The Glomma or Glåma is

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...

's longest and most voluminous

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

. With a total length of , it has 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, ...

that covers 13% of Norway's surface area, all in the southern part of the country.

Geography

At its fullest length, the river runs from the lake Aursunden in Røros Municipality in

Trøndelag Trøndelag (; or is a county and coextensive with the Trøndelag region (also known as ''Midt-Norge'' or ''Midt-Noreg,'' "Mid-Norway") in the central part of Norway. It was created in 1687, then named Trondhjem County (); in 1804 the county was ...

county and runs into the

Oslofjord The Oslofjord (, ; ) is an inlet in southeastern Norway. The fjord begins at the small village of Bonn in Frogn, Frogn Municipality and stretching northwards to the city of Oslo, and then curving to the east and then south again. It then flows s ...

at the town of

Fredrikstad Fredrikstad (; previously ''Frederiksstad''; literally "Fredrik's Town") is a List of cities in Norway, city and Municipalities of Norway, municipality in Østfold Counties of Norway, county, Norway. The administrative centre of the municipal ...

in Fredrikstad Municipality in

Østfold Østfold () is a county in Eastern Norway, which from 1 January 2020 to 31 December 2023 was part of Viken. Østfold borders Akershus and southwestern Sweden (Västra Götaland County and Värmland), while Buskerud and Vestfold are on the other ...

county. Major tributaries include the Vorma River, which drains Lake Mjøsa, joining the Glomma River at Årnes in Nes Municipality. The large river Lågen flows into Lake Mjøsa, draining the large Gudbrandsdalen valley and significantly increasing the Glomma's flow. Because it flows through some of the richest forest districts, it has historically been Norway's leading log-floating river. The combination of raw materials, water power, and easy transport has over the centuries encouraged industry along the Glomma. Some of the country's largest manufacturing and processing concerns are found around its mouth, where supplies of timber and

hydropower Hydropower (from Ancient Greek -, "water"), also known as water power or water energy, is the use of falling or fast-running water to Electricity generation, produce electricity or to power machines. This is achieved by energy transformation, ...

have been backed by excellent port facilities. The upper limit of the Glomma valley farms is variable, but typically runs about in

Østerdalen Østerdalen () is a valley and Districts of Norway, traditional district in Innlandet county, in Eastern Norway. This area typically is described as the large Glåma river valley as well as all its tributary valleys. Østerdalen is often subdivide ...

, slightly lower than in the Gudbrandsdalen, which reflects the colder climate. The treeline, with a light birch forest, rises to about in Østerdalen. North of Røros, the forested areas are only on the valley floor. The upper river valleys of Norwegian rivers have distinctive names which are vestiges of earlier cultural distinctions such as building styles, traditional clothing or bunad and domestic crafts. The upper valley of the Glomma is the

(). Upon entering Lake Øyeren at Fetsund, the Glomma has formed Europe's largest inland delta which reaches the opposite side of the lake, across its short axis. Some of the vast amount of

silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension (chemistry), suspension with water. Silt usually ...

that the Glomma deposits in Lake Øyeren is extracted to manufacture LECA building blocks widely used for in the construction of foundations in Norway.

Name

The form ''Glomma'' is used in

and

Akershus Akershus () is a county in Norway, with Oslo as its administrative centre, though Oslo is not located within Akershus. Akershus has been a region in Eastern Norway with Oslo as its main city since the Middle Ages, and is named after the Akers ...

counties, while in

Innlandet Innlandet is a Counties of Norway, county in Norway. It was created on 1 January 2020 with the merger of the old counties of Oppland and Hedmark (Jevnaker Municipality and Lunner Municipality were transferred to the neighboring county of Viken ( ...

and

counties the river is called (and written) ''Glåma''. An older form was ''Glaumr''; another, in

Old Norse Old Norse, also referred to as Old Nordic or Old Scandinavian, was a stage of development of North Germanic languages, North Germanic dialects before their final divergence into separate Nordic languages. Old Norse was spoken by inhabitants ...

, was ''Raumelfr'', meaning a "loud noise" or "thunder" + "river".Tolkien, Christopher (trans.),
The Saga of King Heidrek the Wise
' (London: Nelson, 1960), p. 67 fn. 4. Several places are named after the river, for instance Glåmdal and Glåmos.

References

External links

* {{Authority control Rivers of Akershus Rivers of Innlandet Rivers of Trøndelag Ramsar sites in Norway Rivers of Norway Rivers of Østfold

Geography

Name

See also

References

External links