Loire - Geography

Geography

The source of the river lies in the eastern Massif Central, in springs to the south side of Mont Gerbier de Jonc at 44°50′38″N 4°13′12″E / 44.84389°N 4.22°E / 44.84389; 4.22. This lies in the north-eastern part of the southern Cévennes highlands, in the Ardèche commune of Sainte-Eulalie of southeastern France. It is originally a mere trickle of water located at 1,408 m (4,619 ft) above sea level. The presence of a groundwater under Mont Gerbier de Jonc gives rise to multiple sources, three of them located at the foot of Mount have been highlighted as river sources. The three streams converge to form the Loire, which descends the valley south of Mount through the village of Sainte-Eulalie itself.

The Loire River changed its course, due to tectonic deformations, from the original outfall into the English Channel to its new outfall into the Atlantic Ocean thereby creating the presently seen narrow terrain of gorges, the Loire Valley with alluvium formations and the long stretch of beaches along the Atlantic Ocean. The river can be divided into three main zones; the Upper Loire which is the area from the source to the confluence with the Allier, the middle Loire Valley which is the area from the Allier to the confluence with the Maine, about 280 km (170 mi), and the Lower Loire which is the area from Maine to the estuary. In the upper basin the river flows through a narrow, incised valley, marked by gorges and forests on the edges and a distinct low population. In the intermediate section, the alluvial plain broadens and the river meanders and forks into multi-channels. River flow is particularly high in the river area near Roanne and Vichy up to the confluence with the Allier. In the middle section of the river in the Loire Valley, numerous dikes built between the 12th and 19th century exist, providing mitigation against flooding. In this section the river is relatively straight, except for the area near Orléans and numerous sand banks and islands exist. The lower course of the river is characterized by wetlands and fens, which are of major importance to conservationists given that they from unique habitats for migratory birds.

The Loire flows roughly northward through Roanne and Nevers to Orléans and thereafter westward through Tours to Nantes, where it forms an estuary. It flows into the Atlantic Ocean at 47°16′44″N 2°10′19″W / 47.27889°N 2.17194°W / 47.27889; -2.17194 between Saint-Nazaire and Saint-Brevin-les-Pins, connected by a bridge over the river near its mouth. Several départements of France were named after the Loire. The Loire flows through the following départements and towns: Ardèche, Haute-Loire: Le Puy-en-Velay, Loire: Feurs, Roanne, Saône-et-Loire: Digoin, Allier, Nièvre: Decize, Nevers, La Charité-sur-Loire, Cosne-Cours-sur-Loire, Cher: Sancerre, Loiret: Briare, Gien, Orléans, Loir-et-Cher: Blois, Indre-et-Loire: Amboise, Tours, Maine-et-Loire: Saumur, Loire-Atlantique: Ancenis, Nantes, Saint-Nazaire.

The Loire Valley in the Loire River basin, is a 300 km (190 mi) stretch in the western reach of the river starting with Orléans and terminating at Nantes, 56 km (35 mi) short of the Loire estuary and the Atlantic Ocean. The tidal stretch of the river extends to a length of 60 km (37 mi) and a width of 3 km (1.9 mi), which has oil refineries, the port of St-Nazaire and 40,000 hectares (99,000 acres) of wetland whose formation is dated to 7500 BC (caused by inundation by sea waters on the northern bank of the estuary), and the beaches of Le Croisic and La Baule along the coast line.