GEOMATICS AND LAND SURVEYING
PRACTICE OF THE LAND SURVEYORS
The work of the land surveyor is very varied and his practice may fall under one or more of various categories, such as cadastral surveying or surveying for title, engineering surveying, topographical surveying, photogrammetry, geodetic surveying and hydrographic surveying. Except for geodetic surveying and photogrammetry, the other categories in land surveying involve essentially large-scale surveys.
CADASTRAL SURVEYING OR SURVEYING FOR TITLE
Cadastral surveys or surveys for title are made to establish and record property boundaries and may form the bulk of a land surveyor’s work. Cadastral surveys are controlled by law and in accordance with the provisions of the Land Surveyors’ Act, St. Lucia, No. 13 of 1984. Those permitted to do cadastral surveying field-work are, firstly, the employees of the Survey Department working under the supervision of the Chief Surveyor, and, secondly, the articled pupils and fields assistants working under the immediate personal direction and field supervision of surveyors licensed under the Land Surveyors’ Act 1984.
The Survey Department imposes stringent regulations on cadastral surveying. Such regulations and the categories of persons permitted to do cadastral surveying, reflect the importance attached to the cadastral plan, the usual end product of a cadastral survey. The plan should unambiguously identify a particular parcel of land for purposes of proprietorship and registration, and the survey should be of technical standards required in the legislation governing the registration of title to land and of dealings herewith.
The Land Surveyors’ Act 1984 provides for the establishment of the Land Surveyors Board, to deal with “the licensing and control of land surveyors and for matters connected therewith.”
In this connection, it should to be mentioned that the Land Surveyors’ Act, 1984, is largely outdated. It was promulgated to meet a situation that existed almost thirty years ago.
To dispel any possible misconception, it is stated here that engineering surveying is still land surveying, done specifically for engineering purposes. Engineering surveying is ultimately tied to cadastral surveying, because an engineering survey is hardly ever done in isolation. It must be properly orientated and must be tied to the survey marks authorised by the Survey Department, such as boundary marks, triangulation points whether primary, secondary or tertiary. The licensed surveyor is thus the proper person to undertake an engineering survey, because by law, he is authorised to undertake a cadastral survey.
Large scale and engineering surveys form a very important part of a licensed surveyor’s practice, because surveying is fundamental to any project planning. Licensed surveyors are thus appointed by various Government technical departments and statutory bodies to carry out engineering surveys, with the object of providing large-scale plans and profiles, showing topographical detail and additional information, necessary for the design and planning of engineering projects.
Unlike cadastral surveying, there is no statutory control over the conduct of engineering or topographical surveys. However, it should be remembered that the Malaysian land administration system, which make tenure secure and title readily transferable, subject to certain controls, has the cadastral plan and the land register as its twin pillars of its machinery of record.
Topographical surveys are made to establish the positions and shapes of natural and artificial features in a given area for the purpose of producing a topographical plan or map.
The relative positions and heights above mean sea level of the control points, forming the network, have to be established in order to provide the horizontal and vertical control for the subsequent survey of topographical detail.
The traditional base-line measurement and triangulation network to establish the horizontal control, has been largely replaced by trilateration, because distances of up to more than 100 kilometres can be rapidly measured by electronic distance-measuring equipment. The vertical control is established by levelling or trigonometrical heightening, which is usually referred to as mean sea level datum.
Topographical surveying for the country is the responsibility of the Department of Survey and Mapping but detailed topographical plans of relatively small areas are required by various Government departments and statutory bodies for project planning and design. Such topographical surveys are undertaken by licensed surveyors. A word of caution may perhaps be necessary here. Clients resorting to the easy way out by blowing up small maps, suitable for feasibility studies, for large scale survey information, can expect to find trouble in the design and planning phase of the project.
The traditional ground survey for picking up topographical detail has been very largely replaced by mapping from air photographs. The area to be mapped is covered by strips of overlapping air photographs which show control points already established on the ground. With the aid of photogrammetric plotting equipment, a pair of overlapping photographs provides the operator with a three-dimensional ‘model’ of the ground, for plotting the topographical detail.
Since mapping is the responsibility of the national mapping organization and with the very stringent restrictions on the sale of topographical maps in this country (for security reasons), there seems to be less scope for photogrammetry in the private sector. However, to satisfy the increasing pace and demands of development and with the advancement in photogrammetric technology there is now an emerging market for photogrammetry in the private sector.
To avoid the accumulation of errors, extensive surveys should proceed from the whole to the part, by first establishing a network of primary triangulation points. The primary triangulation is broken into secondary triangulation, which is again further broken into tertiary triangulation. These triangulation networks are supplemented by precise traverses until there is a sufficient density of control points for the whole country, at which stage there is a comprehensive geodetic survey for the country.
Geodetic surveying is the responsibility of the national surveying and mapping organization, which undertake geodetic surveys, using precise instruments and surveying techniques to a very high order of accuracy over relatively large areas. Apart from serving national interests, geodetic surveys also contribute towards a study of the size and shape of the earth.
Hydrographic surveys have traditionally been carried out for the compilation of nautical charts and the construction and maintenance of harbours. However, because of the increasing development of off-shore oil and natural gas exploitation, there is a corresponding increasing demand for hydrographic surveys.
The principles underlying land surveying and hydrographic surveying are essentially the same; however the surveying techniques and equipment used are obviously different. The scope of hydrographic surveying is wide, ranging from surveys of rivers and estuaries to surveys of off-shore sites for oil and natural gas exploitation and to surveys involving sea and ocean beds.
One well-known example of a hydrographic survey is the joint hydrographic surveys of the Straits of Malacca and Singapore carried out from 1969 to 1974 by Japan, Indonesia, Malaysia and Singapore. The objective was to promote navigational safety in view of the increasing number of vessels navigating the Straits and the obsolescence of old navigation charts which were based on surveys done up to the 1930s.
GEOGRAPHIC INFORMATION SYSTEM (GIS)
LAND INFORMATION SYSTEM (LIS)
Nowadays, the traditional surveying and mapping end products (such as topographic maps, geodetic control date, cadastral plans) are not sufficient for users. More value added spatial referenced information is required in order to support multidisciplinary applications for natural resources, environment, facility and utility management, infrastructure, economic development,..etc.
GIS/LIS technology has become a popular tool for the implementation of the above multidisciplinary applications. By virtue of his training and core expertise in data collection and data handling, a surveyor is in a natural position to progress beyond the traditional surveying and mapping operations, by engaging himself in spatial information management operations through GIS/LIS operations.
The role of a Land Surveyor can be summarised by its definition “A surveyor is a professional person with the academic qualifications and technical expertise to practise the science of measurement; to assemble and assess land and geographic related information; to use that information for the purpose of planning and implementing the efficient administration of the land, the sea and structures thereon; and to instigate the advancement and development of such practices.”
Source – https://rism.org.my/geomatic-and-land-surveying-division-gls/