hectare
{{short description|Metric unit of area}}
{{Infobox unit
| bgcolor =
| name = hectare
| image = Illustration of One Hectare.png
| caption = A visualisation of one hectare
| standard = Non-SI units mentioned in the SI
| quantity = Area
| symbol = ha
| units1 = SI base units:
| inunits1 = 104 m2
| units2 = Imperial and US customary units
| inunits2 = {{cvt|1|ha|yd2 acre|sigfig=5|disp=br|order=out|comma=gaps}}
}}
File:Comparison of units of area.png.]]
The hectare ({{IPAc-en|ˈ|h|ɛ|k|t|ɛər|,_|-|t|ɑːr}}; SI symbol: ha) is a non-SI metric unit of area equal to a square with 100-metre sides (1 hm2), that is, {{val|10000}} square metres ({{val|10000|u=m2}}), and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. An acre is about {{convert|1.000|acre|ha|disp=out|abbr=off}} and one hectare contains about {{convert|1.000|ha|acre|disp=out}}.
File:St. Enda's GAA ground, Omagh - geograph.org.uk - 556880.jpg. The playing field used in Gaelic football and hurling is a little over a hectare in size.]]
In 1795, when the metric system was introduced, the are was defined as 100 square metres, or one square decametre, and the hectare ("hecto-" + "are") was thus 100 ares or {{sfrac|1|100}} km2 ({{val|10000}} square metres). When the metric system was further rationalised in 1960, resulting in the International System of Units ({{tooltip|2=in French: Système International d'Unités|SI}}), the are was 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/decare daa ({{val|1000|u=m2}}) and are (100 m2) are not officially "accepted for use", they are still used in some contexts.
Description
{{anchor|table-comparison-of-area-units}}
| class="wikitable" style="float:right; padding:0 0 2em 3em; margin: .56em 0 0 .8em;"
|+Comparison of area units !Unit | SI |
| style="text-align:right;"
|1 ca |1 m2 | |
| style="text-align:right;"
|1 a |100 m2 | |
| style="text-align:right;"
|1 ha |10,000 m2 | |
| style="text-align:right;"
|100 ha |{{val|1000000|u=m2}} | |
| colspan="2"|non-SI comparisons | |
|---|---|
| non-SI||metric | |
| style="text-align:right;"
|0.3861 sq mi |1 km2 | |
| style="text-align:right;"
|2.471 acre |1 ha | |
| style="text-align:right;"
|{{val|107639|u=sq ft}} |1 ha | |
| style="text-align:right;"
|1 sq mi |259.0 ha | |
| style="text-align:right;"
|1 acre |0.4047 ha |
File:Trafalgar Square, London 2 - Jun 2009.jpg has an area of about one hectare.
{{cite web
|url = http://www.nao.org.uk/wp-content/uploads/2006/10/05061631.pdf
|title = Department for Environment, Food and Rural Affairs, and Rural Payments Agency; The Delays in Administering the 2005 Single Payment Scheme in England
|page=27
|publisher = National Audit Office
|date = 18 October 2006
}}]]
The hectare ({{IPAc-en|ˈ|h|ɛ|k|t|ɛər|,_|-|t|ɑː|r}}
{{cite web
|url = http://oxforddictionaries.com/view/entry/m_en_gb0370830#m_en_gb0370830
|archive-url = https://web.archive.org/web/20110101110815/http://oxforddictionaries.com/view/entry/m_en_gb0370830#m_en_gb0370830
|url-status = dead
|archive-date = 1 January 2011
|title = hectare
|publisher = Oxford Dictionaries
|access-date = 24 December 2010
}}), although not a unit of SI, is the only named unit of area that is accepted for use with SI units.{{citation|author= Bureau international des poids et mesures |year=2006 |url=http://www.bipm.org/utils/common/pdf/si_brochure_8_en.pdf |title=The International System of Units (SI) |version= 8th ed. |access-date=13 February 2008}} Chapter 5. The name was coined in French, from the Latin {{lang|la|ārea}}.Oxford English Dictionary, 1st edition [http://www.oed.com/view/Entry/10502 s.v.] 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,{{cite web |author1=BIPM |title=SI Brochure, Table 6 |url=http://www.bipm.org/en/publications/si-brochure/table6.html |access-date=17 November 2014 |date=2014 }} and it is the legal unit of measure in domains concerned with land ownership, planning, and management, including law (land deeds), agriculture, forestry, and town planning throughout the European Union,{{cite web | url = http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CONSLEG:1980L0181:20090527:EN:PDF| author = The Council of the European Communities | title = 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 | date=27 May 2009 | access-date=29 January 2010}} New Zealand and
