Surveying is the profession or work of examining and recording the area and features of a piece of land to construct a map, plan, or detailed description of it. Now city surveying is one of the branches of surveying, among many others.
See also: Surveying: Your guide to the principle of surveying
City surveying: What is it?
City surveying is an extensive coordinated survey of the area within the limits of a municipality. It is an essential division of surveying as this kind of surveying involves urban land, which means workers have to deal with urban people who are not only intelligent but also educated.
So one has to be very careful in the process of conducting a proper survey of the city. One also needs to keep in mind the future development of the city and all other kinds of possibilities that the city can go through.
This is why city surveys go through two types of control, and they are as follows:
Horizontal control
First, in this control, the primary control station is established by a continuous process following one step after the other. And then there comes the formation of secondary control stations, which is also essential. These steps include a critical step, triangulation, without which any survey is incomplete.
Triangulation is the process in which the surveyors select objects which are mainly positioned at heights like water tanks, chimneys, flag poles, etc., as stations for this very step. And these objects are selected in a way so that a well-shaped triangle can be formed for the survey.
Then comes reduction, which is a process by which one can measure the angles between stations. This is because simple measurement cannot do the work. Astronomical observations are so dependent on this kind of surveying control, and so one has to take every action with extra care.
Vertical control
Just like in horizontal control, triangulation is very important, even in vertical control. Here, the main search is for the benchmarks needed to be established at convenient places all over the surveying zone. The surveyor needs to select permanent objects so that they can establish the first-order benchmarks by precise levelling on the same. Permanent objects and traverse stations are used to establish additional benchmarks when needed.
City surveying: History of surveying
Surveying is a concept that is not new and has been going on for a very long time. Land surveying, in general, was first observed in Egypt when the farm boundaries followed by the Nile River were re-established for the people to have a better way of life.
It was again used on the same land for the establishment and construction of a pyramid. But land surveying was noticed as a profession first among the Romans. And this is the knowledge by which the land in Rome was divided and became helpful as this division was used for tax collection in their empire.
Afterwards, it was spread all across the world in different countries. Surveying as a process helped people in a lot of ways, not only to mark boundaries but also to locate the very right places for the very right structures.
Lastly, it became so widespread that land survey was divided into different categories and one of which was city surveying.
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City surveying: Purposes
- First things first, one has to construct some maps that are the basic needs for the process.
- To establish a new city, one has to first take care of the roads and streets connecting the city, so it’s very much needed to lay out those new plots and streets.
- Other vital constructions that need extensive planning, such as sewers, pipelines, and buildings, also need to be mapped out.
- It is also vital to establish all the reference points and benchmarks not only for present use but also as landmarks in the future.
- Property lines need to be located by using property maps so that the boundaries are clearly mentioned, and it does not become the reason for dispute among the people of the city later.
- Topographic survey of the land is necessary for the surveyors themselves as they will be planning the whole city map, and it will also be a necessity for the people who will work for the construction of the city.
City surveying: How are maps prepared after city surveying?
One of the most important and fun parts of surveying is the formation and preparation of maps. Without maps, no surveyor can conclude the whole process of the survey. Now, as we have mentioned, it is the fun part; I also need to mention the reason for the same. Map preparation is itself an exciting process.
One needs a lot of intelligence to form a clear map to show the city’s different zones. Maps even include small parts, which are also important to mention. So if not done carefully, a map can make the whole process a lot more complex, but if one can ace the map preparation, one can carry out the whole process easier. So we need to know about map preparation more closely.
The first step when there is a huge region to cover is to divide the area into multiple maps so that each one of them gives a clear view. Let’s take a look at the different types of maps that are prepared.
Preparation of the street map
This kind of map is prepared by a plane table. In a city survey, one of the major constructions is that of roads and streets. Also, one needs to focus on the network of these roads so that the transport system can work efficiently. The name of roads, streets, and all the networks shown on the map should also be given to give a clear picture.
This map is also necessary for future use, and this is why there are fixed benchmarks in this map. Later, when more streets are needed, one can easily refer to this map. And from this map, one can come to know about the places where development is much needed so that one can carry out the process and make the city flourish.
Preparation of topographical map
The preparation of the topographical survey follows the process of transverse. A plane table, along with a tachometer, is used for contouring while making this map. While making a topographical map, the city is divided into small sectors enclosed by a polygon. Here the surveyor also ensures that one can understand the nature of the ground by giving each of them different colours and hatchings.
Preparation of the property map
The property map includes small details, and so one of the main characteristics of this map is detailing the whole zone. This map shows each bearing of the property and divides the zone into different plots. This map can also respectively show which properties are public and which are private. This can also be used when people decide as to which property they should buy.
All the properties have their boundaries and are marked very properly for the people to understand. All the plots that are shown have different kinds of land holdings and different roads or streets passing through them so that one gets the idea of which property consists of the best way for transport to different areas of the city.
Preparation of the underground map
The underground map is drawn on the same scale as the property map (1:500). This type of map is also a perfect way to know the important parts of the city. This map will show all the objects that pass through the underground. This mainly consists of telephone lines, water pipes, electric lines, gas lines, etc. In some very developed cities, there are also metro rails running in the underground area. So the map tells us about where communication could be better and where the supply of water and electricity is, and it can give us a lot of other data regarding the underground system.
The underground map can be further divided into 3 types. This is because all these individual maps are very complex, so one needs to mark them in different maps. Also, they belong to different city departments like the electricity board, the municipality, and the telecommunication department.
- The water supply and sanitary map include the whole water supply network and the sewer that passes under the ground. Some essential points of location here are inlets, manholes, purification valves, etc.
- The electrification map represents all the electric lines and their networks. These lines are shown in conventional colours to make it easier for people to read the map. And some essential locations here are the supply point, transformer location, etc.
