What is Topographical Survey? Types of Topographical Survey
What is Topographical Survey
A Topographical Survey is an accurate picture of a site (property, area of land, specified boundary) that is scaled and detailed based on spatial considerations and is a summary of the on-site data-collecting operations.
The goal is to collect spatial information about the place (natural and man-made land features). This is frequently linked to the national Ordnance Survey grid and datum information (sometimes via GPS) and is surveyed point by point.
It is commonly agreed that points are positioned in three dimensions, which helps the production of ground modeling and visualizations from the topographical survey.
History of Topographical Survey
Detailed military surveys in Britain (starting in the late eighteenth century) were known as Ordnance Surveys, and this phrase was used as a general term for topographic surveys and maps into the twentieth century.
In France, the first scientific surveys were known as Cassini maps, after the family that created them over four generations. The phrase “topographic surveys” appears to have originated in the United States.
The “Topographical Bureau of the Army,” created during the War of 1812, which became the Corps of Topographical Engineers in 1838, produced the first thorough surveys in the United States.
After the United States Geological Survey took over the job of national mapping in 1878, the word topographical persisted as a general term for thorough surveys and mapping projects and has been accepted as standard by most other nations.
Types of Topographical Survey
The different types of Topographical Survey are:
- Mortgage Survey- This usually involves a land and property survey done by using a permanent method of measuring. This type of survey is useful as this helps in future planning and assesses the value of properties.
- Building Survey- People usually build their homes during the land surveying period, which involves lot measurement and property assessment to determine the amount of money that should be spent for the build, constructions, and maintenance procedures for several years to come.
- Hydrographic Survey- Land surveyors are also responsible for completing hydrographic and bathymetric surveys, which may seem counterintuitive.
Hydrographic surveys collect data on any body of water, including water depth, bottom contours, current direction, detecting and documenting high watermarks and water levels, and the location of permanent objects and landmarks for navigational purposes
They can also be used to collect data for technical or resource management applications, such as hydropower plants. Bathymetric surveys are conducted entirely underwater to determine the seafloor profile.
- Wetland delineation- Delineation and Location of Wetlands Surveys are a separate category; They are carried out when building activity is proposed on or near a location with designated wetlands.
Wetlands are often defined as places that are entirely submerged in water for more than two weeks throughout the growing season, according to local, state, or federal standards.
Wetland boundaries are defined by studying the land’s soil colors, vegetation, erosion patterns or scour marks, hydrology, and morphology.
Data on the positions of the planted flags is then collected, and a map is made to reference the wetlands’ limit and compare it to the projected boundaries of the surrounding plots or parcels of land, as well as the development activities proposed therein.
- Geodetic Survey-Geodetic Surveys are classified as both land and sea since they map the coastline. In 1807, Thomas Jefferson commissioned the Survey of the Coast, a geodetic survey. Progress on the survey was slow at initially since they did not have the necessary tools until 1815.
It still exists today as the National Geodetic Survey, and its responsibilities now encompass both the interior and the coastlines of the United States.
Purpose of Topographical Survey
Topographical survey has different purposes. They include:
- Real Estate Appraisal- It is a service provided by the land surveyors to anyone interested in buying a land that needs an appraisal for the property’s value.
Topographical Survey is commonly used to determine land value because it is precise and accurate.
- Research of Land Usage and Management- Topographical survey provides useful information regarding the zones where there are no trees, which are prone to erosion, flooding and in developing countries, this data can be used for informing people on which places need reforestation programs.
- Land Management Optimization- Topographical Survey can be used to optimize land management practices.
- Topographic Modeling- Topographic models can be used for checking the performance and safety of building sites, roads, and bridges as they are built and maintained.
Topographic models are used to check the landscape-to-structure interface.
- Property line survey for civil engineering design- Topographical survey is commonly used in civil engineering to define property lines and other limiting boundaries of construction projects so that the owners do not build structures that may potentially damage buildings or facilities nearby.
It is important for the surveyor to be able to provide an accurate description of all things within a given boundary of a parcel, including easements and existing improvements on neighboring parcels.
- Risk Management- Topographic data can be used to inform the public about areas prone to flooding, landslides and other loss events.
- Parcel Determination- Topographic data is also useful in establishing parcel boundaries, which is helpful for assessing land ownership and also for determining legal boundaries of all types.
- Stock Assessment- Topographical survey is also used to inventory stock and animal populations in areas of known concern.
