had risen, it had fallen back down to it’s original level. Now all the lines marking the different levels could be seen. Isolines are lines that connect points of equal value on a map. When working with contour (topographic) maps these isolines are referred to as contour lines. What value do these contour lines represent? Eleveation or height. Contour lines join points of equal elevation. As you see on the picture in the left hand corner there is a notation saying contour interval (C.I.) = 500’. What do you think this means? (Answer: the contour interval is the difference in value between two contour lines) Why do you think we need to establish contour intervals for our contour lines?

What is this? This is an aerial view of the island that *name* drew the contour lines on.

CONTOUR MAP This is a Contour Map. This is a two dimensional model of the islands surface. By labeling the contour lines we can see what the elevations are at various points.

There can be several answers to this. Let’s say Mt. Tim, Mt There can be several answers to this. Let’s say Mt. Tim, Mt. Tom, Woodland and Valley represent exact points on the map. Tell me the elevation at Mt. Tom? (ANS: 800’<TOM<900’) Mt. Tim? (ANS: 700’<TIM<800’) Valley? (ANS: 600’<VAL<700’) Woodland? (ANS: 600’<WOOD<700’) Why is that correct?

In groups of two or three, use this map (which is the same as the one on your hand out) and answer your hand-out questions. When you are finished please put your pens down so I know you are done.

Medial Review What is a topographic map? Why are topographic (contour) maps used? How can we label them? What do contour lines represent on topographic maps? Name a topographic structure that is represented by a contour line that closes within the limits of its map. Tell me the altitude at sea level.

Index Contour *Call on Student* Please read rule #5 on your Contour lines rule packet. Why do we only label every fifth contour line? Hint: think about the word index

Steepness *Call on Student* Please read rule #6. In your own words describe what this means? So the closer the lines, the steeper the slope?

Practice Map Draw Contour Lines

Review Can intervals between contour lines on the same map vary? Name the line that is shaded darker than the other contour lines When contour lines are close together they indicate that… What is a topographic map?

END LESSON Extra slides in case we run over. I might just have the students go around the class looking at the different topographic maps I have hung up

Contour Mapping part II Aim: What are the different features of contour maps?

How Can We Find steepness? CHANGE IN VALUE GRADIENT = CHANGE IN DISTANCE **EARTH SCIENCE REFERENCE TABLES**

Find the gradient ----- = 100 feet

Hachures

Rivers

Matching Time!