Australia (since 1970).{{cite web | url = https://parlinfo.aph.gov.au/parlInfo/search/display/display.w3p;query=Id:%22publications/tabledpapers/HPP032016003235_2%22;src1=sm1 | author = Commonwealth of Australia | title = Metric Conversion Act | date=1970 | access-date=14 Aug 2020}}{{cite web | url = https://metricpioneer.com/australia/ | author = Metric Pioneer | title = Metric Pioneer | date=2020 | access-date=14 Aug 2020 }}
However, the United Kingdom,{{cite web|url=http://www.legislation.gov.uk/ukpga/1985/72/pdfs/ukpga_19850072_en.pdf
|title=Weights and Measures Act 1985|work=British Government|year=1985|access-date=17 December 2016}} the United States, Myanmar (Burma),
{{cite web
|url=https://www.cia.gov/library/publications/the-world-factbook/appendix/appendix-g.html
|archive-url=https://web.archive.org/web/20070613023743/https://www.cia.gov/library/publications/the-world-factbook/appendix/appendix-g.html
|url-status=dead
|archive-date=13 June 2007
|title=Appendix G – Weights and Measures
|work=The World Factbook
|year=2006
|publisher=CIA
|access-date=8 August 2006
}}{{cite web |work=MYA/01/008 Agriculture Sectore Review |url=http://www.agrifoodconsulting.com/ACI/uploaded_files/project_report/project_46_364535920.pdf#page=13 |title=Working Paper No. 6 – Agroindustry in Myanmar |archive-url=https://web.archive.org/web/20130515190933/http://www.agrifoodconsulting.com/ACI/uploaded_files/project_report/project_46_364535920.pdf |archive-date=15 May 2013 |url-status=dead }} and to some extent Canada, use the acre instead of the hectare for measuring surface or land area.{{Citation needed|date=August 2010}}
Some countries that underwent a general conversion from traditional measurements to metric measurements (e.g. Canada) required a resurvey when units of measure in legal descriptions relating to land were converted to metric units.{{Citation needed|date=February 2010}} Others, such as South Africa, published conversion factors which were to be used particularly "when preparing consolidation diagrams by compilation".
{{cite web
|url = http://www.lawsoc.co.za/webs/surveyorgeneral/2007_11_area_conversion.doc
|title = Instructions for the Conversions of Areas to Metric
|publisher = Law Society of South Africa
|date = November 2007
|access-date = 21 January 2011
|archive-date = 20 March 2018
|archive-url = https://web.archive.org/web/20180320105433/https://www.lawsoc.co.za/webs/surveyorgeneral/2007_11_area_conversion.doc
|url-status = dead
}}
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:[https://www.britannica.com/EBchecked/topic/259196/hectare Britannica.com, unit of measurement], accessed 30 October 2009
- Jerib ({{langx|fa|جریب}}) in Iran
- Djerib ({{langx|tr|cerip}}) in Turkey{{Cite EB1911|wstitle= Turkey |volume= 27 |last1= Caillard |first1= Vincent Henry Penalver |last2= Gibb |first2= Elias John Wilkinson |author2-link= Elias John Wilkinson Gibb | pages = 426–467; see page 442 second para |quote=Two categories of rent, fixed and proportional, are payable to the state by mine-owners. The fixed rent is 10 piastres per jerib (about {{val|10000}} square metres), to be paid whether the mine is worked or not. }}
- Gongqing ({{lang-zh|t=公頃|s=公顷|first=t|p=gōngqǐng}}) in China
- Manzana in Argentina
- Bunder in the Netherlands (until 1937)
{{cite web
|url = http://home.kpn.nl/vanadovv/Opp.html
|title = Oppervlakte
|trans-title = Area
|work = Eenheden, constanten en conversies [Units, constants and conversion]
|language = nl
|author = Oscar van Vlijmen
|date = 11 September 2006
|access-date = 15 January 2011
|archive-date = 19 June 2021
|archive-url = https://web.archive.org/web/20210619223013/https://home.kpn.nl/vanadovv/Opp.html
|url-status = dead
{{cite book
|url = https://archive.org/details/allereerstegron00ramagoog
|title = Allereerste Gronden der Cijferkunst
|author = Jacob de Gelder
|location = 's-Gravenhage and Amsterdam
|language = nl
|year = 1824
|page = [https://archive.org/details/allereerstegron00ramagoog/page/n179 156]
|publisher = de Gebroeders van Cleef
|trans-title=Introduction to Numeracy
|access-date =19 September 2012
}}
In Mexico, land area measurements are commonly given as combinations of hectares, ares, and centiares.{{Cite web |last= |title=Superficie de terrenos |url=https://nuevaescuelamexicana.sep.gob.mx/detalle-recurso/35466/ |access-date=2024-05-06 |website=Nueva Escuela Mexicana Digital |publisher=Secretariat of Public Education of Mexico |language=es}} These are commonly written separated by a hyphen; for example, 1-21-00.26 ha would mean 1 hectare, 21 are, and 0.26 centiare ({{val|12100.26|u=m2}}).
