11 10 Map Reading
- 1. Map Reading Term: Topographic Map Website: http://www.uwsp.edu/geo/faculty/lemke/topographic_maps/ Or google topographic map symbols Draw the symbols for: Bench Mark – checked spot elevation Unimproved (gravel) road Depression Quarry
- 2. Topographic Map A topographic map is a detailed and accurate graphic representation of cultural and natural features on the ground.
- 3. Small-scale map (1:100,000,000) VERY LITTLE DETAIL Medium-scale map (1:250,000) MORE DETAIL Large-scale map (1:24,000) LOTS OF DETAIL Map Scale PART 1 Basic Land Navigation
- 4. What a Topo map, Aerophoto map, And actual Land features show TOPO MAP AERIAL PHOTO LAND Map Information – Identification PART 1 Basic Land Navigation
- 5. What a Topo map and actual Land features show Map Information – Identification PART 1 Basic Land Navigation
- 6. CONTOUR LINES Contour Interval ~ The contour interval is the distance between each contour line. The contour interval is found along the bottom edge, center of the map. Intermediate Contour ~ a brown line on a topographic map and represents a line of equal elevation. Index Contour ~ a bolder/wider brown line that has the elevation value marked at various intervals as a part of the line. Example: contour is 20 feet interval A =700 ft B =740 ft C =770 ft D =820 ft PART 1 Basic Land Navigation
- 7. CONTOUR LINES There is a dimension to establishing position which does depend on map reading skills. This is the vertical dimension. On a map it is referred to as “relief”. Knowledge of the relief of an area is extremely important to a wilderness navigator. The most graphic technique ever devised to show relief information is the contour line. If you were to walk a contour line you would never go down hill and never up hill, and eventually you would arrive back where you started. PART 1 Basic Land Navigation
- 8. Contour Topographic Maps use contour lines to show changes in terrain. All points on a contour line are the same ______________ All contour lines connect to _________ Two Contour lines never ________ Contour lines never split or branch
- 9. RIDGE PART 1 Basic Land Navigation
- 10. HILL PART 1 Basic Land Navigation
- 11. SADDLE PART 1 Basic Land Navigation
- 12. VALLEY PART 1 Basic Land Navigation
- 13. DEPRESSION PART 1 Basic Land Navigation
- 14. SPURS PART 1 Basic Land Navigation
- 15. DRAWS PART 1 Basic Land Navigation
- 16. CLIFF PART 1 Basic Land Navigation
- 17. What a Topo map and actual Land features show Map Information – Identification PART 1 Basic Land Navigation
- 18. PART 1 Basic Land Navigation What a Topo map and actual Land features show Map Information – Identification Compare the next five slides with this map, to get view point perspective of what you see on this map and what you see on the landscape in front of you. View 1 View 2
- 19. PART 1 Basic Land Navigation GRAND CO. BOULDER CO.
- 20. PART 1 Basic Land Navigation GRAND CO. BOULDER CO.
- 21. View 1 PART 1 Basic Land Navigation What a Topo map and actual Land features show Note: here the map is turned upside down so you can get a better perspective Map Information – Identification View 1 GRAND CO. BOULDER CO.
- 22. View 2 PART 1 Basic Land Navigation What a Topo map and actual Land features show Map Information – Identification View 2 GRAND CO. BOULDER CO.
- 23. View 1 View 2 PART 1 Basic Land Navigation GRAND CO. BOULDER CO. GRAND CO. BOULDER CO.
