Topographic Maps

Index Contour

A darker, heavier contour line that is labeled with an elevation. It is usually every fifth line that indicates a change in elevation. This makes reading the map easier.

Contour lines that are far apart show what type of slope?

A gentle slope.

Contour lines that are close together show what type of slope?

A steep slope.

A map has index contours at 250m, 500m, and. 750m. What is the contour interval?

Index contours increase by 250. 250/5 = 50. 50m

How is the top of a mountain shown on a topographic map?

It is shown by a closed loop.

What color shows major roads?

Red

The highest point on a topographic map is marked as 345m. The lowest contour line is at 200m. What is the relief of the area in the map?

345m - 200m = 145m

Why can 2 contour lines never cross?

At the point where 2 contour lines would cross would have 2 different elevations which is impossible.

What color shows buildings, bridges and railroads?

Black

What color shows contour lines?

Brown

What does each contour line on a map show?

Each contour line shows a different elevation.

What color shows cities?

Gray or red.

What color shows wooded areas?

Green

What is the relationship between the relief of an area and the contour interval on a map of he area?

If the relief is high (bigger change) you will need a bigger contour interval.

Which lines are index contour lines?

In most maps, every fifth contour line is an index contour.

Contour lines

Lines or isolines on a map that connect points with the same elevation.

Features shown on topographic maps:

Mountain/Hill Depressions Streams/Rivers Escarpments/Cliffs Lakes/Ponds

Relief

The difference in elevation between the highest and lowest points in the area on the map.

Elevation

The height of an object above the surface of the sea.

Why are colors and symbols used on topographic maps?

To show information. To show different features of Earth's surface.

What shape are the contour lines that cross a valley or stream?

V shaped. the "V" points to the area of higher elevation or upstream.

What does a topographic map show?

it shows natural features such as rivers and lakes. They also show some features made by people such as brodges. They also show elevation.

What color shows bodies of water?

Blue

How can a flat map show elevations?

Contour lines are used to show elevation on a topographic map.

What is the contour interval on a map based on?

The relief in the area.

Contour lines rules:

1. Contour lines never cross. 2. All points on a contour line are at the same elevation. 3. The space between contour lines depends on the slope of the ground.

What type of relief do mountains have?

A high relief. They are usually mapped with large contour intervals.

What type of relief do plains have?

A low relief. They are usually mapped with small contour intervals.

Contour Interval

The difference between adjacent contour lines. Adjacent means next to. It is usually shown in or near the map's legend. The difference in elevation between one contour line and the next.

What is the elevation at sea level?

The elevation at sea level is zero meters.

How are depressions marked on a topographic map?

They are marked with short, straight lines inside the circle. The lines point toward the center of the depression.

How are the tops of hills, mountains or depressions (dips) shown on a topographic map?

They are shown by closed circles.

Topographic Map

shows the surface features, or topography of Earth or a certain area.