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Hectare

From Wikipedia, the free encyclopedia
hectare
A visualisation of one hectare
General information
Unit systemNon-SI unit accepted for use with SI
Unit ofArea
Symbolha
Conversions
1 hain...... is equal to...
SI base units:104m2
Imperial and US customary units11,960 sq yd
2.4711 acres
Image comparing the hectare (the small blue area at lower left) to other units. The entire yellow square is onesquare mile.

Thehectare(/ˈhɛktɛər,-tɑːr/;SIsymbol:ha) is anon-SImetric unitofareaequal to a square with 100-metresides (1 hm2), that is, 10,000 square metres (10,000 m2), and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. Anacreis about 0.405 hectares and one hectare contains about 2.47 acres.

St. Enda's GAA ground, inOmagh.The playing field used inGaelic footballandhurlingis a little over a hectare in size.

In 1795, when the metric system was introduced, thearewas defined as 100square metres,or one squaredecametre,and the hectare ( "hecto-"+" are ") was thus 100aresor1⁄100km2(10,000 square metres). When the metric system was further rationalised in 1960, resulting in theInternational System of Units(SI), thearewas not included as a recognised unit. The hectare, however, remains as a non-SI unit accepted for use with the SI and whose use is "expected to continue indefinitely". Though the dekare/decaredaa(1,000 m2) andare(100 m2) are not officially "accepted for use", they are still used in some contexts.

Description

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Comparison ofarea units
Unit SI
1 ca 1 m2
1 a 100 m2
1 ha 10,000 m2
100 ha 1,000,000 m2
1 km2
non-SI comparisons
non-SI metric
0.3861 sq mi 1 km2
2.471 acre 1 ha
107,639 sq ft 1 ha
1 sq mi 259.0 ha
1 acre 0.4047 ha
Trafalgar Squarehas an area of about one hectare.[1]

The hectare (/ˈhɛktɛər,-tɑːr/[2]), although not a unit of SI, is the only named unit of area that isaccepted for use with SI units.[3]The name was coined in French, from the Latinārea.[4]In practice the hectare is fully derived from the SI, being equivalent to a square hectometre. It is widely used throughout the world for the measurement of large areas of land,[5]and it is the legal unit of measure in domains concerned with land ownership, planning, andmanagement,including law (land deeds), agriculture,forestry,andtown planningthroughout theEuropean Union,[6]New Zealand and Australia(since 1970).[7][8] However, the United Kingdom,[9]the United States, Myanmar (Burma),[10][11]and to some extent Canada, use theacreinstead of the hectare for measuring surface or land area.[citation needed]

Some countries that underwent a general conversion from traditional measurements tometricmeasurements (e.g. Canada) required a resurvey when units of measure in legal descriptions relating to land were converted to metric units.[citation needed]Others, such as South Africa, published conversion factors which were to be used particularly "when preparing consolidation diagrams by compilation".[12]

In many countries, metrification redefined or clarified existing measures in terms of metric units. The following legacy units of area have been redefined as being equal to one hectare:[13]

In Mexico, land area measurements are commonly given as combinations of hectares, ares, and centiares.[17]These are commonly written separated by adash;for example,1-21-00.26 hawould mean 1 hectare, 21 ares, and 0.26 centiares (12,100.26 m2).

History

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The metric system of measurement was first given a legal basis in 1795 by theFrench Revolutionarygovernment. The law of18 Germinal, Year III(7 April 1795) defined five units of measure:[18]

  • Themetrefor length
  • Theare(100 m2) for area [of land]
  • Thestère(1 m3) for volume of stacked firewood[19]
  • Thelitre(1 dm3) for volumes of liquid
  • Thegramfor mass

In 1960, when the metric system was updated as the International System of Units (SI), thearedid not receive international recognition. TheInternational Committee for Weights and Measures(CIPM) makes no mention of thearein the 2019 edition of the SI brochure, but classifies the hectare as a "Non-SI unit accepted for use with the International System of Units".[20]

In 1972, theEuropean Economic Community(EEC) passed directive 71/354/EEC,[21]which catalogued the units of measure that might be used within the Community. The units that were catalogued replicated the recommendations of the CGPM, supplemented by a few other units including theare(and implicitly thehectare) whose use was limited to the measurement of land.

Unit family

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Definition of ahectareand of anare

The namescentiare,deciare,decareandhectareare derived by adding the standardmetric prefixesto the original base unit of area, theare.

