Hill = an area of high ground generally, a smaller and rounder than a mountain, and less steep.The inside of the smallest closed circle is the hilltop. A hill is shown on a map by contour lines forming concentric circles. From a hilltop, the ground slopes down in all directions. Hills, peaks, knolls, mountains: A hill, peak, knoll or mountain is an area of high ground.Major terrain features include hills, saddles, gullies, ridges, and depressions, and they each have characteristic contour lines that make it easy to pick them out in the landscape. By comparison, a ridge is a sloping line of high ground.

“Map Reading and Land Navigation.” Washington, DC, fm: 3-25. The US Army states that “A ridgeline is a line of high ground, usually with changes in elevation along its top and low ground on all sides from which a total of 10 natural or constructed terrain features are classified”.Army, U. Bushwalkers going down the slope cannot observe most of the slope or the terrain at the bottom, so extra care must be taken when route finding.Īll terrain features are derived from a complex landmass known as a ridgeline, not to be confused with a ridge. Convex: Contour lines showing a convex slope on a map will be widely spaced at the top and closely spaced at the bottom.Bushwalkers going up the slope will find the terrain increasingly steep and challenging. Concave: Contour lines showing a concave slope on a map will be closely spaced at the top of the terrain feature and widely spaced at the bottom.contour lines may be so close that they create an impassable cliff line). Very challenging, or impossible walking (i.e. Steep: Contour lines showing a uniform, steep slope on a map will be evenly spaced, but close together.Gentle: Contour lines showing a uniform, gentle slope will be evenly spaced and wide apart.Totally flat ground has no contour lines.įour types of slopes that concern bushwalkers are gentle, steep, concave, and convex.

This slope can be determined from the map by studying the contour lines-the closer the contour lines, the steeper the slope the farther apart the contour lines, the gentler the slope. The speed at which a bushwalking group can move is affected by the slope of the ground or terrain features. The rate of rise or fall of a terrain feature is known as its slope. On 1:25,000 maps usually used by bushwalkers, contours are either 10 or 20 m apart.įor measuring between contour lines see here. The ‘contour interval’ – the elevation between contours – is the vertical distance between adjacent contour lines. Elevation and slope are the two elements that determine how landforms physically appear and connect.

Contours in geography