# blub civil
Characteristics of Contours
Must close on themselves, on or off the map.
Perpendicular to the direction of max. ...
Slope between them is assumed uniform.
The distance between them indicates the steepness of the slope, gentle or steep.
Irregular signify rough, smooth signify gradual slopes.
Concentric closed contours: hills or depression.
Rule 1 - every point of a contour line has the same elevation. Rule 2 - contour lines separate uphill from downhill. Rule 3 - contour lines do not touch or cross each other except at a cliff. Rule 4 - every 5th contour line is darker in color.
If the higher values are inside the bend or loop in the contour, it indicates a Ridge. 9. Contour lines never run into one another except in the case of a vertical cliff. In this case, several contours coincide and the horizontal equivalent becomes zero.