History
The metric system of measurement was first given a legal basis in 1795 by the French Revolutionary government. The law of 18 Germinal, Year III (7 April 1795) defined five units of measure:
{{cite web |url= http://aviatechno.free.fr/unites/nouveausys.php
|title = La loi du 18 Germinal an 3 " la mesure [républicaine] de superficie pour les terrains, égale à un carré de dix mètres de côté »
|language = fr
|trans-title=The law of 18 Germanial year 3 "The [Republican] measure of land area equivalent to a ten-metre square"
|publisher = Le CIV (Centre d'Instruction de Vilgénis) – Forum des Anciens
|access-date = 2 March 2010
}}
- The :metre for length
- The are (100 m2) for area [of land]
- The stère (1 m3) for volume of stacked firewood
{{cite web
|url = http://www.utc.fr/~tthomass/Themes/Unites/unites/infos/stere/Le%20stere.pdf
|title = Le stère
|work = Tout sur les unités de mesure [All the units of measure]
|language = fr
|author = Thierry Thomasset
|publisher = Université de Technologie de Compiègne
|access-date = 21 March 2011
|archive-url = https://web.archive.org/web/20110721011132/http://www.utc.fr/~tthomass/Themes/Unites/unites/infos/stere/Le%20stere.pdf
|archive-date = 21 July 2011
|url-status = dead
}}
In 1960, when the metric system was updated as the International System of Units (SI), the are did not receive international recognition. The International Committee for Weights and Measures ({{tooltip|2=in French: Comité international des poids et mesures|CIPM}}) makes no mention of the are in 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".
{{cite web
|url=https://www.bipm.org/documents/20126/41483022/SI-Brochure-9.pdf
|title=SI brochure (Chapter 4; Table 8)
|publisher=International Bureau of Weights and Measures
|year=2006
|access-date=28 August 2023
|df=dmy-all
}}
In 1972, the European Economic Community (EEC) passed directive 71/354/EEC,
{{cite web
| url = http://eur-lex.europa.eu/Notice.do?mode=dbl&lang=en&lng1=en,nl&lng2=da,de,el,en,es,fr,it,nl,pt,&val=22924:cs&page=1&hwords=
| title = Council Directive of 18 October 1971 on the approximation of laws of the member states relating to units of measurement, (71/354/EEC)
| access-date = 7 February 2009
| archive-date = 25 April 2009
| archive-url = https://web.archive.org/web/20090425221644/http://eur-lex.europa.eu/Notice.do?mode=dbl&lang=en&lng1=en,nl&lng2=da,de,el,en,es,fr,it,nl,pt,&val=22924:cs&page=1&hwords=
| url-status = dead
}} 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 the are (and implicitly the hectare) whose use was limited to the measurement of land.
Unit family
The names centiare, deciare, decare and hectare are derived by adding the standard metric prefixes to the original base unit of area, the are.
= Decimilliare =
The decimilliare (dma, sometimes seen in cadastre area evaluation of real estate plots) is {{sfrac|1|10,000}} are or one square decimetre.{{cite book |url=https://books.google.com/books?id=QaDooblqBikC&pg=PA363 |title=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 |first1=Horatio Nelson |last1=Robinson |first2=Daniel W. |last2=Fish |publisher=Ivison, Blakeman, Taylor |year=1858 |page=363 }} Such usage of a double prefix is non-standard. The decimilliare is (100 mm)2 or roughly a four-inch-by-four-inch square.
