Editing Garonne (section)

==Geography==

===Sources===
[[File:Garonne 5102.jpg|300px|thumb|left|Banks of the Garonne in [[Toulouse]]]]

The Garonne's headwaters are to be found in the [[Aran Valley]] in the Spanish [[Pyrenees]], though three different locations have been proposed as the true source: the ''Uelh deth Garona'' at Plan de Beret ({{Coord|42.709494|0.945398|display=inline|format=dms}}), the Ratera-Saboredo cirque {{Coord|42.607295|0.965424|display=inline|format=dms}}), or the slopes of [[Aneto|Pic Aneto]] (Salterillo-Barrancs ravine {{Coord|42.6498|0.6683|display=inline|format=dms}} according to the season).

The ''Uelh deth Garona'' at {{convert|1862|m|ft}} above [[sea level]] has been traditionally considered as the source of the Garonne. From this point a brook (called the ''Beret-Garona'') runs for {{convert|2.5|km|mi}} to the bed of the main [[Aran Valley|upper Garonne valley]]. The river runs for another {{convert|38|km|mi}} to the French border at ''[[Pont de Rei]]'', {{convert|40.5|km|mi}} in total.

The Ratera-Saboredo cirque is the head of the upper Garonne valley, and its upper lake at {{convert|2600|m|ft}} above sea level is the origin of the Ruda-Garona river, running for {{convert|16|km|mi}} to the confluence with the Beret-Garona brook and another {{convert|38|km|mi}} to the French border at ''Pont del Rei'', {{convert|54|km|mi}} in total. At the confluence, the Ruda-Garona carries {{convert|2.6|m3/s|cuft/s}} of water.<ref name="oph.chebro.es">{{cite web |url=http://oph.chebro.es/DOCUMENTACION/HidrogeologiaPirineos/3.2.ACUIFEROS.htm |website=oph.chebro.es |archive-url=https://web.archive.org/web/20120314231555/http://oph.chebro.es/DOCUMENTACION/HidrogeologiaPirineos/3.2.ACUIFEROS.htm |archive-date=14 March 2012 |title=3}}</ref><ref name="ReferenceA">[ftp://oph.chebro.es:2121/BulkDATA/DOCUMENTACION/DirectivaMarco/Garona/DocumPrevia%202008.pdf]</ref> The Ratera-Saboredo cirque is considered by many researchers to be the origin of the Garonne.<ref>{{cite journal |title=Datos sobre la vegetación y bioclima del Valle de Arán |url=http://www.raco.cat/index.php/ActaBotanica/article/view/59581/101176 |author1=Salvador Rivas-Martínez (member of the Spanish Royal Academy of Sciences) |author2=Manuel Costa (Professor of the Universitat de Valencia) |journal=Acta Bot. Barcinon |volume=45 |pages=473–499 |year=1998}}</ref><ref>Soler i Santaló; La Vall d'Aran. Guía monográfica de la comarca; pág. 12. Barcelona, 1916.</ref><ref name="Faura i Sans 1916">Faura i Sans (M.); Sobre hidrología subterránea en los Pirineos Centrales de Aragón y Cataluña. Bol. de la Real Soc. de Hist. Nat, vom. XVI, pgs. 353-354. Madrid, 1916.</ref><ref>{{cite journal| url = http://www.raco.cat/index.php/ActaBotanica/article/view/59581/101176| title = Boletín del Centro Excursionista de Cataluña| journal = Acta Botanica Barcinonensia| date = 11 January 1998| pages = 473–499| last1 = Salvador| first1 = 1935-Rivas-Martínez| last2 = Manuel (Costa Talens)| first2 = 1938-Costa}}</ref>