- Bridge design and construction-Topographic data is useful for determining the depth of piers and other necessary structures for bridge design and construction.
- Landscape Design-Topography is useful information for designing landscapes with changes in elevation, topography, drainage, slope, the distance between features, and many other elements.
Benefits of Topographical Survey
The benefits of Topographical Survey are:
- Improves land management strategies- Topographical Survey helps in improving land management strategies.
- Reduces environmental risks- Topographical Survey provides valuable information on the location of major environmental hazards.
- Saves money and resources- Topographical survey is a fast, simple and easy way of determining the area in which there is a property owner or businesses do not need to spend money or energy on landscaping, topography or other improvements to the surrounding area.
- Protects assets- Topographical Survey is used to protect assets like bridges, buildings, and other public or private facilities that are located in areas of natural concern.
- Makes land-use decisions more precise- Topographical Survey can help improve the decision-making process by providing detailed and accurate information to the landowners, developers, and builders.
- Provides accurate data for environmental protection- Topographical survey is also used to provide accurate data for environmental protection, especially when carrying out biophysical or social research studies in various regions of the world.
Limitations of the Topographical Survey
The major limitations of Topographical Survey are;
- Dependent on surface conditions- The data obtained from the topographic survey is dependent on the surface features as well as other environmental conditions.
- Intercepting underground utilities- Topographic survey often encounters problems with utilities that are underground and not visible above ground, which can make it difficult to determine where boundaries lie in these cases.
- Dead-ends- The topographic survey is limited by where it can be conducted and how accurate it can be in determining the boundaries of a certain parcel.
- Difficulties in determining length and width of the survey area- Topographical survey is typically limited because of the length and width at which it is conducted, especially if there are large areas that need to be covered.
- Riparian areas- Topographical Survey has problems delineating riparian areas because they are often poorly defined or not visible above ground.
- Subject to human error- Topographical survey is subject to human error and can be incorrect if the surveyors make mistakes while conducting the survey.
- Longer surveys- Surveying large areas can take up a lot of time and be very expensive, limiting the ability of a surveyor to conduct accurate surveys over large areas.
- Accuracy- Topographical survey is often not accurate, especially on smaller and more remote areas.
- Limited utility- Topographical Surveys have limited utility for land management and land use planning because of the size of the area covered and the accuracy of data provided.
- Not all properties are eligible- The majority of properties are not eligible to be surveyed since they are either too large or too small in comparison to other properties that can be surveyed.
Methods of Topographical Survey
The most common method of conducting a topographical survey is the field survey, which may be conducted in either the field or in a laboratory, depending on the situation. A field survey was conducted by William Cairnes in 1914.
Passive Sensors Methodologies
This is another method of conducting a topographical survey is using a passive sensors methodology, which can be conducted using either gravity or magnetic sensors.
This is another method of conducting a topographical survey is by using GPS technology.
This type of technology was first developed in 1973 and since then it has been used to provide more accurate results than traditional methods of surveying.
Active Sensor Methodologies
This is a method of conducting a topographical survey is via active sensors, which is a term used to describe any type of technology that the surveyor actually interacts with while conducting his or her survey.
This is a method of surveying that combines the use of ground or airborne surveys, or both in order to improve the results of the survey.
This is a survey method that uses the analysis of data that has been gathered from various sources, such as satellite data or aerial photography.
Topographic Survey Process
The following is a list of the steps that are typically included in any topographic survey:
- Bearing and elevation measurements- The values of bearing and elevation that are obtained using a total station are used to calculate angles and Kinematic Elevation Meter (KEM) values.
- Boring to avoid obstacles- An accurate survey is required before boring can begin so it is necessary to take measurements and avoid obstacles to better ensure that the coordinates provided will be accurate once boring has finished.
- Horizontal and vertical coordinates- Coordinates are determined using the total station and data is collected to ensure that they are taken correctly.
- Making adjustments- Adjustments are made to the survey figures so that they fit into the designated area and help to ensure that there are no errors when collecting information on the land owner’s property.
- Events recording- Events recording is used to record any event that may affect the accuracy of the topographical survey, such as any changes in ground level or any obstructions that could affect either the total station or GPS coordinates.
- Reconstructing the data- Reconstructing the data is used to convert the data into property descriptions, which is needed to determine where the boundaries are of a certain property.
- Making adjustments- Adjustments are made after converting the data into property descriptions to ensure that there is no human error, which could cause problems with accuracy in terms of measurements and coordinates.
