Topographic Maps

What kind of maps have we dealt with so far?

2D Maps North, South, East, West, Etc Sort of like an X and Y Axis on a Cartesian Plane

How Can We See Elevation on a 2D Map? Mountains Hills Cliffs Etc.

Topographic Maps! We are still looking at a map as if we are looking at the earth from Space! Ie. Top Down However, with these maps, we use special LINES to determine Elevation!

Some Terminology Elevation: The height above sea level. Sea level is at ZERO ( 0 mm, cm, m, km) Topographic Map: A very detailed map of a physical or human feature that shows DEPTH/ ELEVATION and the SHAPE of landforms Contour Lines: Lines on a map that connect points with the SAME Elevation

Let’s Take a Look On this map, we want to find 1. The Contour Interval 2. Where is the TOP of the Mountain? 3. Where is the BOTTOM of the Mountain? 4. Which parts of the Mountain are STEEPEST and LEAST STEEPEST? 5. What might the mountain look like in real life?

Height in Metres (m)

What did we find? Contour Interval: 20m Steepest Section: Between 820 and 840 m on the West side of the Mountain. Least Steep Section: Between 760 and 780 m on the East and West sides of the Mountain Rings of circles that get smaller and smaller always represent mountains or hills

Top? What does it look like (South side)?

What did we Learn? Contour Interval: The distance in Elevation (Height) between each Contour Line. The Mountain is Steepest (Cliff) when the lines are CLOSEST together The Mountain is Least Steep (Gentler) when the lines are FURTHEST apart. It’s impossible to know EXACTLY what a mountain looks like from a Topographic map, bit we can get a GOOD IDEA!

Determining Contour Interval What is the Contour Interval for this Topographic Map?

What Did We Find? What’s shown is 400 m and 500 m We count 5 contour lines to get from 400m to 500m The difference between 500 and 400 is 100 100 divided by 5 = 20 Contour Interval = 20m

When Mountains Cross Rivers

Rivers When Contour lines cross rivers, they form a V – Shape The Bottom of the V is where the water is coming From Label the Direction of Water Flow, the Source, and the Mouth of the river

Mouth Source

Getting More Specific with Height! Hint: The peak lf this mountain (tallest point) is not Actually 320 m!

We Can’t Tell the EXACT HEIGHT So it’s a Range Must be Higher than the PREVIOUS contour Line But not higher than what the Next Contour Line would be! Previous Contour Line: 320 m Next Contour Line: 340 m What’s the Mountain Peak? Mountain Peak: 321m to 339m

What’s the Opposite of Up? Regular straight Contour lines mean that the elevation is going UP Hashed/Hachured Lines mean that the elevation is going DOWN

What Might This Mountain Be?

Cross-Section Graph We can turn a Topographic map into a Cross-Section Graph This is the same as cutting a mountain in half, and viewing from the side like in real life

The Video https://www.youtube.com/watch?v=c7gT8gU_pD8

Summarized 1. Take a piece of paper, and place it horizontally across the Topographic Map as seen in the Video 2. Mark the Contour lines from the Map on your piece of paper (This is your X Axis) 3. Create your Y Axis, by marking all of heights from Least to Greatest, but this time, EVENLY spread out 4. Match up the Elevations on each Axis with a dot, and then connect them with a line

Remember Topographic Maps are viewed TOP DOWN (Like from Outer Space) Cross-Section Graphs Are viewed STRAIGHT ON from one direction, as if you are viewing the mountain cut in half