Topigraphic Maps

Topographic Map

A type of map that represents the locations of geographical features, using contour lines to show different elevations.

Contour Line

A line on a map that connects points of equal elevation; walking along this line means there is no change in elevation.

Contour Interval

The difference in elevation between two contour lines on a map.

Steep Slope Indication

Closely spaced contour lines indicate a steep slope, with rapid elevation changes.

Circle with Inward Hatches

On a contour map, this symbol indicates a depression.

V-shaped Contour Lines

These lines indicate stream valleys, with the point of the V pointing uphill.

Channel of a Stream

The part of the stream that carries water; indicated by blue lines on a contour map.

Scale of a Topographic Map

Indicates the horizontal distance represented on the map; essential for calculating slope.

1:24,000 Scale

A common scale where 1 inch on the map equals 2,000 feet in reality.

Shield Volcano

A volcano with broad, gentle slopes formed by low-viscosity basaltic lava.

Composite Volcano

A type of volcano that has violent eruptions due to thick, silica-rich magma.

Volcanic Hazards

Direct threats like pyroclastic flows and indirect threats such as ash fall and tsunamis.

Earthquake Wave Frequency

Refers to how the frequency of seismic waves affects building vulnerability; short buildings are affected by high-frequency waves.

Liquefaction

The process where water-saturated soil temporarily behaves like a liquid during an earthquake.

Riparian Wetlands

Wetlands located along rivers, streams, and lakes.

Depressional Wetlands

Isolated, low-lying areas not directly connected to surface water bodies.