Topographic map overview

Topographic maps are a kind of general maps, which are reliable information reflecting the situation on the ground in a more comprehensive and objective way. From the map, we can understand the height and undulation of an area, the slope change, the related position of buildings, road transportation, agricultural land and water conservancy and forest and pasture, etc., and can measure the distance, area, earth and slope on the map. Therefore, topographic maps are widely used in economic construction, national defense construction and daily life.

Topographic map is in accordance with a certain scale and graphic symbols, indicating features, landforms, the plane position and elevation of the orthographic projection map. The so-called orthographic projection, that is, the projection line and the projection plane perpendicular to the intersection of the orthographic projection. Orthographic projection is also known as vertical projection, right angle projection (Figure 1-31).

Figure 1-31 Topographic Map