Trebbia

This article is about the river in north Italy. For other uses, see Trebia.

Trebbia
Physical characteristics
Mouth	Po river, right bank, just upstream from Piacenza
• elevation	61 m (200 ft)
Length	118 km (73 mi)

The Trebbia (stressed Trèbbia; Template:Lang-la) is a river predominantly of Liguria and Emilia Romagna in northern Italy. It is one of the four main right-bank tributaries of the river Po, the other three being the Tanaro, the Secchia and the Panaro. The 1,150 km² (444 square miles) drainage basin is divided between Emilia Romagna (770 km², 300 mi²), Liguria (349 km², 135 mi²) and Lombardy (31 km², 12 mi²). Its principal tributaries are the torrents Aveto and Perino (from the right) and the torrent Boreca (from the left).

Its source, the Trebbia river spring, is in the Ligurian Apennines on the south slopes of Monte Prelà, to the south of Monte Antola in the comune of Torriglia, Province of Genoa. Monte Prelà, 1,407 m (4,616 ft) high, is part of the Antola massif.

The spring is not on the peak but is at roughly 800 m (2,600 ft). Across a small ridge to the west, on which sits Torriglia, and slightly further downslope is the source of the Scrivia river. Over a ridge to the northeast is the Brugneto reservoir, water supply for Genoa. The reservoir was created in 1959 by damming Brugneto stream, which formerly joined its waters to the Trebbia, but now only does so when the reservoir is full. A ridge running north from Prelà connects to Monte Druso, then to Monte Cremado, and finally to Monte Antola at 1,597 m (5,240 ft). From its peak on a clear day can be seen Genoa, Corsica, the Tuscan Archipelago and the Alps.

From its source the river flows towards north-east for 118 km (73 mi) until it reaches the Po just to the west of Piacenza.

The Ponte Gobbo (‘hunchback bridge’) or Ponte Vecchio (‘old bridge’) is a Devil’s Bridge of 280 metres (920 ft), which spans the river at Bobbio.

The Trebbia valley in July, a few kilometres upstream from Bobbio.

The main centres through which the trebbia flows before Piacenza are Ottone, Marsaglia (in the comune of Corte Brugnatella), Bobbio, Perino (a frazione of Coli), Travo and Rivergaro. Between its source and Bobbio the river flows through a valley (the Val Trebbia) of great natural beauty, which attracts tourists for walking as well as for aquatic sports. The river valley then widens before merging with the Pianura Padana beyond Rivergaro. Nearly the whole course of the river is paralleled by the Strada statale della Val Trebbia, highway SS45, running between Piacenza and Genoa. It encounters the river at Rivergaro and winds with it through the mountains, breaking away just below the source to bend southwest over the ridges to Genoa.

Ecology

Flora

The following trees are predominant in the forests of Val Trebbia: Fagus silvatica at 800 m (2,600 ft) to 1,500 m (4,900 ft); over 1500 m: Sorbus aucuparia, Sorbus aria, Laburnum anagyroides, Acer pseudoplatanus, Abies alba, Larix decidua, Alnus incana, Populus tremula; below 1,000 m (3,300 ft): Quercus cerris, Quercus sessiflora, Quercus pubescens, Ostrya carpinifolia, Carpinus betulus, Fraxinus ornus, Acer campestre, Ulmus campestris, Populus alba, Populus canescens, Alnus glutinosa, Prunus avium, Pirus communis, Malus communis, Corylus avellana; below 800 m (2,600 ft):Castanea sativa.

Fauna

The Val Trebbia is within the endemic range of Moltoni's Warbler, a subspecies of Sylvia cantillans better known in the western Mediterranean islands. The birds forage for insects in mixed shrubland of varying heights and both broad-leaved and coniferous composition.

Geologic history

The northern Apennines are a belt of northeast-southwest mountains on the coast of northwest Italy folded by transverse thrusting from sedimentary rock. The streams draining it run primarily in a northeastern direction perpendicular to the line of the folds and project into the Po river an average of 50 km (31 mi) from the source. The eroded landscape of the north Apennines covers about 2,800 km² (1,100 sq mi).

For much of their lengths, these heavily braided streams run through montane terrain that is minimally developed, is known for its wildlife, and remains in a pristine state. The sediment eroded from the mountains is deposited in alluvial fans and terraces in the Po valley, which is heavily populated and in ancient times flooded regularly. Diking has prevented much of the flooding but now due to confinement of deposition within the stream beds significant lengths of stream run entirely above ground, in places as high as the rooftops. This is a development of the previous thousand years.

Val Trebbia is covered with a blanket of rich soil reddish or brown in color from hematite an average of 4 m (13 ft) deep. It consists of loess deposited in layers during periods of glacial maxima beginning about 400000 years ago in the Middle Pleistocene. The loess initially accumulated on gravelled terraces deriving from native rock.

Cultural history

Judging from the archaeological evidence, the Trebbia valley has been continuously occupied since the end of the Acheulian in the Paleolithic, about 150000 years ago. In the Mesolithic various summer camps for high-altitude hunting were located in the valley. Neolithic cultures were at first diverse (4500 BC). Later in the Neolithic, at about 4000 BC, the Square-mouthed pottery culture began to prevail; at about 3000 BC, the Chassey-Lagozza culture of the Chalcolithic. The Bronze Age population resided in settlements located at positions with natural defenses. Etruscan elements began in the Iron Age, about the 5th century BC. Celtic artifacts immediately preceded the Roman presence.

Along its eastern banks in 218 BC was fought one of the battles of the Second Punic War: the Battle of Trebbia, where Hannibal defeated a Roman consular army.

The name of the river is first known from Livy, who wrote in the early Roman Empire, but used materials dating to the Roman Republic. Which people first assigned it and during which period remains unclear. Without knowing the probable language the few etymologies are highly speculative.

Gallery

Images of the Trebbia

• 
  At Rivergaro
• 
  At Bobbio
• 
  At Gorreto

External links

• "Trebbia". The American Heritage Dictionary of the English Language (Fourth ed.). 2000.
• "trebia". Merriam-Webster's Online Dictionary.
• Charlton T. Lewis (1879). "Trĕbĭa". A Latin Dictionary. Oxford: Clarendon Press. {{cite encyclopedia}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)