Quadripoint
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In geography, a quadripoint is a point on the Earth that touches four distinct regions. Such points are often called "four corners", from the corners of the four regions meeting there[1]
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[edit] International quadripoints
At present there are no generally recognized quadripoints involving four different countries, although a weak argument could be made that one exists between Namibia, Zambia, Zimbabwe and Botswana at the thalweg confluence of the Zambezi River with the Chobe River near Kazungula. The various boundary definitions involved are subject to differing and disputed interpretations; only one combination of interpretations will produce a quadripoint. [2] [3].
[edit] Close calls
If the Kazungula case above is not accepted as a quadripoint, it is the place where tripoints are closest together, as the maximum distance between the tripoints is no more than a few hundred metres.
Where two tripoints occur very close to each other, they can look like a quadripoint on a map with a sufficient scale. For example, the Kazakhstan/Russia/People's Republic of China tripoint is only 40 km from Friendship Peak, the Russia/Mongolia/People's Republic of China tripoint. It may look like a quadripoint on a large-scale map, but at more detailed resolution, it is clear that Kazakhstan and Mongolia never touch[4].
Although four countries border Lake Chad, there is no quadripoint of Chad, Niger, Nigeria, and Cameroon within the lake.
Similarly, the Gulf of Aqaba in the Red Sea borders four countries, but does not contain a quadripoint of Jordan, Saudi Arabia, Egypt, and Israel.
Some political maps of the South Pacific enclose many island nations within straight lines drawn along parallels of latitude or meridians of longitude, often with a maritime quadripoint for Solomon Islands, Tuvalu, Kiribati, and Nauru[5]. This is not a meaningful quadripoint, as the lines are simply cartographic conveniences to indicate which country the landmasses within it belong to; they do not correspond to international boundaries, many of which are undefined, or to territorial waters or Exclusive Economic Zones.[6]
[edit] Previously existing four-country points
Between 1839 and 1919 there was a four-country point at the convergence of Belgium, Prussia/Germany, the Netherlands, and Moresnet. [1] [2]
From 1922 to 1991 there was de facto a quadripoint between Iraq, Kuwait, Kingdom of Nejd/Saudi Arabia and the Saudi-Iraqi neutral zone, although precise boundaries were never specified by the three sovereign states.
[edit] Fewer than four countries
There are quadripoints where four border lines touch each other at one point, but involving fewer than four countries. This occurs with a practical exclave which touches the main territory (or another exclave) at a single point. The Belgian enclaves H1 and H2 in Baarle-Hertog touch each other at one such point, while the Netherlands also crosses it[7].
Similarly, the Austrian town of Jungholz lies totally within Germany except that it borders Austria at one single point.
Cooch Behar in India is linked with Bangladesh at one point.
[edit] Secondary quadripoints
A secondary quadripoint (or "quadrisecondary point") is the meeting of four political subdivisions (for example, provinces, states, or cantons). The four subdivisions may all belong to one country, or they may involve two or three different countries.
By analogy, one could speak of tertiary quadripoints ("quadritertiary points") where, for example, four different towns meet at one point. However, these are not considered particularly interesting. For example, many of the counties of Nebraska are demarcated as squares in a grid.
[edit] Trinational
At , there appears to be a trinational secondary quadripoint: to the northwest is Russia (specifically the Russian exclave Kaliningrad Oblast); to the northeast Lithuania; and to the southwest and southeast two Voivodships (provinces) of Poland: Warmian-Masurian Voivodship and Podlasie Voivodship.[8] [3]
At or around , there appears to be another trinational secondary quadripoint: to the north is Saudi Arabia, to the southeast is Oman, and to the southwest two Governorates of Yemen: Hadhramaut Governorate to the westsouthwest and Al Mahrah Governorate to the southsouthwest.[8]
[edit] Binational
The three German states Bavaria, Saxony, and Thuringia, do not form a quadripoint with the Czech Republic; nevertheless it is frequently commented on.
On the border of Sweden and Norway, at , there appears to be a binational secondary quadripoint where two Counties of Norway, Nord-Trøndelag and Nordland, meet two Counties of Sweden, Västerbotten County and Jämtland County.[8] [4]
[edit] National
The Four Corners is the only point in the United States of America where four states meet: Colorado, Utah, New Mexico, and Arizona.
In Canada, the point at may be a true quadripoint, as indicated on some maps [5] but it might just be a close call, as indicated by other maps [6] (see Four Corners (Canada)). The political units involved are two provinces, Saskatchewan and Manitoba (southwest and southeast of the point, respectively) and two territories, Northwest Territories and Nunavut (northwest and northeast of the point, respectively). Before the creation of Nunavut in 1999, this was a tripoint. In the legal definition of Nunavut [7], it appears that the Parliament of Canada did intend to create a true quadripoint. However, it is questionable whether the boundary of Saskatchewan and Manitoba falls precisely on the meridian of 102°W under the WGS84 geodetic system.
