page_title: Po Valley
section_title: Geography
hierarchical_section_title: Po Valley / Geography
caption_attribution_description: Italiano: Panorama delle risaie del basso vercellese con il fiume Po dai primi rilievi del Monferrato Casalese. In secondo piano l'abitato di Fontanetto Po (VC)
context_page_description: The Po Valley, Po Plain, Plain of the Po, or Padan Plain is a major geographical feature of Northern Italy. It extends approximately 650 km in an east-west direction, with an area of 46,000 km² including its Venetic extension not actually related to the Po river basin; it runs from the Western Alps to the Adriatic Sea. The flatlands of Veneto and Friuli are often considered apart since they do not drain into the Po, but they effectively combine into an unbroken plain.
  The plain is the surface of an in-filled system of ancient canyons extending from the Apennines in the south to the Alps in the north, including the northern Adriatic. In addition to the Po and its affluents, the contemporary surface may be considered to include the Savio, Lamone and Reno to the south, and the Adige, Brenta, Piave and Tagliamento of the Venetian Plain to the north, among the many streams that empty into the north Adriatic from the west and north.
  Geo-political definitions of the valley depend on the defining authority.
context_section_description: The Po Valley is often regarded as a syncline, or dip in the crust due to compression at the edges. Regardless of whether this concept accurately describes its geology, the valley is manifestly a sediment-filled trough, or virtual syncline, continuous with the deeps of the Adriatic Sea. The surface terrain is therefore divided into two overall types of landform: the plain, or flat surface of the fill, and the anticline at the edges, taking the form of hilly country in which the outcrops of the original rock are visible along with alluvial fans formed from the outwash of the more severe anticlinal terrain; that is, the Apennines and the Alps.
  The valley is broadly divided into an upper, drier part, often not particularly suited for agriculture, and a lower, very fertile, and well irrigated section, known in Lombardy and western Emilia as la Bassa, "the low (plain)". The upper areas of the Po valley take local names which reflect in their meanings their being modestly suited for farming. So we have the Piedmontese vaude and baragge, the Lombard brughiere and Groane, or, exiting from the Po valley proper, the Friulian magredi, areas remote from easily reachable water tables and covered with dense woods or dry soils.
  This specific meaning for "lower plain" derive from a geologic feature called the fontanili ("spring") line or zone, a band of springs around the Val Po, heaviest on the north, on the lowermost slopes of the anticline. It varies from a few kilometres to as much as 50 km (30 miles) wide. The fontanili line is the outcrop, or intersection, of the anticline's water table with the surface at the edge of the bassa. The rock above the line is porous. Surface water in the intermittent streams of the mountains tends to disappear below ground only to spring out again in the spring zone. The spring zone is often called "the middle valley."
  Surface runoff water (the Po and its affluents) is not of much value to the valley's dense population for drinking and other immediate uses, being unreliable, often destructive and heavily polluted by sewage and fertilizers. Its main anthropic value is for hydro-electric power, irrigation and industrial transport. The cost of purifying it for human consumption makes that process less feasible. The fresh drinking water comes from hundreds of thousands of wells concentrated especially in the fontanili zone. The major settlements therefore are also in that zone, which has become the centre of economic development and industry in Italy, and now is an almost continuous megalopolis stretching from Turin to Trieste.
  The bassa Padana was settled and farmed earliest, in Etruscan and Roman times. After the collapse of the Roman Empire (5th century AD), lack of maintenance of the irrigation systems associated with a cooling climate phase (i.e. the so-called Migration Period or The Dark Age Cold Period) led to the progressive waterlogging of the Po Valley and the natural depressions on the right side of the Po River turned in vast swamp basins. The waterlogging process of the area continued until the 10th century influencing the human sustenance and settling practices. According to historical-archaeological data, indeed, the wetlands were exploited for fishing as well as for transport by boat while the early medieval sites settled on the fluvial ridges, in topographically higher and strategic position in the surrounding swampy meadows.
  The Po Valley has been completely turned to agriculture since the Middle Ages, when efforts from monastic orders, feudal lords and free communes converged. The older and smaller cities deriving from ancient times are still located there.
  According to historical maps and documents the land reclamation of the  Po Valley reached its peak during the Renaissance (15th–16th centuries) and continued in the Modern Age (17th–18th centuries), with the last marsh areas only being reclaimed in the 20th century: channels and drainage system are still active and allow the Po Valley to be drained and be cultivatable.
caption: Rice fields in the province of Vercelli, eastern Piedmont.
exif: {}