How to Use Contour Lines to Plan Your Route Effectively?

Understanding Contour Lines

Contour lines on a topographic map are imaginary lines that connect points of equal elevation. By analyzing these lines, you can identify the shape and features of the terrain, including hills, valleys, and ridges. A good rule of thumb is to consider the contour interval, which is the difference in elevation between each contour line. For example, a 20-foot contour interval means that each line represents a 20-foot increase in elevation. To plan your route effectively, look for areas with closely spaced contours, which indicate steep terrain, and avoid them if possible.

Reading Contour Patterns

When reading contour patterns, consider the following techniques:

• Identify natural ridges and valleys, which often represent the easiest routes to follow.
• Look for areas with widely spaced contours, which indicate relatively flat terrain.
• Use the “dip and rise” method to identify steep ascents and descents: if a contour line dips below adjacent lines, it indicates a descent; if it rises above adjacent lines, it indicates an ascent.
• Consider the orientation of contour lines: if they are aligned with the direction of travel, it may indicate a gentle slope or a flat area.

Planning Your Route

When planning your route, use contour lines to identify potential hazards, such as steep cliffs, ravines, and water sources. Consider the following factors:

• Avoid areas with closely spaced contours, which may indicate steep terrain or avalanche risks.
• Follow natural drainage patterns, which often indicate the easiest routes to follow.
• Use the " contour-to-contour" method to estimate the elevation gain and loss: measure the distance between two contour lines and multiply it by the contour interval to estimate the elevation change.