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Garonne

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The Garonne (/ɡəˈrɒn, ɡæˈrɒn/ gə-RON, garr-ON, French: [ɡaʁɔn] ⓘ; Catalan, Basque and Occitan: Garona, Occitan pronunciation: [ɡaˈɾunɔ]; Latin: Garumna[1][2] or Garunna) is a river that flows in southwest France and northern Spain. It flows from the central Spanish Pyrenees to the Gironde estuary at the French port of Bordeaux – a length of 529 km (329 mi),[3] of which 47 km (29 mi) is in Spain (Val d'Aran);[4] the total length extends to 602 km (374 mi) if one includes the Gironde estuary between the river and the sea. Its basin area is 56,000 km2 (22,000 sq mi),[4] which increases to 84,811 km2 (32,746 sq mi) if the Dordogne River, which flows from the east and joins the Garonne at Bec d'Ambès to form the Gironde estuary, is included.

Garonne
The Garonne at Bordeaux
Map of the Garonne River watershed
Native nameGarona (Occitan)
Location
CountriesFrance and Spain
Cities
Physical characteristics
SourcePyrenees
 • locationAlt Àneu, Catalonia, Spain
 • coordinates42°36′26″N 0°57′56″E / 42.607295°N 0.965424°E / 42.607295; 0.965424 (source Garonne)
 • elevation2,600 m (8,500 ft)
MouthGironde estuary, Atlantic Ocean
 • location
Bayon-sur-Gironde, Nouvelle-Aquitaine, France
 • coordinates
45°2′29″N 0°36′24″W / 45.04139°N 0.60667°W / 45.04139; -0.60667 (Gironde-Garonne)
 • elevation
0 m (0 ft)
Length529 km (329 mi)
Basin size56,000 km2 (22,000 sq mi), or including Dordogne: 84,811 km2 (32,746 sq mi)
Discharge 
 • average650 m3/s (23,000 cu ft/s)
Basin features
ProgressionGironde estuary→ Atlantic Ocean
Map

Umayyad and Aquitanian forces fought the Battle of the River Garonne in 732 beside the river near present-day Bordeaux.

Etymology

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The name derives from Garumna, a Latinized version of the Aquitanian name meaning "stony river" ("kar" relating to "stone" and "-ona" relating to "river").

Geography

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Sources

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150º 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 12 kilometres (7 mi) receives water from the Joèu (Pic Aneto).
 
The Main Lake of Saboredo and Pic de Saboredo, the head of the Garonne valley
 
The water from Barrancs and Escaleta ravines disappears into the ground at Forau de Aigualluts.
 
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 (42°42′34″N 0°56′43″E / 42.709494°N 0.945398°E / 42.709494; 0.945398), the Ratera-Saboredo cirque 42°36′26″N 0°57′56″E / 42.607295°N 0.965424°E / 42.607295; 0.965424), or the slopes of Pic Aneto (Salterillo-Barrancs ravine 42°38′59″N 0°40′06″E / 42.6498°N 0.6683°E / 42.6498; 0.6683 according to the season).

The Uelh deth Garona at 1,862 metres (6,109 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 2.5 kilometres (1.6 mi) to the bed of the main upper Garonne valley. The river runs for another 38 kilometres (24 mi) to the French border at Pont de Rei, 40.5 kilometres (25.2 mi) in total.

The Ratera-Saboredo cirque is the head of the upper Garonne valley, and its upper lake at 2,600 metres (8,500 ft) above sea level is the origin of the Ruda-Garona river, running for 16 kilometres (9.9 mi) to the confluence with the Beret-Garona brook and another 38 kilometres (24 mi) to the French border at Pont del Rei, 54 kilometres (34 mi) in total. At the confluence, the Ruda-Garona carries 2.6 cubic metres per second (92 cu ft/s) of water.[5][6] The Ratera-Saboredo cirque is considered by many researchers to be the origin of the Garonne.[7][8][9][10]

