A contour heat is a line attracted on a topographic map to suggest ground elevation or depression. A contour interval is the vertical street or distinction in elevation between contour lines. Index contours are bold or thicker currently that appear at every 5th contour line.

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If the numbers linked with certain contour lines are increasing, the elevation of the terrain is additionally increasing. If the numbers associated with the edge lines are decreasing, there is a to decrease in elevation. As a contour viewpoints a stream, canyon, or drainage area, the edge lines revolve upstream. They then cross the stream and also turn ago along the opposite financial institution of the stream creating a "v". A rounded contour indicates a flatter or broader drainage or spur. Contour lines have tendency to enclose the smallest areas on ridge tops, i beg your pardon are regularly narrow or very restricted in spatial extent. Spicy contour points indicate pointed ridges.Example 1- In the graphics below, what is the vertical distance between the contour lines?
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Pick 2 contour lines that are next to each other and also find the distinction in connected numbers.40 feet - 20 feet = 20 feetThe edge lines in this figure are equally spaced. The also spacing indicates the hill has actually a uniform slope. Native the edge map, a profile can be drawn of the terrain.Example 2- draw a profile reflecting the elevations that the contours.Note: The intervals space increasing, therefore, the contours indicate a hill. The height is normally thought about to be located at fifty percent the expression distance.
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Widely separated contour lines show a gentle slope. Contour lines that are very close together show a steep slope.
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The figure above illustrates various topographic features. (b) notice how a hill saddle, a ridge, a stream, a steep area, and also a flat area are displayed with edge lines.
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The figure over illustrates a depression and also its depiction using edge lines. Notification the mite marks pointing toward reduced elevation.

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Figure One
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Figure Two

SLOPE PERCENT from TOPOGRAPHIC MAP

The horizontal distance in between points A and also B have the right to be measured v a scaled ruler and also used to recognize the steep percent.slope percent = rise/run × 100Example 4- What is the steep percent in exercise 2 above?slope percent = rise/run × 100.For this computation, the rise, or vertical ground distance, and run, or horizontal ground distance, space needed.Step 1.Measure the horizontal map distance between points A and B to get the upright ground distance.The horizontal map distance steps 0.5 inches.Step 2.Use the ideal conversion element to convert the horizontal map distance to horizontal soil distance.0.5 in × 24,000 in/in = 12,000 inStep 3.The wanted unit is feet. Set up the cancellation table so all units will cancel, other than the desired unit, feet.

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Step 4.Use the slope percent equation and also solve. The run is 1000 feet and also the climb in key is 120 feet.slope percent = rise/run × 100slope percent = (120ft / 1000ft) × 100 = 12%Slope Worksheet- usage the information from the example over and finish the slope worksheet. Line 1 starts v the contour interval, not the projection point.Slope Worksheet (to it is in completed)

LineInput
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 ground distance, ft______
Output
SLP%SLOPE%______

Slope Worksheet (completed)

LineInput
0PPProjection pointA-B
1CON INTContour interval, ft40
2SLCMap Scale1:24,000
3CFConversion factor, ft/in2,000
4#INTVLS# of edge intervals3
5RISERise in elevation, ft120
6MDMap distance, in (between points)0.5
7HZGDHorizontal soil distance, ft1,000
Output
SLP%SLOPE%12