[[Image:SbrdoJavierSanchezPortero.jpg|300px|thumb|left|The Main Lake of Saboredo and Pic de Saboredo, the head of the Garonne valley]] 
The third theory holds that the river rises on the slopes of Pic Aneto at {{convert|2300|m|ft}} above sea level and flows by way of a [[sinkhole]] known as the ''[[Forau de Aigualluts]]'' ({{Coord|42.6666|0.6669|display=inline|format=dms}}) through the [[limestone]] of the Tuca Blanca de Pomèro and a resurgence in the Val dera Artiga above the Aran Valley in the Spanish Pyrenees.<ref>{{cite book|last=Reynolds|first=Kev|title=Walks and Climbs in the Pyrenees|publisher=Cicerone Press|location=Milnthorpe, England|year=2001|pages=208|isbn=978-1-85284-328-1}}</ref> This underground route was suggested by the geologist [[Louis Ramond de Carbonnières|Ramond de Carbonnières]] in 1787 but there was no confirmation until 1931, when [[Caving|caver]] [[Norbert Casteret]] poured [[fluorescein]] dye into the flow and noted its emergence a few hours later {{convert|4|km}} away at ''Uelhs deth Joèu'' ("Jove's eyes" {{Coord|42.68092|0.7077|display=inline|format=dms}}) in the Artiga de Lin on the other side of the mountain.<ref>{{cite book|last=Casteret|first=Norbert|others=[[Henry Hay (writer)|Mussey, Barrows]] (trans)|title=Ten Years Under the Earth|publisher=J. M. Dent|location=London|year=1939}}</ref><ref>{{cite map
  |publisher = Institut Cartogràfic de Catalunya
  |title = Mapa topogràfic de Catalunya 1:100 000
  |edition = 1st
  |section = 1: Pirineu occidental
  }}
</ref><ref>{{cite book|last=Lambert|first=Roger|title=Géographie du cycle de l'eau|year=1996|publisher=Presses Universitaires du Mirail|location=Toulouse|language=fr|isbn=978-2-85816-273-4|page=351|chapter=A propos de la Garonne Supérieure|quote=prouvant péremptoirement que la Garonne a sa vrai source et la plus importante dans les Monts Maudits, sur le versant Sud des Pyrénées ('proving conclusively that the Garonne has its true source, and the most important, in the Monts Maudits, on the southern slopes of the Pyrenees')}}</ref> From Aigualluts to the confluence with the main river at the bed of the upper Garonne valley at {{convert|800|m|ft}} above sea level, the Joèu has run for {{convert|12.4|km|mi}} (16 kilometres more to get to the French border), carrying {{convert|2.16|m3/s|cuft/s}} of water, whilst the main river is carrying {{convert|17.7|m3/s|cuft/s}}.<ref name="oph.chebro.es"/><ref name="ReferenceA"/><ref>{{Cite web |url=http://www.ign.es/iberpix/visoriberpix/visorign.html |title=VisorIGN |access-date=11 January 2011 |archive-url=https://web.archive.org/web/20101117160824/http://www.ign.es/iberpix/visoriberpix/visorign.html |archive-date=17 November 2010 |url-status=dead }}</ref>

[[Image:Benasque - Aigualluts - Cascada 03.jpg|300px|thumb|right|The water from Barrancs and Escaleta ravines disappears into the ground at ''[[Forau de Aigualluts]]''.]]
Despite the lack of universal agreement on definition for determining a stream's [[Source (hydrology)|source]], the [[United States Geological Survey]], the [[National Geographic Society]] and the [[Smithsonian Institution]] agree that a stream's source should be considered as the most distant point (along watercourses from the [[river mouth]]) in the [[drainage basin]] from which water runs.<ref name=usgs-largest>{{cite web |title= Largest Rivers in the United States |publisher= [[United States Geological Survey]] |url= http://pubs.usgs.gov/of/1987/ofr87-242/pdf/ofr87242.pdf |access-date= 24 October 2009}}</ref><ref>{{cite web| url = http://news.nationalgeographic.com/news/2000/12/1221amazon.html| archive-url = https://web.archive.org/web/20010413002040/http://news.nationalgeographic.com/news/2000/12/1221amazon.html| url-status = dead| archive-date = 13 April 2001| title = National Geographic News @ nationalgeographic.com<!-- Bot generated title -->}}</ref><ref name="fwp.mt.gov">{{cite web| url = http://fwp.mt.gov/mtoutdoors/HTML/articles/2005/MissouriSource.htm| title = The True Utmost Reaches of the Missouri<!-- Bot generated title -->| access-date = 11 January 2011| archive-date = 18 January 2012| archive-url = https://web.archive.org/web/20120118010715/http://fwp.mt.gov/mtoutdoors/HTML/articles/2005/MissouriSource.htm| url-status = dead}}</ref><ref>{{cite web |url=http://www.ibge.gov.br/english/presidencia/noticias/noticia_visualiza.php?id_noticia=885&id_pagina=1/ |title=IBGE - Instituto Brasileiro de Geografia e Estatística |archive-url=https://web.archive.org/web/20080928094531/http://www.ibge.gov.br/english/presidencia/noticias/noticia_visualiza.php?id_noticia=885&id_pagina=1%2F |archive-date=28 September 2008 |access-date=24 December 2019 |url-status=live }}</ref><ref>{{Cite web |url=http://infolink.cr.usgs.gov/events/Conferences/mrc04/04Program.pdf |title=Quest for the Missouri River Source, John LaRandeau, U.S. Army Corps of Engineers |access-date=11 January 2011 |archive-url=https://web.archive.org/web/20130602031213/http://infolink.cr.usgs.gov/events/Conferences/mrc04/04Program.pdf |archive-date=2 June 2013 |url-status=dead }}</ref>