The third theory holds that the river rises on the slopes of Pic Aneto at 2,300 metres (7,500 ft) above sea level and flows by way of a sinkhole known as the Forau de Aigualluts (42°40′00″N 0°40′01″E / 42.6666°N 0.6669°E / 42.6666; 0.6669) 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.[11] This underground route was suggested by the geologist Ramond de Carbonnières in 1787 but there was no confirmation until 1931, when caver Norbert Casteret poured fluorescein dye into the flow and noted its emergence a few hours later 4 kilometres (2.5 mi) away at Uelhs deth Joèu ("Jove's eyes" 42°40′51″N 0°42′28″E / 42.68092°N 0.7077°E / 42.68092; 0.7077) in the Artiga de Lin on the other side of the mountain.[12][13][14] From Aigualluts to the confluence with the main river at the bed of the upper Garonne valley at 800 metres (2,600 ft) above sea level, the Joèu has run for 12.4 kilometres (7.7 mi) (16 kilometres more to get to the French border), carrying 2.16 cubic metres per second (76 cu ft/s) of water, whilst the main river is carrying 17.7 cubic metres per second (630 cu ft/s).[5][6][15]

Despite the lack of universal agreement on definition for determining a stream's 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.[16][17][18][19][20]

The Ratera-Saboredo cirque is the "most distant point (along watercourses from the river mouth) in the drainage basin from which water runs"[21][22] 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

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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, the Tarn, and the Lot. Just after Bordeaux, the Garonne meets the Dordogne at the Bec d'Ambès, forming the Gironde estuary, which after approximately 100 kilometres (62 mi) empties into the Atlantic Ocean. Other tributaries include the Save and the Gers.

The Garonne is one of the few rivers in the world that exhibit a tidal bore.[23][24][25] Surfers and jet skiers could ride the tidal bore at least as far as the village of Cambes, 120 kilometres (75 mi) from the Atlantic, and even further upstream to 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.[23] 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.[24][25][26]

European sea sturgeon conservation

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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 .[27] This species of sturgeon can reach a length of 6 m (20 ft), weigh up to 400 kg (880 lb) and reach an age of 100 years.[28] Previously found on most coasts of Europe, it has now become so rare that it breeds only in the Garonne river basin in France.[27] 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.[27]

 
The Garonne at Toulouse

Towns along the river

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Main tributaries

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Following the flow of the river, from source to mouth:

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The Garonne plays an important role in inland shipping. The river not only allows seagoing vessels to reach the port of Bordeaux but also forms part of the Canal des Deux Mers, linking the Mediterranean Sea and the Atlantic Ocean.

 
Seagoing vessels may navigate as far inland as Bordeaux on the Garonne.

From the ocean, ships pass through the Gironde estuary up to the mouth of the Garonne (to the right of the Dordogne when sailing upstream). Ships continue on the tidal river Garonne up to the Pont de Pierre (stone bridge) in Bordeaux. Inland vessels continue upstream to Castets-en-Dorthe, where the Canal de Garonne joins the river. Prior to the building of the Canal lateral à la Garonne, between 1838 and 1856, shallow-draught boats used the Garonne itself as far as Toulouse. However, navigation on the upper river was very uncertain, and this stretch of the river is no longer considered navigable. Instead the lateral canal takes boats through 53 locks to the town of Toulouse, where the canal meets the Canal du Midi.[29]

Hydrography

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The upstream part of the river, upstream from Toulouse depends primarily on snow and snow melt. The lower/downstream part is rain fed as well as its main tributaries.

The Garonne also feeds several channels/canals:

SANDRE assigns to the Garonne a hydrographic identity number 0 --- 00000 and the generic code O --- 000014,15.

Floods

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  • Flood of January 2022 in Toulouse.

A flood of the Garonne in 1930 broke the dike in Thivras (Marmande).

In Toulouse, the Garonne has been the cause of many floods, especially since its left bank is inhabited.

The earliest records of floods are from around 1177. It is also recorded to have flooded in 1220, 1258, 1430, 1523, 1536 and in 1589, 1608, 1658, 1673, 1675, 1709, 1712, 1727, 1750, 1772, 1788, 1804 and 1810. In 1772, the Garonne reached 8 meters 50.[31] In the recent centuries, in 1827, 1835, 1855 and 1856/7.

In Toulouse, in 1827, the water level of the Garonne rose four meters above the ordinary level and filled the arches of the Pont de Pierre and Pont Neuf.

In 1835, the Garonne rose to five meters above normal and 35 meters above the low water level and flowed through the four arcs of the Pont de Pierre.

Flood of the Garonne in 1835: 7,50 m at Toulouse Pont-Neuf

Flood of the Garonne in 1855: 7.25 m at Toulouse Pont-Neuf

Flood of the Garonne in 1875: 9,70 m to Toulouse Pont-Neuf (or 8m32 according to vigicrue).

