it is a contour line of elevation Control index contour, or just index contour
create a sentence for contour line
The main topographic map rules include contour lines never crossing, contour lines close together represent steep terrain, contour lines spread out represent flat terrain, and elevation is indicated by the contour lines.
A contour line is a line defining elevation on a map.
A contour line in art is an outline of a subject with no shading.
Contour interval
It makes it easier to count the number of contour lines.
lower.
An Index Contour
An index contour is a thicker contour line that is labeled with the elevation of that contour. It usually appears every fifth contour line and helps to quickly identify elevation changes on a topographic map. Regular contour lines are thinner and connect points of equal elevation.
When a V-shaped contour line points downhill, it means that the contour line is under very low elevation. And incase your wondering about when the contour line is uphill, it means that the elevation level is very high.
The first contour line was created by Charles Hutton in 1771. He used contour lines to map a coal mine.