Topografia

Universidad Nacional Experimental
De los Llanos Occidentales

“Ezequiel Zamora”

UNELLEZ.

San Carlos- Edo. Cojedes











































SAN CARLOS/COJEDES

Topography



Topography (from Greek τόπος topos, "place", and γράφω graphō, "write") is a field ofplanetary science comprising the study of surface shape andfeatures of the Earth and other observable astronomical objects including planets, moons, and asteroids. It is also the description of such surface shapes and features (especially their depiction in maps). The topography of an area can also mean the surface shape and features themselves.

In a broader sense, topography is concerned with local detail in general, including not onlyrelief butalso natural and artificial features, and even local history and culture. This meaning is less common in America, where topographic maps with elevation contours have made "topography" synonymous with relief. The older sense of topography as the study of place still has currency in Europe.

Topography specifically involves the recording of relief or terrain, the three-dimensional quality of the surface,and the identification of specific landforms. This is also known asgeomorphometry. In modern usage, this involves generation of elevation data in electronic form. It is often considered to include the graphic representation of the landform on a map by a variety of techniques, including contour lines, hypsometric tints, and relief shading.Purpose


This chapter provides an overview of the types of surveys and equipment that are used for performing control and topographic surveys. It covers the various types of engineering surveys used to support facility design and construction, the different survey equipment and instruments, and the general field and office procedures that are performed.


General Definitions


“Topographicsurveying” encompasses a broad range of surveying and mapping products, ranging from aerial mapping to ground and underground surveys. “Control surveying” likewise can cover wide area geodetic surveys to construction stakeout. The following definitions from the Florida Administrative Code (FAC 2003) illustrates how topographic and control surveying falls under the overall “surveying and mapping”field:
“Surveying and Mapping: a process of direct measurement and analysis specifically designed to document the existence, the identity, the location, and the dimension or size of natural or artificial features on land or in the air, space or water for the purpose of producing accurate and reliable maps, suitable for visualization if needed, of such documentation.”

“Topographic Survey: asurvey of selected natural and artificial features of a part of theearth’s surface to determine horizontal and vertical spatial relations.”
“Control Survey: a survey which provides horizontal or vertical position data for the support or control of subordinate surveys or for mapping.”
Anderson and Mikhail 1998 define topographic surveys as follows:
“A topographic map shows, through the use ofsuitable symbols, (1) the spatial characteristics of the earth’s surface, with such features as hills and valleys, vegetation and rivers, and (2) constructed features such as buildings, roads, canals, and cultivation. The distinguishing characteristic of a topographic map, as compared with other maps, is the representation of the terrain relief.”
As outlined in the scope in Chapter 1, the guidance andinstructions in this manual will focus on the performance of site plan surveys required for the design and construction of military facilities and civil works projects. Control survey methods will focus on those surveys required to support detailed site mapping. ERDC/ITL 1999b defines installation map products as:
"Maps are tools that provide the commanders with timely, complete, and accurate...