- 24. Map Sheets USGS topo maps Datum Declination Diagram Scale Adjoining quadrangles Few symbols Other symbols with attachment or online 7.5 minutes top to bottom & left to right
- 25. Terrain Features Hill Saddle Ridge Valley Depression – how big would it have to be to show up on the map? Draw Spur Cliff -
- 26. Grid Coordinates Start at the lower left Read to the right Read up
- 27. VGT 23
- 28. VGT 24
Editor's Notes
- #4: “ On the SMALL SCALE map all you can see is thousands of square miles of countryside, a city, and freeways, but no detail.” “ On the MEDIUM SCALE map you see more detail, the spring well and a road, but not much.” “ On the LARGE SCALE map you see the exact location of the spring well, more roads, dirt roads, trails, and a building.” Read the following ( IN BLUE ) to the students
- #5: “ Ignore the blue triangles; I couldn’t erase them from the diagrams.” * USE A POINTER GREEN CIRCLE – shows the river bend. RED CIRCLE – shows the open field. “ As you can see; the TOPO MAP show general symbols. The AERIAL PHOTO shows a 3D visual of the land. And the LAND, over time can be different (change) from both maps.” Read the following ( IN BLUE ) to the students
- #6: “ Here is another example.” Give students more detail of “what-is-what” on the picture and on the map. USE A POINTER Trees. Shrubs on very steep hill. Open, swampy field. However, on the map you see the trial and river; but on the landscape, you cannot see the trial or the river that flows into the pond. Read the following ( IN BLUE ) to the students
- #7: AT THE END OF THE SLIDE Contour Lines . The most common way of indicating elevation and relief on maps. The spacing lines indicate the nature of the slope. This has important significance to the wilderness navigator. Evenly spaced and far apart indicate a uniform gentle slope. The closer the contour lines, the steeper the terrain. Closely spaced at the top and widely spaced at the bottom indicate a concave slope. Widely spaced at top and closely at bottom indicates convex slope. Read the following ( IN BLUE ) to the students
- #8: Contour Lines. The most common way of indicating elevation and relief on maps. A line representing an imaginary line on the ground, along which all points are at the same elevation. Read the following ( IN BLUE ) to the students
- #10: Ridge . A line of high ground, with normally minor variations along its crest. The ridge is not simply a line of hills; all points of the ridge crest are higher than the ground on both sides of the ridge. Read the following ( IN BLUE ) to the students
- #11: Hill . A point or small area of high ground. Read the following ( IN BLUE ) to the students
- #12: Saddle . A dip or low point along the crest of a ridge. A saddle is not necessarily the lower ground between two hilltops; it may simply be a dip or break along an otherwise level ridge rest. Read the following ( IN BLUE ) to the students
- #13: VALLEY . A valley is a course of a stream that has at least a limited extent of reasonably level ground bordered on the sides by higher ground. The valley generally has maneuvering room within its confines. Contours indicating a valley are U-shaped and tend to parallel a major stream before crossing it. The more gradual the fall of a stream, the farther each contour parallels it. The curve of the contour crossing always points upstream. Read the following ( IN BLUE ) to the students
- #14: Depression . A low point or sinkhole, surrounded on all sides by higher ground. Read the following ( IN BLUE ) to the students
- #15: Spur . A usually short, continuously sloping line of higher ground normally jutting out of a ridge. SPURS are also called FINGERS. Read the following ( IN BLUE ) to the students
- #16: Draw . A less developed stream course in which there is essentially no level ground and therefore, has little or no maneuver room within its confines. The ground slopes upward on each side and towards the head of the draw, contours indicating a draw are 'V" shaped, with the point of the "/" toward the head of the draw. Read the following ( IN BLUE ) to the students
- #17: Cliff . A vertical, or near vertical, slope. When a slope is so steep that it cannot be shown at the contour interval, it is shown by a ticked line carrying contours. The ticks always point toward lower ground. Read the following ( IN BLUE ) to the students
- #18: “ Here is another example.” NOTE – give students more detail of “what-is-what” on the picture and on the map. * USE A POINTER Small river pond. Strip of trees and clearing. Island. Big clearing. Read the following ( IN BLUE ) to the students
- #19: “ Here you will see the same area at two different vantage points. Remember, an area in front of you looks different from behind you, after you pass it.” Read the following ( IN BLUE ) to the students
- #23: “ In the middle of the picture, in the foreground of McHenry Notch, Lake Powell is down below, in the valley.” Read the following ( IN BLUE ) to the students
- #24: “ Remember, an area in front of you looks different from behind you, after you pass it.” Read the following ( IN BLUE ) to the students