What is topography?

What Does Topography Mean

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

The topography graphically represents the land surface.

What is topography?

Topography is a geometric science dedicated to the graphic representation of the earth's surface . It 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 humans .

This 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 the relief of the studied area.

Thus, the maps topographic elevation show the ground through systems of lines connecting specific points with a reference plane, which is usually the level of the sea.

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

It is especially useful when building or doing civil engineering works, since basically topography deals with accurately describing the immobile physical reality of a given place, be it a city , a field or a valley between mountains .

It can help you: Physical geography

History of topography

Although there is a science true inventor of the topography, it is estimated that the ancient Egyptians and Greeks of the classical era practiced it with relish, being as they were important builders. There is evidence of the work carried out by the Pharaoh's surveyors, marking in each cultivated 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 entrance as a science from the hand of private property , since it is an important discipline for the expansion efforts of the States 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.

Surveying tasks are always done in the field, 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, by 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 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. The measurement of heights.
  • 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 detailed description of certain sectors of the world, such as navigators, construction engineers, architects, telecommunications engineers, and a huge etcetera.

For that reason, surveyors are often involved in the initial stages of virtually all construction projects . Topographic surveys are key in the planning and adaptation of 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 land surface, serving as the basis for other geosciences and geographic information systems.

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 be a kind of practical or inferior geodesy.

Continue with: Geophysics

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