Topographic Definitions for Land Surveyors

topographic deflection—That part of the deflection of the plumb line which is caused by the gravitational pull exerted by topographic masses. Topographic deflection is not the same as deflection of the plumb line or station error but a theoretical effect produced by the resultant gravitational pull of the unevenly distributed topographic masses around the station, no allowance being made for isostatic compensation.

topographic feature—See topography.

topographic map—See map, topographic.

topographic survey—See survey, topographic.

topography—The features of the actual surface of the Earth considered collectively. A single feature such as a mountain or valley is referred to as “topographic feature.” Topography is subdivided into hypsography (relief features), hydrography (water and drainage features), and culture (man-made features).

topology [GIS]The geometric relationships between objects such as arcs, nodes, points, and polygons. Some topological relations include adjacency, connectivity, and containment.

Source: NSPS “Definitions of Surveying and Related Terms“, used with permission.

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