Definition of Contour Interval

The vertical difference between any two consecutive contours is remembered because the contour interval. as an example , if the various consecutive contours are 100 m, 98 m, 96 m, etc., then the contour interval is 2m.interval depends upon, the character of the bottom , the size of the map, and therefore the objective of the survey. Contour intervals for the flat country are normally small, e.g. 0.25 m, 0.5 m, 0.75 m, etc. For a steep slope during a hilly area is considerable,
e.g. 5 m, 10 m, 15 m, etc.
Similarly, for a small-scale map, the interval could also be 1 m, 2 m, 3 m, etc. and for a large-scale map, it's going to be 0.25 m, 0.50 m, 0.75 m, etc. It should be known that the contour interval for a selected map is constant.

What Is Contour Interval?

The Contour Interval is defined because the vertical difference or distance in elevation between the contour lines. Index contours are thicker or bold lines that reach every fifth contour.
If the numbers connected within particular contour lines are rising, the elevation of the terrain is additionally rising. If the numbers connected with the contour lines are decreasing, there's a discount in elevation.
For the plotting of the region, the contour intervals are considered, the contour intervals are indicated on the right-hand side. When the contour interval isn't indicated within the map, it's going to be computed within the subsequent sections, the mainly utilized contour interval is 20 feet for a 1: 24,000 map scale.

How To Calculate Contour Interval On Maps.

A map legend usually specifies the contour interval on the map, but sometimes just some of a map is out there . Understanding the way to compute the contour interval becomes a valuable skill.
On most of the maps, each fifth contour , indicated as a heavier or darker line, is an index line or index contour.

How to Find Contour Interval

The calculation of the contour interval,

1. Considering the above map for the calculation of intervals, the steps involved in contour interval computation.
2. Let’s assume two index contour lines, 7000 and 7100, and compute the interval between them.
3. The difference between the 2 selected index contour 7100 and 7000 is 7100 – 7000 = 100
4. Now count the amount of non-index lines contour lines between 7000 and 7100 is 4.
5. The number of lines acquired within the above step is 4 and added with 1.
6. Adding, 4 + 1 = 5
7. Now divide 100 by 5, 100/5 = 20 units.