Which type of contour is used to represent small changes in elevation?

Supplemental contours are designed to represent small changes in elevation on a topographic map. They provide a detailed view of terrain variations that may not be evident using index or major contours alone. These contours are typically drawn at intervals less than the standard contour interval to enhance the granularity of elevation data.

The use of supplemental contours allows for a more precise understanding of the landscape, which is particularly important in areas with gradual slopes or subtle elevation variations. Such details can be crucial for applications in engineering, environmental studies, and land use planning, where fine elevation changes can affect decisions and outcomes.

While index contours indicate major elevation changes, and primary contours, often synonymous with regular contour lines, mark standard intervals, supplemental contours fill in the gaps with increased detail. Major contours, often fewer in number, highlight more pronounced features. Thus, supplemental contours play a key role in effectively representing small shifts in elevation, enhancing the usability of the map for detailed analysis.