= Centiare =
The centiare is one square metre.{{cite dictionary |url=https://www.dictionary.com/browse/centiare |title=centiare |access-date=16 October 2019 |dictionary=Dictionary.com |publisher=Dictionary.com, LLC}}{{cite dictionary |url=https://www.collinsdictionary.com/dictionary/english/centiare |title=centiare |dictionary=Collins Dictionary |publisher=Collins Publishers |access-date=16 October 2019}}
= Deciare =
= Are =
{{Redirect|Are (unit)|the English verb|To be (disambiguation){{!}}To Be}}
{{cite web
|url = http://oxforddictionaries.com/view/entry/m_en_gb0038720?rskey=sLRO50&result=2#m_en_gb0038720
|archive-url = https://archive.today/20130130231454/http://oxforddictionaries.com/view/entry/m_en_gb0038720?rskey=sLRO50&result=2%23m_en_gb0038720
|url-status = dead
|archive-date = 30 January 2013
|title = are
|publisher = Oxford Dictionaries
|access-date = 24 December 2010
}} or {{IPAc-en|ɛər}}{{cite web |url=http://www.macmillandictionary.com/dictionary/american/are_7 |title=are – definition. American English definition of are by Macmillan Dictionary |publisher=Macmillandictionary.com |access-date=20 May 2012 }}) is a unit of area, equal to 100 square metres ({{val|10|×|10|u=m}}), used for measuring land area. It was defined by older forms of the metric system, but is now outside the modern International System of Units (SI).{{cite web |url=http://www.bipm.org/en/si/si_brochure/ |title=SI brochure (8th edition) |date=March 2006 |publisher=BIPM }} It is still commonly used in speech to measure real estate, in particular in Indonesia, India, and in various European countries.
In Russian and some other languages of the former Soviet Union, the are is called {{lang|ru-Latn|sotka}} (сотка: 'a hundred', i.e. 100 m2 or {{sfrac|1|100}} hectare). It is used to describe the size of suburban dacha or allotment garden plots or small city parks where the hectare would be too large. Many Russian dachas are 6 ares in size (in Russian, {{lang|ru|шесть соток}}).
= Decare =
The decare or dekare ({{IPAc-en|ˈ|d|ɛ|k|ɑːr|,_|-|ɛər}}) is derived from deca and are, and is equal to 10 ares or 1000 square metres. It is used in Norway
{{cite web
|url = http://www.ssb.no/korn_en/arkiv/art-2003-03-19-01-en.html
|title = Decrease in total grain yield
|work = Grain and oil seeds, area and production, 2002
|publisher = Statistics Norway
|access-date = 16 November 2010
}} and in the former Ottoman areas of the Middle East and Bulgaria
{{cite web
|url=http://www.bnr.bg/sites/en/Economy/Pages/0510Marketofagriculturalland.aspx
|title=Market of agricultural land in Bulgaria
|date=5 October 2010
|publisher=BNR Radio Bulgaria
|access-date=16 November 2010
|url-status=dead
|archive-url=https://web.archive.org/web/20101022061357/http://www.bnr.bg/sites/en/Economy/Pages/0510Marketofagriculturalland.aspx
|archive-date=22 October 2010
|df=dmy-all
}} as a measure of land area. The names of the older land measures of similar size are usually used, redefined as exactly one decare:
- {{lang|el-Latn|Stremma}} in GreeceΛεξικό της κοινής Νεοελληνικής (Dictionary of Modern Greek), Ινστιτούτο Νεοελληνικών Σπουδών, Θεσσαλονίκη, 1998. {{ISBN|960-231-085-5}}
- {{lang|tr|Dunam, dunum, dulum, donum, or dönüm}} in the Balkans, Israel, Palestine, Jordan, Lebanon, Syria, and Turkey{{cite book|last1= El-Eini |first1= Roza I.M. |title= Mandated landscape: British imperial rule in Palestine, 1929–1948 |url= https://books.google.com/books?id=ekQOAAAAQAAJ |access-date= 5 May 2009 |year= 2006 |publisher= Routledge |isbn= 978-0-7146-5426-3 |page= xxiii |chapter= Currency and Measures |chapter-url= https://books.google.com/books?id=ekQOAAAAQAAJ&q=El-Eini+%22Mandated+Landscape%22 }}
- {{lang|no|Mål}} in Norway.
