Supplementary contour lines are typically what style and placed where?

Supplementary contour lines are typically what style and placed where?

• A. Solid lines in steep terrain
• B. Dotted lines in areas of minimal elevation change
• C. Dashed lines at riverbanks
• D. Solid heavy lines along ridges

Answer: (B)

Contour lines show elevation, and supplementary contour lines provide extra detail where the terrain changes only slightly. They are drawn as dotted lines to distinguish them from the main contours and are placed in areas with minimal elevation change—the flat or gently sloping parts of the map. This way you can detect subtle rise or fall that the regular contour interval would miss, without cluttering steeper areas where the regular contours already convey the relief. In contrast, solid lines in steep terrain reflect the primary contour pattern where elevations change rapidly, and other styles like dashed lines at riverbanks don’t align with how supplementary contours are used.

Contour lines show elevation, and supplementary contour lines provide extra detail where the terrain changes only slightly. They are drawn as dotted lines to distinguish them from the main contours and are placed in areas with minimal elevation change—the flat or gently sloping parts of the map. This way you can detect subtle rise or fall that the regular contour interval would miss, without cluttering steeper areas where the regular contours already convey the relief. In contrast, solid lines in steep terrain reflect the primary contour pattern where elevations change rapidly, and other styles like dashed lines at riverbanks don’t align with how supplementary contours are used.