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A topographic survey is typically based upon a systematic observation and published as a map series, made up of two or more map sheets that combine to form the whole map. A topographic map series uses a common specification that includes the range of cartographic symbols employed, as well as a standard geodetic framework that defines the map ...
While not officially "topographic" maps, the national surveys of other nations share many of the same features, and so they are often called "topographic maps." Existing topographic survey maps, because of their comprehensive and encyclopedic coverage, form the basis for much derived topographic work.
The United States Geological Survey (USGS) topographical survey maps included contour representation of relief, and so maps that show relief, especially with exact representation of elevation, came to be called topographic maps (or "topo" maps) in the United States, and the usage has spread internationally.
A topographic profile or topographic cut or elevation profile is a representation of the relief of the terrain that is obtained by cutting transversely the lines of a topographic map. Each contour line can be defined as a closed line joining relief points at equal height above sea level. [ 1 ]
An Ordnance Survey cut mark in the UK Occasionally a non-vertical face, and a slightly different mark, was used. The term benchmark, bench mark, or survey benchmark originates from the chiseled horizontal marks that surveyors made in stone structures, into which an angle iron could be placed to form a "bench" for a leveling rod, thus ensuring that a leveling rod could be accurately ...
Existing conditions: Similar to a topographic survey but instead focuses more on the specific location of key features and structures as they exist at that time within the surveyed area rather than primarily focusing on the elevation, often used alongside architectural drawings and blueprints to locate or place building structures.
They are used at a variety of scales, from large-scale engineering drawings and architectural plans, through topographic maps and bathymetric charts, up to continental-scale maps. "Contour line" is the most common usage in cartography, but isobath for underwater depths on bathymetric maps and isohypse for elevations are also used.
According to the US Geological Survey, there are 5 steps to manual watershed delineation: [6] Find the point of interest along a stream on the map. This is the "watershed outlet" or "pour point." Imagine or draw surface water flow lines that point downhill perpendicular to the topographic contours (this is the steepest direction).