Correct Answer - Option 5 : Steep slope
Concept:
In cartography, contour lines are an imaginary line of a terrain that joins the point of equal elevation above a given level, such as mean sea level or benchmark.
Contour interval on map sheet denotes vertical distance between two successive contour lines.
Following are the characteristics of contour lines in surveying for reading contour maps:
- Two contour lines do not intersect each other except in the case of an overhanging cliff and a cave penetrating a hill.
- All lines close themselves within the map boundaries or outside it.
- If the contour lines are very close to each other, this indicates a steep slope.
- If the contour lines are at a very large distance to each other, this indicates a gentle slope.
- If the closed lines have higher elevation in the center then it represents the hill or mountain.
- If the closed line have increasing elevation as we move away, then it represents a pond or a depression in the ground profile.
- The direction of the steepest slope is along the shortest between the contours.
The contour interval depends upon the following factors:
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Scale of the Map: If the scale is small, the contour interval is kept large and vice versa so as to avoid overcrowding of contours.
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Purpose of Map: The contour interval selected should be small so that the map serves the intended purpose.
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Nature of Ground: For a flat ground the interval is kept small and for a steep slope the interval is kept large.
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Time and Funds: Contour interval is kept large when time and funds are less.
