Civil Engineering Topics: Surveying Land

The detailed study of land by collecting information through observations, measurements of horizontal and vertical distances, angles, the direction of fields, research of legal instruments, and data analysis in the support of planning, designing, and establishing of property boundaries. Construction of maps, cross-sections, profiles and diagrams are represented graphically with the help of survey data.

Surveying of land is a combined work with the elements of geometry, trigonometry, physics, metrology, regression analysis, programming languages and laws. Equipment used in the surveying is total stations, theodolites, retroreflectors, GNSS receivers, 3D scanners, clinometer, radio, subsurface locators, drones, digital levels, GIS and surveying software. It is an important tool used in mapping, transport, communications, and definition of legal boundaries for the owner’s land.

Surveying can be divided into two types as follows:

  • Geodetic Surveying: The curvature of the earth is considered for the surveying of land. It involves spherical trigonometry and large distances, areas are measured. Degree of accuracy is comparatively high.
  • Plane Surveying: The surface of the earth is considered as a plane and curvature of the earth is not considered for surveying of land. This is suitable for small and flat areas and the degree of accuracy is comparatively low.

Different methods involved in the surveying are as follows:

  • Control Survey: This survey establishes horizontal and vertical positions of arbitrary points.
  • Boundary Survey: This survey determines the length and direction of landlines, and the position of these lines on the ground is established.
  • Topographic Survey: This survey gathers the data to produce a topographic map that shows the terrain configuration, location of natural and man-made objects.
  • Mining Survey: This survey is made to control, locate and map underground and surface works related to mining operations.
  • Construction Survey: This survey is made to lay out, locate and monitor public & private engineering works.
  • Hydrographic Survey: This method involves the survey of water bodies made for the purpose of navigation, water supply, or sub-aqueous construction.
  • Route Survey: This survey refers to those control, topographic and construction surveys necessary for the location and construction of highways, railroads, canals, transmission lines, and pipelines.
  • Astronomical Survey: This survey involves imaging or mapping of regions of the sky using telescopes and aerial photogrammetry.

Various topics can be studied in this subject are listed as follows:

  • Concept of surveying
  • Error and uncertainty
  • Vertical control
  • Distance and Angle measurements
  • Conventional control survey
  • Positioning
  • Earthworks
  • Underground surveying
  • Mass data methods