Table of Contents
Why is it called topographic map?
Topographic maps are based on topographical surveys. Performed at large scales, these surveys are called topographical in the old sense of topography, showing a variety of elevations and landforms.
Why topographical maps are also called contour maps?
Contours are imaginary lines joining places having the same elevation above mean sea level. A map showing the landform of an area by contours is called a contour map. The method of showing relief features through contour is very useful and versatile. Henceforth, these photographs are used in topographical mapping.
Where is the name on a topographic map?
The first thing to notice on a topographical map is the title. It is found in the top right hand corner of the map (Fig. 1).
What do dotted contour lines on a map indicate?
Index lines are the thickest contour lines and are usually labeled with a number at one point along the line. This tells you the elevation above sea level. Intermediate lines are the thinner, more common, lines between the index lines. They usually don’t have a number label. Supplementary lines appear as dotted lines, indicating flatter terrain.
What are the lines on a topographic map called?
The thin brown lines snaking around a topographic map are called contour lines. All points along the same contour line are at the same elevation above sea level. Think of a contour line as a closed loop.
What is the distance between contour lines?
The distance between contour lines represents a change in elevation. Many maps are in either a 1:24 000 scale (in the US) or a 1: 25 000 scale (metric); on these maps, the contour interval is 10 feet. (This can be found along the edge of the map.)
What kind of map uses contour lines to illustrate elevation?
A map with contour lines on it is called a topographic map. Topographic maps use a combination of colors, shading and contour lines to represent changes in elevation and terrain shape. Essentially, topographic maps represent the three-dimensional landscape of Earth within the two-dimensional space of a map.