Describe the methods, procedures, and team roles in chain survey.

Team: leading chainman (leader, with 10 arrows + rod), follower (with rod), booker. Procedures: extend chain, leader takes arrows/rod, follower places rod at base point with chain handle, leader straightens chain and inserts arrow, record offsets/tie lines, then leader drags chain, follower moves to next arrow, repeat.

Topic

Elementary Survey And Map

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Meaning and Types of Survey

Simple Land Survey

Explain the meaning of simple land survey

Surveying is the science of measuring and record distances, angles and heights on the Earth’s surface to obtain data from which accurate plans and maps are made.

Surveying is also the art and science of making or taking measurements both linear and angular on the Earth’s surface at different positions for the purpose of producing a plan or map.

Angular measurementmeans measuring the distance from a given reference point to an observed object. The distance is measured in a clockwise direction from North.

Linear measurementis the distance measured along the surface of the ground such as a horizontal distance.

Purpose of surveying

To prepare maps and plans
To calculate areas and distance

Types of Simple Land Survey

Explain the types of simple land survey

Surveying can becategorisedinto various types or branches depending on its purpose, function and nature. Thetypes or branches include:

Topographical survey:This kind of survey is carried out for the purpose of preparing topographical maps.
Geodetic survey:This kind of survey is carried out with the aim of knowing the Earth’s shape and size (the Earth’s configuration)
Cadastral survey:This kind of survey is conducted with the aim of preparing a legal document such as house plans, town or city boundaries, etc. It is mainly used for ownership purposes.
Engineering surveys:This kind of survey is conducted for the building and construction layout of railways, bridges and roads.
Geological survey:This kind of survey is conducted with the aim of knowing the distribution of rocks and minerals under the Earth’s surface.
Topographical surveying:This kind of survey is carried out for the purpose of preparing topographical maps.Topographical maps are those maps whose contents include both man-made features such as linear features (roads, railways, telephone lines, water systems, and electricity poles) and natural features such as rivers, oceans, mountains, etc.The topographical survey has the following ways or methods of conducting the survey: 1.Chainortapesurvey; 2. Theprismatic compasssurvey; 3. Theplane tablesurvey; 4. The technique of levelling.

Chain Survey

Chain/Tape Survey

Methods and procedures involved in chain survey

A survey team involves three people, theleading chainmanorleader, thefollowerand thebooker.
The chain is thrown to extend it and disentangle any knots
The leader takes ten arrows and a ranging rod, and the follower takes a ranging rod
The follower erects his ranging rod/pole at the firstbase pointand places a brass handle of the chain against the ranging rod.
A leader straightens the chain and inserts an arrow at end of the brass handle. Offsets and tie lines can now be taken.
The leader drags the chain so that the follower’s end is on the leader’s arrow; the follower moves to another point and places his ranging pole behind the arrow. This procedure is then repeated.

The importance and usefulness of chain surveying

It is suitable for small areas of fairly open ground.
It is used to fill in details on a map whose large features have been surveyed by other methods.
It is used in mapping small areas of flat or near-flat ground and associated objects, for example paths, roads and railways.
It is used in adding detail to existing plans or large maps.

Advantages of chain surveying

It is the simplest method of surveying through the old method.
It is suitable for surveying clear areas.
It tends not to attract attention.
It is suitable for surveying a flat surface on the Earth’s surface, for example a school compound.
It can be read easily and quickly.
It can withstand wear and tear.
It can be easily repaired or rectified in the field.

Disadvantages of chain survey

It is a slow method of surveying.
It is the oldest method of surveying
It is not suitable for surveying large areas.
More difficult areas cannot be chain surveyed.
Errors may be encountered due to the use of many chains and other reasons.
It is time consuming.
They are heavy and take too much time to open or fold.
They become longer or shorter due to continuous use.
When the measurement is taken in suspension, the chain sags excessively

The Importance of Survey

Explain the importance of survey

Importance of surveying

It help to prepare a topographical map which shows the hills, valleys, rivers, villages, towns, forests, etc. of a country.
It helps to prepare a cadastral map showing the boundaries of the fields, houses and other properties.
It help to prepare an engineering map which shows the details of engineering works such as roads, railways, reservoirs, irrigation canals, etc.
It help to prepare a military map showing the road and railway communications with different parts of a country.
It helps to prepare a contour map to determine the capacity of a reservoir and to find the best possible route for roads, railways, etc.
It helps to prepare a geological map showing areas including underground resources.
It helps to prepare an archaeological map including places ancient relics exist.

Elementary Survey And Map – Form Three Geography

Test your knowledge on the meaning of simple land survey, types of surveys, chain survey methods, equipment, procedures, and the importance of surveying. Read each question, consider your response, then click the panel to reveal the detailed answer based on the official syllabus.