Four provinces in Mindanao island, Philippines meet at a point (probably at one of the three peaks of Mt. Apo): Bukidnon of Northern Mindanao Region, Davao del Norte and Davao del Sur of Davao Region, and Cotabato Province of SOCCSKSARGEN. It is the same point where the three regions: Northern Mindanao Region, Davao Region and SOCCSKSARGEN, meet.
[edit] United Kingdom
An analysis of county quadpoints in the United Kingdom is complicated by the fact that the borders and numbers of counties have changed several times in the last century (see Administrative counties of England). However, through it all there has only been one true quadpoint; it lies just south west of Stamford – where Rutland, Lincolnshire, Cambridgeshire and Northamptonshire meet. ()
Following the changes of 1974, the Stamford quadpoint was unchanged. The 1995 Unitary Authority boundary changes mean that the Cambridgeshire side of the point is now officially in the Unitary Authority of Peterborough, but the situation is otherwise unchanged.
In addition there are a few near misses. Near East Grinstead, the East Sussex-West Sussex-Surrey and East Sussex-Surrey-Kent tripoints are only a mile apart. Similarly the Staffordshire-Warwickshire-Leicestershire and Warwickshire-Leicestershire-Derbyshire tripoints are again around a mile apart.
And until 1965, the two tripoints formed by Gloucestershire, Oxfordshire, Wiltshire and Berkshire near Lechlade came very close to one another. ()
Near Evenlode in Gloucestershire, there is a "four-shire stone", but it lies at the Gloucestershire-Oxfordshire-Warwickshire tripoint, and around ten miles from Worcestershire.
[edit] Five or more regions
At subnational level, one can find even more than four divisions converging at a point.
Tertiary five point:
- Five counties in Florida meet within Lake Okeechobee[9]: Okeechobee, Martin, Palm Beach, Hendry, and Glades.
Cases of tertiary octopoints:
- Eight municipalities or towns in Albay, Philippines including Legazpi City meet on the crater of Mayon Volcano.
- Eight municipalities (Aura, Masku, Mynämäki, Nousiainen, Pöytyä, city of Turku, Vahto & Yläne) meet on Kuhankuono boundary mark[10] in the Kurjenrahka national park in Finland Proper.
[edit] References
This article was originally translated from the Dutch-language wiki article nl:Vierlandenpunt, as of 2006-06-20 [8], with the assistance of SystranBox online machine translation.
- ^ One could argue that, if one region lies on one side of a straight line border, and the other three are on the opposite side of this line, there are only three "corners" plus a straight line. However in geometry the straight line in this context would be considered to form a straight angle measuring 180°.
- ^ Brownlie, Ian, Ian R. Burns (1979). “Botswana-Zambia (Quadripoint issue)”, African Boundaries: A Legal and Diplomatic Encyclopaedia. London: C. Hurst & Co., 1098-1108. ISBN 0903983877.; summarized at African tripoints: Botswana-Namibia-Zambia by Michael Donner / Jesper Nielsen.
- ^ Akweenda, S. (1997-04-23). “VI: Quadripoint Theory”, International Law and the Protection of Namibia's Territorial Integrity. Netherlands: Martinus Nijhoff, 201-3. ISBN 9041104127.
- ^
- ^ One such map is at Image:Oceania ISO 3166-1.svg
- ^ Pacific Map, showing EEZ and 12 miles zone. SOPAC. Retrieved on 2006-12-10.
- ^ See The Baarle Enclaves website, including : overview with photograph of the H1-H2 quadripoint and Map including H1 and H2 enclaves
- ^ a b c Kallos, Aletheia (2006-06-08). an apparent nose2janontvb binational quadripoint. BoundaryPoint (Yahoo! Groups). Retrieved on 2006-06-20.
- ^ Counties of Florida map from U.S. Census Bureau.
- ^ Kuhankuono octopoint from National Land Survey of Finland map
[edit] See also
- Tripoint
- Tri-state area
- Land borders
- Four Corners (Canada)
- Four Corners (United States)
- Four Corners Monument
- Moresnet
- List of countries that border only one other country
- Borderless country
![[1]](http://commons.wikimedia.org/wiki/Image:Drilandenpunt.jpg){kind=link}
![[2]](http://nl.wikipedia.org/wiki/Afbeelding:Vierlandenpunt.jpg){kind=link}