- Telephone line maps are used to show different telephone line networks passing through different areas of the city in a way so that communication is possible from one corner to the other. Here specific symbols are used to show the crucial points in this zone.
City surveying: Instruments used for surveying
We should also know about the instruments that are used for city surveying. These instruments are necessary for a surveyor to carry out the whole process properly. Each instrument has its use and different methods of handling. Surveying needs to be taken seriously, and this is why these instruments are the investments that surveyors have to make.
Let us now list the instruments used for the surveying process:
- Ranging rods, pegs, optical squares, arrows, etc.
- Levelling instrument with tripod
- Metric chain
- Metallic tape
- Invar tape
- Transit theodolite with tripod
- Plane table instruments
- Levelling staff
Inner city surveying
Here are the top things that surveyors need to take care of while conducting an inner-city survey.
- Transport: It is one of the essential points of surveying. One needs to ensure that a city has enough transport facilities and that residents can easily travel. Surveyors need to collect data for speed traps, public transport, and football sensors that are specially stored in a GIS. So whenever going through a survey map, you need to ensure that the transport points are clearly mentioned because that shows if the city is well developed or not.
- Geo-environmental: Another important thing to know before establishing any city or town is the examination of the ground. If the ground on which the city will be built is not healthy enough, it can cause many problems for the city in the near future. A small earthquake can become the reason for the destruction of the whole place just because of a small mistake in surveying. This is why one has to know the condition of the land and also the health of the environment in that specific region to see if it is safe to build a city in that place.
- Structures: To build the structures, the engineers will need different kinds of materials. One has to ensure that the materials that will be used in the process are good in quality because they are the ones that will ensure the quality of the structures made by using those materials. So here comes another important judgement that can majorly affect the city’s people, so surveyors have to make sure it does not become the reason for any loss of life or property.
- Site engineering: Many methods, such as volume surveys and calculation and strict testing measures, are used to understand the accurate positioning of different structures. Only planning the structures won’t be enough because to establish a whole city, one has to know about the position of each building that will be built in this area. This also includes keeping healthy enough space for future use and development of the mentioned city.
- Geospatial: A prosperous city, in maximum cases, is built in plain areas. But life is changing, and so is the way of leading it. There are many cities which are getting developed in hilly and plateau areas too. But still, for each of these cases, the elevation of the land at different places should be known to the engineers so that they can build a city, keeping in mind the versatility of the elevation throughout the zone, so that all the households and commercial spaces there do not face any kind of problem afterwards.
- Monitoring: Before starting the work of building the huge city planned, the planners need to take care of the fact that there should be a distance maintained between industries and household areas. The vibrations and pollution from different areas like railways and industries respectively can cause harm to the people who are living a peaceful life in the city. It is the responsibility of the planners to ensure that the citizens of the city do not have a complaint about all these after the formation of the city so that they have to change the whole plan. So it is better to monitor before than after.
- Telecommunication: A city also needs to have things that will benefit the people living and doing business there. Communication is one such thing as everyone needs to connect with their friends, family and for work. It has become such a basic need nowadays that city planners should consider it while planning a city, at the very time of establishment and surveying. This can easily be done by the method of utility mapping.
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While the process of surveying is in motion, the surveyors need to go through a lot of processes that include electromagnetic surveying, CAD drawings, and ground penetrating radar and ensure that there would not be any problems for the people who will come and live in the city afterwards. So these surveyors should also be given enough protection because they will be doing dangerous things while covering the steps of surveying.
These surveys need to succeed because they involve a lot of money, and the failure of the project can affect the economy of the whole country, not only the city. Also, the failure may lead to different dangerous consequences, such as
- Streets losing power
- Water mains bursting
- Bus routes being disrupted
- Dangerous working conditions
City surveying: Secrets to having a successful city survey
Here are some things surveyors must do to increase the chances of a successful city survey and planning.
1) Take opinions
You need to know that taking opinions from different people can make your whole work a lot easier. You may come across suggestions that you feel are innovative, and you could have never expected such a suggestion. This can also become the turning point of your professional life so take each opinion about your planning very seriously.
2) Keep in mind the importance of the environment
We all know that the environment is what keeps us alive and healthy. So whatever the case, when making a city plan, one needs to keep in mind the importance of the environment in our life. More and more cities are needed for the increasing population to settle in, but you need to be intelligent enough to make sure that your planning does not affect the environment in the worst possible way.
Instead, you have to build a fantastic city with a fantastic environment so that the city people can have good health. This will also lead to minimum pollution, which is again an excellent point for the city and its future.
3) Take examples from other successful cities
Studying how successful cities were surveyed and planned will make it easier for you to do your own project. You can come across the mistakes they have made while planning so that you do not repeat the same. Also, you can learn from the innovative things that they did, which you can implement in your planning. This will make you a better surveyor altogether.
FAQs:
Why does city surveying cost so much?
The process of city surveying needs a lot of machines and instruments that are costly. Moreover, the work is done by experienced and highly educated professionals who do a worthy job and are paid well.
What type of survey do I need?
Now the answer to this question depends on what is the purpose of your survey. For anything related to property, the property map showing the boundary lines should be the best choice. Any problem regarding the slope will be solved by a topographical survey.
What will the surveyor provide me with after the whole process is finished?
A survey is nothing but a very well-structured plan made by professionals for making a whole establishment in the best possible way. So the surveyor should provide a pdf or file of the whole plan to you so that you can give the same to the constructor for constructing the whole thing.
Does the process take a lot of time?
Yes, surveying is a time taking process, and it involves a lot of steps that are needed to be followed. So one has to be patient while the work is done. A whole city needs to be planned without any mistakes, and the time is worth it, so the awaited result will also be amazing.