topography

Geographic

2022

We explain what topography is, its history, branches and importance. Also, what is topographic measurement and geodesy.

Topography graphically represents the land surface.

What is topography?

Topography is a geometric science dedicated to the graphic representation of the land surface. Is the discipline that studies the principles and procedures that allow us to illustrate the forms, details and elements of the Earth, both natural and those created by the human being.

Said representation is always made with respect to a limited area of ​​land, applying an imaginary plane and a set of three-dimensional coordinates (x, Y, z). The result is a topographic map, which indicates what the relief of the studied area.

Thus, the maps Topographic maps show the elevation of the terrain through systems of lines that connect specific points with a reference plane, which is usually sea level.

Topographic studies are very important for other disciplines, such as surveying, surveying, architecture, the archeology, the geography, caving, mapping, mining, oceanography and a huge compendium of engineering.

It is especially useful when building or carrying out civil engineering works, since basically topography deals with accurately describing the immobile physical reality of a given place, be it a town, a field or a Valley Come in moutains.

History of topography

Although there is no science Certainly an inventor of topography, it is estimated that the ancient Egyptians and the Greeks of the classical era practiced it with relish, being important builders as they were. There is evidence of the work carried out by the Pharaoh's surveyors, marking on each tilled land the portion that was destined for his majesty.

At the same time, the first to make proper geographical maps were the Greeks Thales of Miletus and Anaximander, so they could serve as initiators of the practice of graphical representation of the terrain.

The truth is that topography had its formal entry as a science from the hand of the private property, since it is an important discipline for the expansion efforts of the state and for the construction sector of public and private works. In it, it is a fairly modern science.

Types of topographic measurements

Surveying always works on the ground.

Topography work is always done on the ground, that is, always in the field of study itself. They are distinguished, however, by their methodology when making a measurement:

  • Direct measurement. Acquire your data directly, that is, comparing the real distance with the unit of measurement that describes it, such as using a tape measure, for example.
  • Indirect measurement. That which measurements are obtained by applying a mathematical formula and other forms of abstract reasoning.

Branches of the topography

Broadly speaking, the topography comprises three branches or subdivisions:

  • Surveying. Considered in many ways an autonomous discipline, it is dedicated to the measurement of distances from the Earth's surfaces, that is, measurement of areas and definition of legal limits.
  • Classic topography. It uses an abstract system of references or spherical coordinates, which can then be translated into a Cartesian axis to obtain, through calculations, the proportions of a physical space. It is divided into two, in turn:
    • Planimetry. Measurement of flat surfaces.
    • Altimetry. Height measurement.
  • Geodesy. It deals with graphically representing the surface of the Earth, understood as a macro set of surfaces, that is, from large sectorizations, which often implies sacrificing the imaginary topographic plane.

Importance of topography

Topography is indispensable in engineering and architecture projects.

Topography is essential in the measurement and representation of the world, especially for those who require a description detailed information on certain sectors of it, such as sailors, construction engineers, architects, telecommunications engineers, and a huge etcetera.

For that reason, surveyors are often involved in the early stages of virtually all construction projects. Topographic surveys are key in the planning and adaptation of the ideas in the abstract to the tangible physical space where they will be specified.

Topography and Geodesy

The fundamental difference between topography and geodesy is because geodesy has a macro focus. Globally assesses the earth's surface, serving as the basis for other geosciences and systems of information geographic.

Initially it was thought of as a branch of topography, but today it is even thought that the hierarchy between these disciplines could be the other way around, and topography would come as a kind of practical or inferior geodesy.

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