Decimilliare

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Thedecimilliare(dma, sometimes seen incadastrearea evaluation of real estate plots) is1⁄10,000are or one square decimetre.[22]Such usage of adouble prefixis non-standard. The decimilliare is (100 mm)2or roughly a four-inch-by-four-inch square.

Centiare

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Thecentiareis one square metre.[23][24]

Deciare

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Thedeciare(rarely used) is ten square metres.[25]

Are

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"Are (unit)" redirects here. For the English verb, seeTo Be.

Theare(/ɑːr/[26]or/ɛər/[27]) is a unit of area, equal to 100 square metres (10 m × 10 m), used for measuring land area. It was defined by older forms of themetric system,but is now outside the modernInternational System of Units(SI).[28]It is still commonly used in speech to measure real estate, in particular in Indonesia, India, and in various European countries.

InRussianand some other languages of the formerSoviet Union,theareis calledsotka(‹See Tfd›Russian:сотка:'a hundred', i.e. 100 m2or1⁄100hectare). It is used to describe the size of suburbandachaorallotment gardenplots or small city parks where the hectare would be too large. Many Russian dachas are 6 ares in size (in Russian,шесть соток).

Decare

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Thedecareordekare(/ˈdɛkɑːr,-ɛər/) is derived fromdecaandare,and is equal to 10 ares or 1000 square metres. It is used inNorway[29]and in the formerOttomanareas of theMiddle EastandBulgaria[30]as a measure of land area. The names of the older land measures of similar size are usually used, redefined as exactly one decare:

Conversions

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Metric and British imperial/United States customary comparisons
Unit name Symbol Multiple of
preceding unit 		Fraction of
succeeding unit 		Length of
square side 		SI equivalents British imperial/United States customary
equivalents
centiare ca 0.1 da 1 m 1 m2 10.76391sq ft
deciare da 10 ca 0.1 a 3.1623 m 10 m2 11.95990sq yd
are a[33] 10 da 0.1 daa 10 m 100 m2 3.95369perches
decare daa 10 a 0.1 ha 31.623 m 1000 m2 0.988422roods
hectare ha[5] 10 daa 0.01 km2 100 m 10000m2 2.47105 acres
square kilometre km2 100 ha 1000 m 1000000m2 0.386102sq mi
An acre shown inside a hectare for size comparison

The most commonly used units are inbold.

One hectare is also equivalent to:

Unicode

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TheUnicodecharacterU+33CA㏊SQUARE HA,in theCJK Compatibilityblock, is intended for compatibility with pre-existing East Asian character codes.[36]It is not intended for use in Alpha betic contexts. U+3336㌶SQUARE HEKUTAARUis a combination ofヘクタール(hekutāru), the Japanese translation of "hectare".