- Reporting- Topographical surveys are typically completed by a land surveyor and have to be verified and submitted by the surveyor to a level-one entity, depending on the kind of documentation that is required.
- Drawing of final map- Once the survey is complete, a topographical map must be drawn up to show all of the survey data in a clear and concise way so that it can be interpreted easily by other surveyors and stakeholders.
- Stakeout- The final map must be staked out to ensure that the data has been accurately mapped and recorded.
- Recording of results- The results of the survey are recorded by documenting all information about the survey such as where it was conducted, when it was conducted and by whom.
- Registration- Once the results have been recorded, they are then submitted to a land registry or land administration.
- Publication of survey results- Survey results are then published in a number of different ways, including the use of maps and the recording of survey data in an official record or legal document.
- Analysis- The map that is created is analyzed by a qualified surveyor who will make corrections to it based on any concerns that may be present as well as conduct another survey if necessary.
- Relocation- Last, but not least, the original map or survey data must be relocated for the original survey to be accurate. This can be done by placing stakes in areas that were incorrectly measured and then recalculating the map from there.
- Presentation of Survey Data- Once all of the corrections have been made, a topographical survey must be done again to show any discrepancies present in information before it can become an official record at the land registry or other official agency.
- Registry or Land Administration- If the survey is done by a private land surveyor, the results are then submitted to a registry or land administration for their records.
- Validation of Surveyor’s Accuracy- Last, but not least, it is necessary to have the surveyor and all of his associates meet certain qualifications in order to validate their accuracy of the information they have provided.
How accurate is topographical surveying?
It is possible to achieve an accuracy level of 0.1-0.5 meters for topographical surveys depending on the equipment used for the survey, the type of terrain that is being surveyed, and quality control measures implemented by the surveyor or supervising organization.
How are topographical maps created?
Topographical maps are created from a series of topographical surveys which together represent different aspects of a location or region (wide area topographic mapping).
How long does it take to survey an area?
It depends on the size of the area being surveyed and the equipment used for it. The time required for a topographical survey is between 4 days and 2 weeks for an area measuring about 10 hectares.
How much does a topographic survey cost?
The cost of a topographic survey varies from $5 to $10 per square meter depending on the equipment used, the size of the area that is being surveyed, quality control measures implemented, and whether or not drones are used to carry out aerial photography of an area.
Is topographical surveying necessary for land development or management planning?
No, topographical surveys are not necessary for land development or management planning but they are often required in order to accurately record ownership of a piece of property.
The only time that it might be necessary to conduct a topographical survey is when you have reason to believe that there may be an existing claim or entry on the land.
What are the advantages of conducting Topographical survey?
The main advantage of conducting topographical surveys is the ability to provide a new perspective on an area that helps develop an understanding of the features present in it.
What are the disadvantages of conducting a Topographical Survey?
The main disadvantage to surveying an area using traditional methods is that it can take over 6 months and cost between $10,000 and $15,000 to complete a survey.
The money that is involved can be better spent elsewhere or used for another project if the next option is chosen in the list above.
What is the difference between topographical surveys and boundary surveys?
To put it simply, the difference lies in the types of surveying equipment used for either of these two surveys. A boundary survey involves a series of measurements made at least every 15 meters while a topographical survey requires measurements be made at least every 10 meters.
What is the difference between land surveying and topographical surveying?
To put it simply, land surveying involves the measurement of contours while topographical surveying involves the measurement of approximately 10 points per square meter.
What are some of the most common types of errors that are associated with topographical surveys?
There are a number of common errors that occur in topographical surveys including poor data collection, poor record-keeping, and poor interpretation of data.
What type of equipment is required for conducting a topographical survey?
There are a number of different types of equipment that can be used for topographical surveying depending on the area being surveyed and the type of terrain that is being examined.
Here is a quick reference when it comes to the types of equipment:
- GPS units- GPS units are used to provide precise location coordinates as well as record locations and times.
- Cameras- Digital cameras and video cameras can be used to produce panoramic images, orthomosaics, photographs and time lapse sequences.
- Stakes and strings- Stakes and strings are used to show accuracy of the measurements taken.
- Distance meters- These are a type of instrument that helps to determine the amount of time that it takes a person to travel or run certain distances.
What is included in a Topographical Survey?
A topographic survey locates and illustrates all-natural features and elevations on a property’s surface.
It is essentially a three-dimensional map of a three-dimensional property that depicts all-natural and man-made features and enhancements. It specifically displays their position, size, height, and any elevation variations.