The Ratera-Saboredo cirque is the "most distant point (along watercourses from the river mouth) in the drainage basin from which water runs"<ref>{{cite web|title=Visor cartográfico del Instituto Geográfico Nacional|url=http://www2.ign.es/iberpix/visoriberpix/visorign.html?x=318460.9166&y=4727915.4788&zone=31&r=9952&visible=MAPA_MTN200;|publisher=Instituto Geográfico Nacional de España|access-date=10 November 2012|author1=Instituto Geográfico Nacional|author2=Ministerio de FOmento|archive-date=5 December 2013|archive-url=https://web.archive.org/web/20131205075735/http://www2.ign.es/iberpix/visoriberpix/visorign.html?x=318460.9166&y=4727915.4788&zone=31&r=9952&visible=MAPA_MTN200;|url-status=dead}}</ref><ref name="s - Géoportail, le portail des territoires et des citoyens">{{cite web|last=s - Géoportail, le portail des territoires et des citoyens|title=IGN France Cartes Topographie|url=http://www.geoportail.gouv.fr/accueil|access-date=10 November 2012}}</ref> and the source of the Garonne, according to the United States Geological Survey, the National Geographic Society and the Smithsonian Institution convention on determining a stream's source.

===Course===
The Garonne follows the Aran Valley northwards into France, flowing via [[Toulouse]] and [[Agen]] towards [[Bordeaux]], where it meets the [[Gironde estuary]]. The Gironde flows into the [[Atlantic Ocean]] ([[Bay of Biscay]]). Along its course, the Garonne is joined by three other major rivers: the [[Ariège (river)|Ariège]], the [[Tarn (river)|Tarn]], and the [[Lot (river)|Lot]]. Just after Bordeaux, the Garonne meets the [[Dordogne (river)|Dordogne]] at the [[Bec d'Ambès]], forming the Gironde estuary, which after approximately {{convert|100|km|mi|}} empties into the Atlantic Ocean. Other tributaries include the [[Save (Garonne)|Save]] and the [[Gers (river)|Gers]].

