How can you use the rule of V’s to determine the flow of a river? All water flows downhill, from areas of high elevation towards areas of lower elevation. The bending of the contour lines near the river always points uphill, which means RIVERS ALWAYS FLOW IN THE OPPOSITE DIRECTION FROM THE WAY THE CONTOUR LINES BEND.

Widely spaced contour lines indicate that the land is relatively level. A contour line that bends to form a V shape indicates a valley. The bend in the V points toward the higher end of the valley; this V points upstream, or in the direction from which the water flows, if there is a stream.

If there is a low place such as a sinkhole, a crater, or another enclosed area of low elevation, it is called a depression. The hachure marks point downslope toward the center of the depression. The image to the right shows how a depression would be represented on a map.

Contour lines can never cross one another. Each line represents a separate elevation, and you can’t have two different elevations at the same point. The closer contour lines are to one another, the steeper the slope is in the real world.

A depression is represented by a series of concentric closed contours with the inner contours having lower elevation than their outer surrounding. There are small tick marks or hachures on these contour lines pointing towards lower elevation.

Contour lines never cross on a topographic map because each line represents the same elevation level of the land.

These contour lines are an important way of showing the rise and fall of the land on a map. Contour lines show all the places that are the same height above sea level. They also tell us about the slope of the land. On a steep slope, the lines are close together.

The contour lines mark where the land surface is one inch higher than the previous contour line. If the land surface is steep, the contour lines will be closer together. If the land surface is gently sloping, the contour lines will be farther apart.

Contour lines that are further apart indicates a slope that is relatively flat. The area of the map above boxed in orange shows an area that has a fairly steep slope, while the area boxed in purple is a relatively flat area. Contour lines on the map also show how water will travel across the land.

A contour interval is the vertical distance or difference in elevation between contour lines. Index contours are bold or thicker lines that appear at every fifth contour line. If the numbers associated with specific contour lines are increasing, the elevation of the terrain is also increasing.

Divide the difference in elevation between the index lines by the number of contour lines from one index line to the next. In the example above, the distance 200 is divided by the number of lines, 5. The contour interval is equal to 200 / 5 = 40, or 40-unit contour intervals.

: the vertical distance between the elevations represented by adjacent contour lines on a map.

In cartography, a contour line (often just called a “contour”) joins points of equal elevation (height) above a given level, such as mean sea level. A contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

1 Answer. If contour lines are close together, it is a very steep slope; if they are far apart, it is a gradual slope.

Objectives. An objective of topography is to determine the position of any feature or more generally any point in terms of both a horizontal coordinate system such as latitude, longitude, and altitude. Identifying (naming) features, and recognizing typical landform patterns are also part of the field.

Contours make it possible to show the height and shape of mountains, the depths of the ocean bottom, and the steepness of slopes. USGS topographic maps also show many other kinds of geographic features including roads, railroads, rivers, streams, lakes, boundaries, place or feature names, mountains, and much more.