Conversions
| class="wikitable" |
| +Metric and British imperial/United States customary comparisons
!Unit name !Symbol !Multiple of !Fraction of !Length of !SI equivalents !British imperial/United States customary |
| centiare
| style="text-align:center;" |ca | | style="text-align:center;" |0.1 da | style="text-align:right;" |{{val|1|u=m}} | style="text-align:center;" |{{val|1|u=m2}} | style="text-align:center;" |{{convert|1.000000|m2|ft2|disp=out|lk=out|comma=gaps}} |
| deciare
| style="text-align:center;" |da | style="text-align:center;" |10 ca | style="text-align:center;" |0.1 a | style="text-align:right;" |{{val|3.1623|u=m}} | style="text-align:center;" |{{val|10|u=m2}} | style="text-align:center;" |{{convert|10.00000|m2|yd2|disp=out|lk=out|comma=gaps}} |
| are
| style="text-align:center;" |a{{cite book|title=BS350:Part 1:1974 Conversion factors and tables Part 1. Basis of tables. Conversion factors|date=1974|publisher=British Standards Institution|page=7}} | style="text-align:center;" |10 da | style="text-align:center;" |0.1 daa | style="text-align:right;" |{{val|10|u=m}} | style="text-align:center;" |{{val|100|u=m2}} | style="text-align:center;" |{{convert|100.0000|m2|sqperch|disp=out|lk=out|comma=gaps}} |
| decare
| style="text-align:center;" |daa | style="text-align:center;" |10 a | style="text-align:center;" |0.1 ha | style="text-align:right;" |{{val|31.623|u=m}} | style="text-align:center;" |{{val|1000|u=m2}} | style="text-align:center;" |{{convert|1000.000|m2|rood|disp=out|lk=out|comma=gaps}} |
| hectare
| style="text-align:center;" |ha | style="text-align:center;" |10 daa | style="text-align:center;" |0.01 km2 | style="text-align:right;" |{{val|100|u=m}} | style="text-align:center;" |{{val|10000|u=m2}} | style="text-align:center;" |{{convert|10000.00|m2|acre|disp=out|comma=gaps}} |
| square kilometre
| style="text-align:center;" |{{val|u=km2}} | style="text-align:center;" |100 ha | | style="text-align:right;" |{{val|1000|u=m}} | style="text-align:center;" |{{val|1000000|u=m2}} | style="text-align:center;" |{{convert|1000000.|m2|mi2|disp=out|lk=out|comma=gaps}} |
The most commonly used units are in bold.
One hectare is also equivalent to:
- 1 square hectometre
- 1.008 {{lang|ja-Latn|chō}} (Japan)
- 2.381 {{lang|ar-Latn|feddan}} (Egypt)
- 6.25 {{lang|th-Latn|rai}} (Thailand)
- 10 {{lang|ar-Latn|dunam}} or {{lang|ar-Latn|dönüm}} (Middle East){{cite book
|url = https://archive.org/details/encyclopaediaofs0000card
|url-access = registration
|quote = metrication malta.
|title = Encyclopaedia of scientific units, weights, and measures: their SI equivalences and origins
|author = François Cardarelli
|page = [https://archive.org/details/encyclopaediaofs0000card/page/97 97]
|publisher = Springer Verlag
|location = London, Berlin and Heidelberg
|year = 2003
|isbn = 1-85233-682-X
|access-date = 29 March 2011}}
- 10 {{lang|el-Latn|stremmata}} (Greece)
- 15 {{lang|zh-Latn|mǔ}} or 0.15 {{lang|zh-Latn|qǐng}}{{cite web
|url = http://www.mandarintools.com/measures.html
|title = Chinese Measurements – Units of Area
|work = On-line Chinese Tools
|access-date = 24 December 2010}}
Unicode
The Unicode character {{unichar|33CA|SQUARE ha}}, in the CJK Compatibility block, is intended for compatibility with pre-existing East Asian character codes.{{Cite web |last=Unicode.org |title=CJK Compatibility block |url=https://www.unicode.org/charts/PDF/U3300.pdf}} It is not intended for use in alphabetic contexts.
{{unichar|3336}} is a combination of {{lang|ja|ヘクタール}} ({{Transliteration|ja|hekutāru}}), the Japanese translation of "hectare".
See also
References
{{reflist|2}}
External links
{{commons}}
{{EB1911 poster|Acre (land measure)}}
{{wiktionary|hectare}}
- [https://web.archive.org/web/20141111155820/http://www.bipm.org/en/publications/si-brochure/table6.html Official SI website: Table 6. Non-SI units accepted for use with the International System of Units]
{{SI units}}
{{Use dmy dates|date=June 2016}}