What are the 5 rules of a topographic map?
Topographic Map Rules
- Contour Lines Never Cross. Lines indicating elevation should never intersect on a topographic map, because each line represents a different elevation, so it is impossible to have two elevations at the same location.
- Measuring Steepness.
- Stream Flow Direction.
- Contours Close.
- Concentric Circles.
- Elevation Between Lines.
What shows a depression on a topographic map?
Contour lines that show a depression, crater, or sinkhole on a map are represented by dashed lines (hachure marks) on the inside of a contour line. The elevation of the first depression contour is the same as the nearest regular contour line.
What are the 6 rules for topographic maps?
Terms in this set (6)
- Rule 1: Slope. The closer the lines are, the steeper the slope.
- Rule 2: Flow and Source of a River/Stream.
- Rule 3: Mountains and Hills.
- Rule 4: Highest possible elevation of a hill/mountain.
- Rule 5: Depressions.
- Rule 6: Lowest possible elevation of a depression.
Can contour lines intersect?
Contour lines can never cross one another. Each line represents a separate elevation, and you can’t have two different elevations at the same point.
Why do we use contour lines?
The purpose of contour lines is to represent the tridimensional shape of the terrestrial surface on a bidimensional map. Contour lines are the intersection of an horizontal plane parallel to the reference level and the topographical surface to describe.
Can one contour line have multiple values?
Contour lines never cross. They may come very close to each other (e.g. along a cliff), but by definition they may never cross each other. * This is because one location on the surface of Earth cannot be at two different elevations!
How do contour lines show a steep slope?
Contour lines are used in a map to portray differences in elevation. When contour lines are closer together on a map, they indicate a steep slope. Think of contour lines as the distance between each incline. The closer together the inclines, the steeper the hill.
What is the difference between steep slope and gentle slope?
A gentle slope has a low slope angle and is characterized by contour lines spread widely apart whereas a steep slope has a slope angle and is characterized by closely spread contour lines.
What does a concave slope look like?
Concave Slope: The slope is very gentle at the foot and it goes on getting steeper and steeper towards the top. The spacing between successive contours at the lower level is more than at the higher level. the higher level.
How steep is a 45 degree slope?
A 45-degree pitch is equivalent to a 100-percent grade, and both mean that a run descends one vertical foot for each horizontal foot. “In perspective, a very steep highway-pass road is approximately 7 percent or about 4 degrees,” according to the Highlands Extreme Guide trail map.
How steep is a 30 slope?
Table of Common Slopes in Architecture
| Degrees | Gradient | Percent |
|---|---|---|
| 30° | 1 : 1.73 | 57.7% |
| 45° | 1 : 1 | 100% |
| 56.31° | 1: 0.67 | 150% |
| 60° | 1 : 0.6 | 173.2% |