Published: 21 Nov 2024
A career in land surveying offers a rich variety of ways the fundamental skills and methods can be applied. A land surveyor will have to undertake many different surveys and every one will be unique – each situation requires different expertise and equipment, and every location will require a different approach. The skills needed to be a surveyor are varied, so in this article we’ll look at ‘the geospatial top 10’, the 10 different types of survey they will have to carry out.
Measured building surveys
One of the core disciplines of surveying, a measured building survey involves taking measurements, which could be using digital laser scanners, to produce accurate drawings to scale. It’s a detailed record of a building or structure’s physical dimensions, its layout and features. The information can be easily shared across professions and platforms, and can be used as the starting point for design, adaptation and extension.
Topographical survey
A ‘topo’ or topographical survey is a method of mapping a landscape. This type of survey creates an extremely accurate depiction of a site, including all its natural and manmade features. It will also plot the various undulations and changes to levels across the landscape. Surveyors will use kit such as Total Stations, real-time GNSS, Terrestrial Laser Scanners and some Remote Sensing platforms such as drones, aircraft or satellites to carry out topographical surveys. The survey could be used to produce a plan so that designers know the layout of the land when planning buildings and infrastructure projects, or it could be to produce a map of an area.
UAV surveys
Unmanned Aerial Vehicle (UAV) surveys use remote-controlled drones to survey areas from height. These can be used to cover wide areas and also to survey places that are otherwise inaccessible. They can survey with efficiency, so can be useful at minimising time spent on site, and also keep costs down. Drone surveys can be carried out as a standalone project or used in conjunction with other surveys.
Boundary surveys
This type of survey defines the outer parameters of a building, other structure or land. If a building sits on a plot of land, the survey will demonstrate where the boundary of ownership reaches. It can show, for instance, where there is a party wall, with shared ownership, or how access and driveways are split or shared between properties. They are useful in settling boundary disputes or for setting out exactly where divides such as walls, fences and hedges should be sited.
Underground utility surveys
Another key survey, underground utility surveys are an essential part of the planning and construction process. Using ground penetrating radar (GPR) or Electromagnetic Location, features, obstructions and hazards that lie beneath ground level can be identified and plotted. These can include utility routes, such as electric, gas and water services, and also drainage pipework. This will enable excavations to take place quickly and mitigates against dangers such as service strikes. TSA has created a PAS128 accreditation scheme for utility surveying companies that are TSA members, named PUMA (PAS128 Utility Mapping Accreditation). The scheme, run by LRQA, aims to give clients confidence in the level of service and product accuracy assured by the accreditation.
Site setting-out
This is a vital part of the pre-construction phase of any building project, which involves ensuring the project is built accurately and in the correct place. Site engineers begin the process by overlaying the ground with ground level and sometimes subterranean floorplan and features, such as underground utility routes. The foundation layout of the structure is set out (marking where particular features need to be placed) and various aspects of the construction, such as external walls, are plotted. From below ground up, the architect or design engineer’s plans are projected onto the site and the surveyor uses specialist equipment to digitally transfer the design onto the actual site.
As-built surveys
As-builts provide an accurate representation of buildings and other structures as they stand in a point in time. They are useful to show the condition of properties, as well as the extent and dimensions. They take into account any modifications made to the structure over the years and can be used in conjunction with past drawings to note changes over time. This type of survey can also be used to demonstrate that planning regulations have been adhered to. They can provide many different aspects of a structure or building, like floor plans, or sectional and elevational views.
Deformation and movement surveys
Like As-built surveys, deformation and movement surveys can be used to monitor the changes made to buildings and structures over time. Deformation is when a structure shifts, or becomes deformed, due to external stresses and elements. A tall retaining wall, for example, could over time begin to lean and cause a danger to passers-by. A deformation survey would pick up changes to the wall and the degree and urgency with which it would need to be addressed.
Hydrographic surveys
An extension of geospatial surveying is hydrographic surveys or bathymetric surveys. This type of survey is used for inaccessible areas of open water, such as lakes, rivers, harbours, canals, reservoirs and wastewater treatment plants. It calculates the depth of the water and also measures the ground topography of the bed. It’s based on the principals of land surveying, but adapted to the conditions. Hydrographic surveys can be used for flood modelling and for planning flood prevention strategies.
Mobile mapping
Mobile mapping involves equipping a vehicle with a surveying tool – a radar or laser, for example. This mobile vehicle, which can sometimes be remotely controlled and manoeuvred, can survey large sections of road, for example, without the need for expensive traffic management having to be put in place. Using mobile mapping technology, this survey can deliver accurate data as 2D digital maps or 3D models. This method of mapping is used in producing street view pictures.
Regardless of the type of geospatial survey required, TSA members all adhere to the highest standards of professionalism and ethics. This means clients can relax in the knowledge they can feel confident in the level of service TSA members provide. Find out more about TSA membership here.