[[File:Valledelgarona.jpg|600px|thumb|centre|150° Panorama of the Aran Valley from the Beret Plateau, showing the Ruda-Garona and Beret-Garona confluence. In [[Vielha]] the Garonne turns westward (out of sight), and after {{convert|12|km|mi|0}} receives water from the Joèu (Pic Aneto).]]
The Garonne is one of the few rivers in the world that exhibit a [[tidal bore]].<ref name="Chanson_etal2010">{{cite book|author=[[Hubert Chanson|Chanson, H.]], Lubin, P., Simon, B., and Reungoat, D. |title= Turbulence and Sediment Processes in the Tidal Bore of the Garonne River: First Observations |url= http://espace.library.uq.edu.au/view/UQ:219711 |publisher=Hydraulic Model Report No. CH79/10, School of Civil Engineering, The University of Queensland, Brisbane, Australia, 97 pages|year=2010 |isbn= 978-1-74272-010-4}}</ref><ref name="Simon_et_al2011">{{cite book|author=Simon, B., Lubin, P., Reungoat, D., [[Hubert Chanson|Chanson, H.]] |title= Turbulence Measurements in the Garonne River Tidal Bore: First Observations |url= http://espace.library.uq.edu.au/view/UQ:243200 |publisher=Proc. 34th IAHR World Congress, Brisbane, Australia, 26 June – 1 July, Engineers Australia Publication, Eric Valentine, Colin Apelt, James Ball, [[Hubert Chanson]], Ron Cox, Rob Ettema, George Kuczera, Martin Lambert, Bruce Melville and Jane Sargison Editors |pages=1141–1148 |year=2011 |isbn= 978-0-85825-868-6}}</ref><ref name="Chanson_etal2012">{{cite journal|last1=Chanson|first1=Hubert|author-link1=Hubert Chanson|last2=Reungoat|first2=David|last3=Simon|first3=Bruno|last4=Lubin|first4=Pierre|title=High-frequency turbulence and suspended sediment concentration measurements in the Garonne River tidal bore|journal=[[Estuarine, Coastal and Shelf Science]]|date=December 2011|volume=95|issue=2–3|pages=298–306|bibcode=2011ECSS...95..298C|doi=10.1016/j.ecss.2011.09.012|citeseerx=10.1.1.692.2537}}</ref> Surfers and jet skiers could ride the tidal bore at least as far as the village of [[Cambes, Gironde|Cambes]], {{convert|120|km|mi}} from the Atlantic, and even further upstream to [[Cadillac, Gironde|Cadillac]], although the tidal bore appears and disappears in response to changes in the channel bathymetry. In 2010 and 2012, some detailed field studies were conducted in the Garonne's Arcins channel between [[Arcins Island]] and the right bank close to Lastrene township.<ref name="Chanson_etal2010" /> A striking feature of the field data sets was the large and rapid fluctuations in turbulent velocities and turbulent stresses during the tidal bore and flood flow.<ref name="Simon_et_al2011" /><ref name="Chanson_etal2012" /><ref name="Chanson_etal2012b">{{cite book|author=Reungoat, D., [[Hubert Chanson|Chanson, H.]], Caplain, B. |title= Field Measurements in the Tidal Bore of the Garonne River at Arcins (June 2012) |journal=Hydraulic Model Report No. CH89/12, School of Civil Engineering, the University of Queensland, Brisbane, Australia, 121 Pages |year=2012 |isbn= 9781742720616 |url=http://espace.library.uq.edu.au/view/UQ:284154}}</ref>

===European sea sturgeon conservation===
[[File:Acipenser sturio.jpg|thumb|left|The [[European sea sturgeon]] (''Acipenser sturio'')]]
The [[European sea sturgeon]] (Acipenser sturio), also known as the Atlantic sturgeon or common sturgeon, is now a [[Critically Endangered species]] '''(IUCN) status'''[[File:Status iucn CR icon.svg|20px]].<ref name=IUCN>{{Cite iucn | author = Gesner, J. | author2 = Williot, P. | author3 = Rochard, E. | author4 = Freyhof, J. | author5 = Kottelat, M. | title = ''Acipenser sturio'' | volume = 2010 | page = e.T230A13040963 | date = 2010 | doi = 10.2305/IUCN.UK.2010-1.RLTS.T230A13040963.en }}</ref> This species of sturgeon can reach a length of {{convert|6|m|abbr=on}}, weigh up to {{convert|400|kg|abbr=on}} and reach an age of 100 years.<ref name=Fishbase>{{FishBase_species|genus=Acipenser|species=sturio|year=2005|month=10}}</ref> Previously found on most coasts of Europe, it has now become so rare that it breeds only in the Garonne river basin in France.<ref name=IUCN /> Conservation projects are under way to save this fish from [[extinction]] via [[species reintroduction]] from [[aquaculture]], with the first releases having been made in 1995.<ref name=IUCN />

[[File:Garonne river.jpg|thumb|left|400px|The Garonne at [[Toulouse]]]]

===Towns along the river===
* [[Aran Valley]] (Spain): [[Vielha]],  [[Bossòst]]
* [[Haute-Garonne]] (31): [[Saint-Gaudens, Haute-Garonne|Saint-Gaudens]], [[Muret]], [[Toulouse]]
* [[Tarn-et-Garonne]] (82): [[Castelsarrasin]]
* [[Lot-et-Garonne]] (47): [[Agen]], [[Marmande]], [[Aiguillon, Lot-et-Garonne|Aiguillon]]
* [[Gironde]] (33): [[Langon, Gironde|Langon]], [[Bordeaux]]