The Terdoppio is a river of

Piedmont Piedmont ( ; ; ) is one of the 20 regions of Italy, located in the northwest Italy, Northwest of the country. It borders the Liguria region to the south, the Lombardy and Emilia-Romagna regions to the east, and the Aosta Valley region to the ...

and

Lombardy The Lombardy Region (; ) is an administrative regions of Italy, region of Italy that covers ; it is located in northern Italy and has a population of about 10 million people, constituting more than one-sixth of Italy's population. Lombardy is ...

(northern

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

). It starts from the Piedmontese Prealps in the area between

Lake Orta Lake Orta (; Lombard and ) or Cusio (Lombard and ; ) is a lake in northern Italy, west of Lake Maggiore. It has been so named since the 16th century, but was previously called Lago di San Giulio, after Saint Julius (4th century), the patron s ...

and

Lake Maggiore Lake Maggiore (, ; ; ; ; literally 'greater lake') or Verbano (; ) is a large lake located on the south side of the Alps. It is the second largest lake in Italy and the largest in southern Switzerland. The lake and its shoreline are divided be ...

, and then crosses the

province of Novara The province of Novara () is a Provinces of Italy, province in the Piedmont region of Italy. Its capital is the city of Novara. In 1992, the new province of Verbano-Cusio-Ossola was created through the fusion of three geographical areas whic ...

. Near Cerano, it splits into two different streams: the first joins the

Ticino River The river Ticino ( , ; ; French and ; ) is the most important perennial left-bank tributary of the Po. It has given its name to the Swiss canton through which its upper portion flows. It is one of the four major rivers taking their source in t ...

, while the second flows through the

Lomellina The Lomellina ( or ) is a geographical and historical area in the Po Valley of northern Italy, located in south-western Lombardy between the Sesia, Po and Ticino rivers. It is one of three areal divisions of the Province of Pavia.

(

province of Pavia The province of Pavia () is a Provinces of Italy, province in the Lombardy region of Italy. Its capital is Pavia. , the province has a population of 548,722 inhabitants and an area of ; the town of Pavia has a population of 72,205. History T ...

) until it merges with the

Po River The Po ( , ) is the longest river in Italy. It flows eastward across northern Italy, starting from the Cottian Alps. The river's length is , or if the Maira (river), Maira, a right bank tributary, is included. The headwaters of the Po are forme ...

. The Terdoppio is long, with an average discharge of and a

drainage basin A drainage basin is an area of land in which all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, ...

of about .

References

Rivers of the Province of Novara Rivers of the Province of Pavia Rivers of Italy {{Italy-river-stub