See also

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References

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  1. ^"Department for Environment, Food and Rural Affairs, and Rural Payments Agency; The Delays in Administering the 2005 Single Payment Scheme in England"(PDF).National Audit Office. 18 October 2006. p. 27.
  2. ^"hectare".Oxford Dictionaries. Archived fromthe originalon 1 January 2011.Retrieved24 December2010.
  3. ^Bureau international des poids et mesures (2006),The International System of Units (SI)(PDF),8th ed.,retrieved13 February2008Chapter 5.
  4. ^Oxford English Dictionary,1st editions.v.
  5. ^abBIPM (2014)."SI Brochure, Table 6".Retrieved17 November2014.
  6. ^The Council of the European Communities (27 May 2009)."Council Directive 80/181/EEC of 20 December 1979 on the approximation of the laws of the Member States relating to Unit of measurement and on the repeal of Directive 71/354/EEC".Retrieved29 January2010.
  7. ^Commonwealth of Australia (1970)."Metric Conversion Act".Retrieved14 August2020.
  8. ^Metric Pioneer (2020)."Metric Pioneer".Retrieved14 August2020.
  9. ^"Weights and Measures Act 1985"(PDF).British Government.1985.Retrieved17 December2016.
  10. ^ "Appendix G – Weights and Measures".The World Factbook.CIA.2006. Archived fromthe originalon 13 June 2007.Retrieved8 August2006.
  11. ^"Working Paper No. 6 – Agroindustry in Myanmar"(PDF).MYA/01/008 Agriculture Sectore Review.Archived fromthe original(PDF)on 15 May 2013.
  12. ^"Instructions for the Conversions of Areas to Metric".Law Society of South Africa. November 2007. Archived fromthe originalon 20 March 2018.Retrieved21 January2011.
  13. ^Britannica, unit of measurement,accessed 30 October 2009
  14. ^Caillard, Vincent Henry Penalver;Gibb, Elias John Wilkinson(1911)."Turkey".InChisholm, Hugh(ed.).Encyclopædia Britannica.Vol. 27 (11th ed.). Cambridge University Press. pp. 426–467, see page 442 second para.Two categories of rent, fixed and proportional, are payable to the state by mine-owners. The fixed rent is 10 piastres perjerib(about 10,000 square metres), to be paid whether the mine is worked or not.
  15. ^Oscar van Vlijmen (11 September 2006)."Oppervlakte"[Area].Eenheden, constanten en conversies [Units, constants and conversion](in Dutch). Archived fromthe originalon 19 June 2021.Retrieved15 January2011.
  16. ^Jacob de Gelder (1824).Allereerste Gronden der Cijferkunst[Introduction to Numeracy] (in Dutch). 's-Gravenhage and Amsterdam: de Gebroeders van Cleef. p.156.Retrieved19 September2012.
  17. ^"Superficie de terrenos".Nueva Escuela Mexicana Digital(in Spanish).Secretariat of Public Education of Mexico.Retrieved6 May2024.
  18. ^"La loi du 18 Germinal an 3" la mesure [républicaine] de superficie pour les terrains, égale à un carré de dix mètres de côté » "[The law of 18 Germanial year 3 "The [Republican] measure of land area equivalent to a ten-metre square" ] (in French). Le CIV (Centre d'Instruction de Vilgénis) – Forum des Anciens.Retrieved2 March2010.
  19. ^Thierry Thomasset."Le stère"(PDF).Tout sur les unités de mesure [All the units of measure](in French). Université de Technologie de Compiègne. Archived fromthe original(PDF)on 21 July 2011.Retrieved21 March2011.
  20. ^"SI brochure (Chapter 4; Table 8)"(PDF).International Bureau of Weights and Measures.2006.Retrieved28 August2023.
  21. ^"Council Directive of 18 October 1971 on the approximation of laws of the member states relating to units of measurement, (71/354/EEC)".Archived fromthe originalon 25 April 2009.Retrieved7 February2009.
  22. ^Robinson, Horatio Nelson; Fish, Daniel W. (1858).Robinson's Progressive Practical Arithmetic: Containing the Theory of Numbers in Connection with Concise Analytic and Synthetic Methods of Solution, and Designed as a Complete Text-book on this Science for Common Schools and Academies.Ivison, Blakeman, Taylor. p. 363.
  23. ^"centiare".Dictionary.Dictionary, LLC.Retrieved16 October2019.
  24. ^"centiare".Collins Dictionary.Collins Publishers.Retrieved16 October2019.
  25. ^"deciare".Merriam Webster Dictionary.Merriam-Webster, Incorporated.Retrieved16 October2019.
  26. ^"are".Oxford Dictionaries.Retrieved24 December2010.[dead link]
  27. ^"are – definition. American English definition of are by Macmillan Dictionary".Macmillandictionary.Retrieved20 May2012.
  28. ^"SI brochure (8th edition)".BIPM. March 2006.
  29. ^ "Decrease in total grain yield".Grain and oil seeds, area and production, 2002.Statistics Norway.Retrieved16 November2010.
  30. ^"Market of agricultural land in Bulgaria".BNR Radio Bulgaria. 5 October 2010. Archived fromthe originalon 22 October 2010.Retrieved16 November2010.
  31. ^Λεξικό της κοινής Νεοελληνικής (Dictionary of Modern Greek), Ινστιτούτο Νεοελληνικών Σπουδών, Θεσσαλονίκη, 1998.ISBN960-231-085-5
  32. ^El-Eini, Roza I.M. (2006)."Currency and Measures".Mandated landscape: British imperial rule in Palestine, 1929–1948.Routledge.p. xxiii.ISBN978-0-7146-5426-3.Retrieved5 May2009.
  33. ^BS350:Part 1:1974 Conversion factors and tables Part 1. Basis of tables. Conversion factors.British Standards Institution. 1974. p. 7.
  34. ^François Cardarelli (2003).Encyclopaedia of scientific units, weights, and measures: their SI equivalences and origins.London, Berlin and Heidelberg: Springer Verlag. p.97.ISBN1-85233-682-X.Retrieved29 March2011.metrication malta.
  35. ^"Chinese Measurements – Units of Area".On-line Chinese Tools.Retrieved24 December2010.
  36. ^Unicode.org."CJK Compatibility block"(PDF).
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Wikisourcehas the text of the1911Encyclopædia Britannicaarticle "Acre (land measure)".
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