Basin size 8,234 km (3,179 sq mi) Discharge 123 m³/s Mouth Po | Length 276 km Source Ligurian Alps Country Italy | |
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Main source Ligurian Alps, on the slopes of Monte Saccarello River mouth Po near Bassignana (AL) | ||
The Tanaro ([ˈtaːnaro]), known as Tanarus in ancient times and Tane or Tani in piedmontese language, is a 276-kilometre (171 mi) long river in northwestern Italy. The river begins in the Ligurian Alps, near the border with France, and is the most significant right-side tributary to the Po in terms of length, size of drainage basin (partly Alpine, partly Apennine), and discharge.
Contents
- Map of Fiume TC3A0naro Italy
- SourcesEdit
- CourseEdit
- TributariesEdit
- RegimeEdit
- Flood eventsEdit
- HistoryEdit
- References
Map of Fiume T%C3%A0naro, Italy
SourcesEdit
The Tanaro proper begins in Liguria at the confluence of two small streams, the sources of which are in Piedmont: the Tanarello and the Negrone.
The main source of the Tanarello is on the slopes of Monte Saccarello above Monesi, a village belonging to the commune of Triora. This mountain straddles the French département of Alpes-Maritimes, the Piedmontese province of Cuneo and the Ligurian province of Imperia and marks the juncture of the watersheds between three drainage basins: that of the Tanaro itself; that of the Roya (Italian Roia), which rises in France but enters the sea at Ventimiglia; and the Argentina, which flows into the Ligurian Sea at Taggia.
The sources of the Negrone are some 10 kilometres (6 mi) to the north, south of Punta Marguareis and very close to the French border.
CourseEdit
The Tanaro flows past the towns Ceva, Alba, Asti, and Alessandria before entering the Po near Bassignana in the Province of Alessandria. At its confluence with Po, it is longer by about 50 kilometres (31 mi) than the upper Po, a case similar to the famous Missouri tributary being longer than Mississippi in the United States.
TributariesEdit
The main tributaries to the Tanaro are the Stura di Demonte and the Borbore from the left and the Bormida and the Belbo from the right.
RegimeEdit
The flow is subject to a great deal of seasonal variation. Although the river has an Alpine origin, which is unique among the Po’s right-side tributaries, the Ligurian Alps are of an insufficient elevation and too close to the sea to allow for the formation of snow fields or glaciers large enough to provide a steady source of water during the summer. Furthermore, the Alpine zone forms only a part of the basin drained by the Tanaro. The seasonal regime of the river is therefore more typical of an Apennine stream, with a maximum discharge that can reach 1,700 cubic metres per second (60,000 cu ft/s), in spring and autumn and a very low rate of flow in the summer.
Flood eventsEdit
The river is highly prone to flooding. During the two hundred-year period between 1801 and 2001, sections of the Tanaro basin were affected by floods on 136 occasions, the most devastating being those in November 1994, when the whole of the river valley was affected by severe flooding, especially the town of Alessandria.
HistoryEdit
The left bank of the Tanaro River near Asti is the scene of the Battle of Pollentia on April 6, 402.