A contour heat is a line drawn on a topographic map to indicate ground key or depression. A contour interval is the vertical distance or difference in elevation between contour lines. Index contours space bold or thicker currently that show up at every fifth contour line.

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If the numbers linked with specific contour lines are increasing, the elevation of the terrain is additionally increasing. If the numbers linked with the edge lines are decreasing, over there is a to decrease in elevation. As a contour philosophies a stream, canyon, or drainage area, the contour lines rotate upstream. They climate cross the stream and turn back along the opposite bank of the stream forming a "v". A rounded contour suggests a flatter or wider drainage or spur. Contour lines often tend to enclose the smallest areas on ridge tops, i m sorry are frequently narrow or very restricted in spatial extent. Spicy contour points indicate pointed ridges.Example 1- In the graphic below, what is the upright distance in between the contour lines?
Pick two contour lines the are beside each other and find the difference in connected numbers.40 feet - 20 feet = 20 feetThe contour lines in this figure are same spaced. The even spacing shows the hill has actually a uniform slope. Native the contour map, a profile can be attracted of the terrain.Example 2- draw a profile mirroring the elevations of the contours.Note: The intervals space increasing, therefore, the contours suggest a hill. The peak is normally thought about to be situated at half the expression distance.
Widely separated contour lines suggest a tenderness slope. Contour lines the are an extremely close together indicate a steep slope.
The figure over illustrates assorted topographic features. (b) notice how a hill saddle, a ridge, a stream, a steep area, and a level area are presented with edge lines.
The figure above illustrates a depression and its representation using edge lines. Notice the mite marks pointing toward lower elevation.

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Figure One
Figure Two


The horizontal distance in between points A and also B have the right to be measured with a scaled ruler and also used to identify the steep percent.slope percent = rise/run × 100Example 4- What is the steep percent in practice 2 above?slope percent = rise/run × 100.For this computation, the rise, or vertical ground distance, and run, or horizontal ground distance, are needed.Step 1.Measure the horizontal map distance in between points A and also B to obtain the upright ground distance.The horizontal map distance actions 0.5 inches.Step 2.Use the suitable conversion aspect to transform the horizontal map distance to horizontal floor distance.0.5 in × 24,000 in/in = 12,000 inStep 3.The preferred unit is feet. Set up the cancellation table so all systems will cancel, other than the wanted unit, feet.

Step 4.Use the slope percent equation and solve. The run is 1000 feet and the rise in elevation is 120 feet.slope percent = rise/run × 100slope percent = (120ft / 1000ft) × 100 = 12%Slope Worksheet- usage the information from the example above and complete the steep worksheet. Heat 1 starts with the contour interval, no the projection point.Slope Worksheet (to be completed)

0PPProjection point______
1CON INTContour interval, ft______
2SLCMap Scale______
3CFConversion factor, ft/in______
4#INTVLS# of edge intervals______
5RISERise in elevation, ft______
6MDMap distance, in (between points)______
7HZGDHorizontal soil distance, ft______

Slope Worksheet (completed)

0PPProjection pointA-B
1CON INTContour interval, ft40
2SLCMap Scale1:24,000
3CFConversion factor, ft/in2,000
4#INTVLS# of contour intervals3
5RISERise in elevation, ft120
6MDMap distance, in (between points)0.5
7HZGDHorizontal floor distance, ft1,000