Flood of the Garonne in 1879: 4,87 m at Toulouse Pont-Neuf

Flood of the Garonne in 1890: 3.30 m at Toulouse Pont-Neuf

Flood of the Garonne in 1900: 4,00 m in Toulouse Pont-Neuf

Flood of the Garonne in 1905: 4.24 m at Toulouse Pont-Neuf

Crete of 1927 in Aquitaine, particularly imposing after the confluence of the Garonne with the Lot (of which it remained raw reference), insignificant upstream18.

Flood of the Garonne in 1952: 4,57 m at Toulouse Pont-Neuf

Flood of the Garonne in 1977: 4,31 m in Toulouse Pont-Neuf

Flood of the Garonne in 2000: 4.38 m at Toulouse Pont-Neuf

Flood of the Garonne in 2004: 3,52 m at Toulouse Pont-Neuf

In 1777, the Garonne suffered an extraordinary flood to the point that the priest of Bourdelles took the trouble to retranscribe the event, at the end of the acts of the year, in the parish register of baptisms, marriages and deaths.

Future Water Resource Management

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The "Garonne 2050" project, initiated by the Adour-Garonne water agency in 2010, aims to address the future challenges facing the Garonne River basin regarding its water resources. With an anticipated surge of an additional 1 million inhabitants by 2050, the basin confronts a demographic challenge. The study aims to inform stakeholders and devise an adaptation strategy within the local master plan of water management and development (SDAGE), considering the impact of the predicted demographic shifts. [32] Central to the "Garonne 2050" study is its examination of the Garonne River basin's agricultural sector. Detailed insights into changes in irrigated agricultural areas, crop rotation, and farm numbers are essential for informing effective water management strategies. Notably, the allocation of water volume to agriculture highlights a delicate balance between sustaining local economic activities and the necessity for agricultural adaptation amid decreasing water availability.[33]

