Some contour lines may close within the map, but others will not.
In this case, they will start at a boundary line and end at a boundary line.Contours must either close or extend from boundary to boundary
Is the topo map correct?
•Contour 1040 is very unlikely
•This would only occur if there were a long vertical wall.
1.They will meet at a vertical cliff
2.They will overlap at a cave or overhang.
3. When contour lines overlap, the lower elevation contour should be dashed for the duration of the overlap.
A series of V-shapes indicates a valley and the V’s point to higher elevation
U shapes and ridge
A series of U shapes indicates a ridge. The U shapes will point to lower elevation
Evenly spaced contours indicate an area of uniform slope.
Unevenly spaced contours indicates an area with variable slope.
A series of closed contours with increasing elevation indicates a hill.
Hills may be identified with a “+” with the elevations
Hills and Depressions--cont.
vA series of closed contours with decreasing elevation indicates a depression.
vDepressions may be identified with a “-”.
vHachures are short lines which are perpendicular to the contour line.
vUsed to indicate a hill or a depression.
vNot used on modern maps.