Somme (river)

Somme (river). The Somme is a major river in northern France, flowing for 245 kilometers from its source near Fonsommes in the Aisne department to its estuary in the English Channel at Saint-Valery-sur-Somme. It drains a basin of approximately 6,550 square kilometers, traversing the pastoral landscape of the Hauts-de-France region, most notably the historic province of Picardy. The river's gentle gradient and broad, marshy valley have profoundly shaped the region's ecology, human settlement, and history, including its infamous association with the First World War.

Geography

The Somme rises at an altitude of about 85 meters in the commune of Fonsommes, within the Île-de-France geological basin. Its course flows generally west-northwest, passing through the cities of Saint-Quentin, Péronne, and Amiens, the prefecture of the Somme (department). The river's valley is notably wide and flat, a characteristic feature of the Paris Basin, and is flanked by chalk plateaus. Below Amiens, the river begins to meander significantly through extensive peat bogs and marshes known as the Basin de la Somme before forming a straight, canalized channel for its final approach to the sea. Its estuary opens into the English Channel between the towns of Le Crotoy and Saint-Valery-sur-Somme.

Hydrology

The Somme is characterized by a very low gradient, averaging only 0.2%, which results in a slow-flowing, placid river prone to flooding and the formation of extensive wetlands. Its flow is regulated by a network of canals, most notably the Canal de la Somme, constructed in the 19th century to improve navigation and drainage. The river is fed by a number of tributaries, including the Avre, the Selle, the Noye, and the Ancre. The hydrological regime is pluvial oceanic, with high water typically occurring in winter and early spring. The unique hydrology supports the famous Hortillonnages, floating market gardens in Amiens, and the vast water meadows that define the region.

History

The Somme valley has been inhabited since prehistoric times, with significant archaeological sites like Saint-Acheul in Amiens giving its name to the Acheulean stone tool industry. During the Roman era, the river was known as *Samara* and the city of Samarobriva became a key settlement. In the Middle Ages, the valley was part of the County of Ponthieu and later integrated into the Kingdom of France. The river's strategic location made it a frequent battlefield, most catastrophically during the First World War, where the 1916 Battle of the Somme resulted in over one million casualties. Earlier conflicts include the Battle of Crécy in 1346 and the Battle of Agincourt in 1415, both part of the Hundred Years' War. The 1465 Battle of Montlhéry also involved forces from the region.

Ecology

The slow-moving Somme and its associated wetlands form one of the most important freshwater ecosystems in northern France. The river, its tributaries, and the extensive marshes of the Somme Bay estuary provide crucial habitats for a diverse range of flora and fauna. The area is a major stopover on the migratory route for birds such as the Eurasian spoonbill, Common shelduck, and Black-tailed godwit, leading to its designation as a Natura 2000 site and a Ramsar Wetland of International Importance. The waterways support populations of European otter, European beaver, and numerous fish species including pike, zander, and European eel. Conservation efforts are managed by organizations like the Syndicat Mixte Baie de Somme.

Economy

Historically, the Somme was a vital transport corridor, with commercial navigation boosted by the construction of the Canal de la Somme linking it to the Scheldt and Oise river systems. While its role for freight has declined, it remains important for tourism and recreational boating. The river valley supports significant agriculture, particularly market gardening and watercress farming in the Hortillonnages. The estuary region around Somme Bay is a major tourist destination, known for its scenic railways like the Chemin de Fer de la Baie de Somme, and the maritime resorts of Mers-les-Bains and Cayeux-sur-Mer. The river also supplies water for industrial and municipal use to urban centers like Amiens and Saint-Quentin.

Category:Rivers of France Category:Geography of Hauts-de-France Category:Landforms of Somme (department)