Surveying in Oceania

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A vulcanologist takes theodolite measurements on the crater lake of Mt Ruapehu.

Surveying in Australia and New Zealand is triangulation-based. As both countries were colonised by Great Britain during the same period of history, their survey systems share many similarities. Although they inherited the title deed system from the United Kingdom, a distinctive feature is the Torrens System, where real estate records are held in a central deposit and guaranteed by the state.

Early history

The first accurate mapping of both countries was compiled during the voyages of Captain Cook. Cook's experience in creating nautical charts of the eastern seaboard of Canada was an important factor in his appointment as captain of the voyage observing the transit of Venus. As he sailed the coastlines, he charted the bays and coastlines.

Survey system of Australia

Most states appointed surveyors-general early in their history. These officials were responsible for setting up reliable systems to record land purchases and claims. The current Australian survey system is the geocentric datum of Australia, established in 1994.[1] It was adopted nationally on 1 January 2000.[2] Surveying is regulated at a federal level by Geoscience Australia.[3]

Initially surveys were conducted using magnetic bearings. Later measurements were made on county arbitrary meridians, where surveys in each county were based off an initial point determined by government surveyors. In 1966, the first nationwide system, the Australian geodetic datum (AGD) was established.[4]

Early exploration

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Early surveying efforts concentrated on finding suitable town sites. Many towns in Australia were established by dividing a suitable site into small plots of land that were sold to English residents who then emigrated. Other exploration expeditions were made to the interior in an attempt to find fertile land.[5]

New South Wales

The first attempts to regulate surveying in New South Wales was in 1836. In 1876, use of the circumferentor was prohibited. The theodolite supplanted it as a more accurate measurer of angles.[6]

Western Australia

A fully qualified surveyor in western Australia is known as a licensed surveyor. The title is administered by the Land Surveyors Licensing Board of Western Australia.

Survey system of New Zealand

History

Prior to European colonisation, New Zealand was divided into territories of tribes (Iwi) and subtribes (hapu). Boundaries were defined by landmarks which were remembered in chants and oral tradition.[7][8] Land was held by customary possession, gifted, or by conquest and occupation.[7]

Sales of land to European colonists prior to 1840 were not regulated. Disputes arose mainly in areas where tribal possession was unclear.

Following the Treaty of Waitangi in 1840, all lands of New Zealand came under the dominion of the British crown. The treaty allowed the tribes possession of their customary lands. Europeans wanting to purchase land negotiated through a government commission. If negotiations were successful, the applicant was given a crown grant that gave them ownership under British law. The purchases prior to 1840 were known as old land claims and required to go through the same process. Many of these claims were reduced in size from the original agreements.[9]

The position of surveyor-general was created in the royal instructions of 1840. The first regulations for surveying were established in 1842, when surveyors were required to deposit their licenses with the surveyor general's office to be returned upon completion of a survey. In 1852, provinces were established and each established a survey department. These were often underfunded and most failed to systemise surveys in their territory, making boundaries unreliable because of gaps and overlaps between abutting surveys. Some small triangulation networks were established, and some cities established survey control points on routes known as standard traverses that surveyors could use as a basis for local surveys. In Otago, true north was determined at six points throughout the province. Local surveys could be linked to these points so that their angle measurements were consistent throughout the district. The districts were known as meridional circuits, a term that has persisted in New Zealand surveying. [9]

In 1875 Major H S Palmer of the Ordnance Survey of Great Britain presented a damning report on the state of the survey system to the New Zealand Parliament. He recommended that a unified map projection was adopted and a single system of reference points was established across the country. In 1876, the provinces were abolished and the survey departments were combined.[10] The chief surveyor of the Otago province, John Turnbull Thomson, was made surveyor-general of the new government survey department. Thompson established meridional circuits throughout the country as well as reorganising the way land records were identified and recorded. By 1880, the small original triangulation networks had been extended and joined throughout New Zealand.[9]

Geodetic surveys

In the years following Major Palmer's report, triangulation had been extended throughout New Zealand, but accuracy had been found wanting. It was not until 1921 that Surveyor-General W.T. Neill began work on a system that would create accurate reference points throughout New Zealand. In 1923, the first baseline was measured near Kaingaroa. From 1930 onward, observations were made at night to improve accuracy. The longest observation was 120 kilometres (75 mi) across Cook Strait. Work continued through World War II as the project was allowed topographical maps for military use to be quickly compiled. The last fieldwork was completed in early 1949, and the system became known as the New Zealand Geodetic Datum 1949. [9]

The 1949 datum was updated in 2000. To ease GPS measurement the new system was slightly shifted to become geocentric (the origin point of the system coincides with the centre of the Earth). It was also designed to be semi-dynamic, to cope better with seismic movement. This system is called the New Zealand Geodetic Datum 2000, and includes the NZ Transverse Mercator projection that topographical maps are published in.[11]

These geodetic activities are responsible for the ubiquitous trig stations that reside mostly at the top of many hills throughout New Zealand.

Current system

Cadastral surveying in New Zealand is governed by the Cadastral Survey Act 2002, which defines legal bodies that deal with aspects of the profession. The act devolves power to create specific regulations to the surveyor-general, who periodically issues the surveyor-general's rules for cadastral surveys. The Land Transfer Act 1952 also influences the way surveys are done.

The Torrens system of land registration was introduced in the Land Transfer Act 1870. The act introduced a system where land title is held in a register as opposed to the previous system that registered the document containing the title information. It therefore made it unnecessary to search the history of a title, and made titles indefeasible, meaning that it cannot be claimed by persons other than the registered owner.

A separate system exists in parallel with the general land titles for land held in common by Māori as a tribe. This is controlled by the Te ture Whenua Maori (Maori Land) Act 1993. In 1980, 4.5% of New Zealand land was held in the Māori land system.[7] This does not include land held by Māori individuals in the general land system.

A surveyor who has fulfilled the requirements to legally sign subdivision plans is known as a licensed cadastral surveyor.

Construction surveying is not regulated at the state level in New Zealand. However, matters relating to surveying may require certification by a registered professional surveyor under contract law or local authority regulations.

Surveying in New Zealand uses whole circle (azimuth) bearings. Another oddity is the convention of writing coordinates where the northing is written before the easting, at odds with much of the rest of the world.

Professional associations

New Zealand Institute of Surveyors was established in 1888 after an earlier attempt in 1881.

The Surveying & Spatial Sciences Institute (SSSI)

The Institution of Surveyors NSW Inc

The Institution of Surveyors Victoria

Queensland Spatial & Surveying Association

Surveyors Board of South Australia.

The Australian Institute of Mine Surveyors

Australasian Institute of Marine Surveyors

The Intergovernmental Committee on Surveying and Mapping (ICSM)

References

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