Contours and Topographic Maps Contours and Topographic Maps

Contours and Topographic Maps

Contours and Topographic Maps Types of Maps Topographic map: representation of the terrain configuration on Earth’s surface – shows detailed physical features

Contours and Topographic Maps Isolines ► Defined: Line on the map connecting points that have the same quality or intensity of a given phenomenon Ø Contour: Lines joining points of equal elevation

Contours and Topographic Maps Characteristics of Isolines ► Always closed lines ► Never touch or cross one another ► Numerical difference b/t two isolines called intervals ► Isolines close together: steep gradient (rapid change) ► Isolines far apart: gentle gradient

Contours and Topographic Maps Contour Lines Ø The changes between highest and lowest point on a map, known as relief, is indicated by the use of elevation contour lines Ø A contour line connects all points at the same elevation.

Contours and Topographic Maps Contour Lines ► The contour interval is the difference in elevation between two contour lines next to one another. ► Given a large enough map, contour lines always form an irregular circle although on a smaller map contour lines may run off the margin. ► Contour lines will never cross each other.

Contours and Topographic Maps ► Contour lines spaced closer together depict a steeper slope; and a wider spacing of contour lines depict a gentler slope.

Contours and Topographic Maps ► Contour lines form an upstream-pointing Vshaped pattern when they cross a stream.

Contours and Topographic Maps Topographic Map Ø representation of the terrain configuration on Earth’s surface – shows detailed physical features Ø Relief: change in elevation b/t highest and lowest points on map

Contours and Topographic Maps Topographic Profile ►A topographic profile is a graphic representation of graduated elevations along a line segment drawn on a topographic map. ► The topographic profile gives a side view of the landscape.

Contours and Topographic Maps Topographic Map Information ► Upper right corner: Map name, state name and 15 -minute or 7. 5 series designation ► Lower right corner: Name of the quadrant, geographic index number, and the year of the map ► Upper left corner: Primary government agency ► Lower left margin: More complete credit line and map preparation history

Contours and Topographic Maps Topographic Map Information (cont. ) ► Names of adjoining topographic maps are at each corner and along the sides of the map ► Latitude and Longitude can be found at each corner of the map ► The map scale and contour interval is shown in the lower center margin of the map