See also

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References

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  1. ^ Smith, William (1850). A new classical dictionary of Greek and Roman biography, mythology, and geography. London: John Murray. p. 492. OCLC 223027795.
  2. ^ Smith, William (1862). "GARUMNA". In Anthon, Charles (ed.). A New Classical Dictionary of Greek and Roman Biography, Mythology and Geography, partly based upon the Dictionary of Greek and Roman Biography and Mythology by William Smith [...]. Revised by Charles Anthon (revised ed.). New York: Harper (published 1895). p. 322. Retrieved 14 December 2019. GARUMNA (now Garonne), one of the chief rivers of Gaul, rises in the Pyrenees, flows northwest through Aquitania, and becomes a bay of the sea below Burdigala (now Bordeaux).
  3. ^ Sandre. "Fiche cours d'eau - La Garonne (O---0000)".
  4. ^ a b Le bassin versant de la Garonne, Syndicat Mixte d'Études & d'Aménagement de la Garonne
  5. ^ a b "3". oph.chebro.es. Archived from the original on 14 March 2012.
  6. ^ a b [1]
  7. ^ Salvador Rivas-Martínez (member of the Spanish Royal Academy of Sciences); Manuel Costa (Professor of the Universitat de Valencia) (1998). "Datos sobre la vegetación y bioclima del Valle de Arán". Acta Bot. Barcinon. 45: 473–499.
  8. ^ Soler i Santaló; La Vall d'Aran. Guía monográfica de la comarca; pág. 12. Barcelona, 1916.
  9. ^ 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.
  10. ^ Salvador, 1935-Rivas-Martínez; Manuel (Costa Talens), 1938-Costa (11 January 1998). "Boletín del Centro Excursionista de Cataluña". Acta Botanica Barcinonensia: 473–499.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  11. ^ Reynolds, Kev (2001). Walks and Climbs in the Pyrenees. Milnthorpe, England: Cicerone Press. p. 208. ISBN 978-1-85284-328-1.
  12. ^ Casteret, Norbert (1939). Ten Years Under the Earth. Mussey, Barrows (trans). London: J. M. Dent.
  13. ^ Mapa topogràfic de Catalunya 1:100 000 (Map) (1st ed.). Institut Cartogràfic de Catalunya. § 1: Pirineu occidental.
  14. ^ Lambert, Roger (1996). "A propos de la Garonne Supérieure". Géographie du cycle de l'eau (in French). Toulouse: Presses Universitaires du Mirail. p. 351. ISBN 978-2-85816-273-4. 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')
  15. ^ "VisorIGN". Archived from the original on 17 November 2010. Retrieved 11 January 2011.
  16. ^ "Largest Rivers in the United States" (PDF). United States Geological Survey. Retrieved 24 October 2009.
  17. ^ "National Geographic News @ nationalgeographic.com". Archived from the original on 13 April 2001.
  18. ^ "The True Utmost Reaches of the Missouri". Archived from the original on 18 January 2012. Retrieved 11 January 2011.
  19. ^ "IBGE - Instituto Brasileiro de Geografia e Estatística". Archived from the original on 28 September 2008. Retrieved 24 December 2019.
  20. ^ "Quest for the Missouri River Source, John LaRandeau, U.S. Army Corps of Engineers" (PDF). Archived from the original (PDF) on 2 June 2013. Retrieved 11 January 2011.
  21. ^ Instituto Geográfico Nacional; Ministerio de FOmento. "Visor cartográfico del Instituto Geográfico Nacional". Instituto Geográfico Nacional de España. Archived from the original on 5 December 2013. Retrieved 10 November 2012.
  22. ^ s - Géoportail, le portail des territoires et des citoyens. "IGN France Cartes Topographie". Retrieved 10 November 2012.
  23. ^ a b Chanson, H., Lubin, P., Simon, B., and Reungoat, D. (2010). Turbulence and Sediment Processes in the Tidal Bore of the Garonne River: First Observations. Hydraulic Model Report No. CH79/10, School of Civil Engineering, The University of Queensland, Brisbane, Australia, 97 pages. ISBN 978-1-74272-010-4.{{cite book}}: CS1 maint: multiple names: authors list (link)
  24. ^ a b Simon, B., Lubin, P., Reungoat, D., Chanson, H. (2011). Turbulence Measurements in the Garonne River Tidal Bore: First Observations. 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. pp. 1141–1148. ISBN 978-0-85825-868-6.{{cite book}}: CS1 maint: multiple names: authors list (link)
  25. ^ a b Chanson, Hubert; Reungoat, David; Simon, Bruno; Lubin, Pierre (December 2011). "High-frequency turbulence and suspended sediment concentration measurements in the Garonne River tidal bore". Estuarine, Coastal and Shelf Science. 95 (2–3): 298–306. Bibcode:2011ECSS...95..298C. CiteSeerX 10.1.1.692.2537. doi:10.1016/j.ecss.2011.09.012.
  26. ^ Reungoat, D., Chanson, H., Caplain, B. (2012). Field Measurements in the Tidal Bore of the Garonne River at Arcins (June 2012). ISBN 9781742720616. {{cite book}}: |journal= ignored (help)CS1 maint: multiple names: authors list (link)
  27. ^ a b c Gesner, J.; Williot, P.; Rochard, E.; Freyhof, J.; Kottelat, M. (2010). "Acipenser sturio". IUCN Red List of Threatened Species. 2010: e.T230A13040963. doi:10.2305/IUCN.UK.2010-1.RLTS.T230A13040963.en.
  28. ^ Froese, Rainer; Pauly, Daniel (eds.). "Acipenser sturio". FishBase. October 2005 version.
  29. ^ Rolt, L. T. C. (1973). From Sea to Sea: An Illustrated History of the Canal du Midi. Grenoble, France: Euromapping. pp. 19–40. ISBN 978-2-910185-02-2.
  30. ^ "Garonne Irrigation channels". Archived from the original on 4 December 2008. Retrieved 13 August 2018.
  31. ^ Astrié, Théophile (1875). Les drames de l'inondation à Toulouse / Théophile Astrié Éditeur : Éditeur : Librairie centrale (Toulouse) Date d'édition : 1875 gallica.bnf.fr/ark:/12148/bpt6k5778575j. Librairie centrale (Toulouse): Arnaud et Labat (Paris).
  32. ^ "Analysis n°68 - april 2014 The future of water resource availability in France: how is the agricultural sector taken into account in foresight studies?". Ministère de l'Agriculture et de la Souveraineté alimentaire (in French). Retrieved 7 May 2024.
  33. ^ Grusson, Youen; Anctil, François; Sauvage, Sabine; Sánchez Pérez, José Miguel (December 2018). "Coevolution of Hydrological Cycle Components under Climate Change: The Case of the Garonne River in France". Water. 10 (12): 1870. doi:10.3390/w10121870. ISSN 2073-4441.
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