What are they? Why are they useful? How do you read one? Topographical Maps What are they? Why are they useful? How do you read one? Thumbs up if you know how to read a topo map Thumbs middle if you know what a topo map is but not how to use one Thumbs down if you’ve never heard of topographical maps

Topography Refers to the human and physical surface features of an area Topo maps have contour lines that show elevation Sometimes called “contour maps”

Rules for Reading and Creating Mean sea level is an elevation of 0 feet Every point on a contour line has the same elevation above sea level Always check the map for the contour interval in use What is our elevation here? Elevation at the bottom of the canyon? Talk to neighbor about question (interval is 50ft) What is the contour interval for this map?

Rules for Reading and Creating Contour lines never cross one another Contour lines are closed figures Small, closed loops indicate hilltops Ridges are hills that are long and narrow

Rules for Reading and Creating Spacing of contours depicts slope Relief is variation in elevation and slope

Rules for Reading and Creating Where streams are shown on a map, the contours always form a V or a U shape with the apex pointing upstream (higher)

Rules for Reading and Creating Hatchure lines represent a depression. They point in to the lower elevation.

Rules for Reading and Creating Benchmarks are exact elevations … and by a brass plate on the ground Marked by an X on the map…. Elevations indicated precisely are spot elevations or benchmarks. Spot elevations have been checked by surveyors..

Slope Hill Valley Ridge Depression Saddle What are these features? Slope (Brown) The steeper the slope, the closer the contours, because it takes less distance to rise or fall a given amount on a steep slope. Hill (Yellow) Contours are concentric with maximum elevations in the center Valley (Blue) Lower elevations in the center. Contours form V's that point upstream. Ridge (Green) An elongate hill. Elevations high in the center. Contours form V's pointing downhill. Depression (Red) Uncommon, and usually shown with hachured contours. The hachures are on the downhill side. Saddle (Purple) The landform that confuses more beginners than any other. Land slopes downhill in some directions, uphill in others. Any time you have four elevation points, with the points on one diagonal high and the other low, you probably have a saddle.

Draw its profile

Draw its profile