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Ob

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The Ob is a major river located in western Siberia, Russia. It is the westernmost of the three great Siberian rivers that flow into the Arctic Ocean. The other two great rivers in this region are the Yenisei and the Lena. When the Ob joins with its tributary, the Irtysh, they form a massive river system. This system is the seventh-longest in the world.

Ob river
Ob river

The river plays a vital role in the geography and economy of the region.

The river begins at the confluence of the Biya and Katun rivers. Both of these streams originate in the Altai Mountains. These mountains eventually transition into the Ob Plateau. The Ob itself flows in a north-westward direction before turning northward. After traveling through the landscape, it winds eastwards into the Gulf of Ob. This gulf is a bay of the Kara Sea. It is also recognized as the longest estuary in the world.

The Ob system is fed by many different tributaries. The Irtysh is the most significant tributary. It originates in China and is actually the furthest source of the entire system. The Irtysh measures 4,248 kilometers from its source to its confluence with the Ob. The Ob itself measures 2,538 kilometers from its source to that same meeting point. Other important tributaries include the Tom, Chulym, Ket, Tym, and Vakh rivers from the east. From the west and south, the Vasyugan, Irtysh, and Severnaya Sosva rivers flow into the Ob.

The environment surrounding the river changes significantly across its length. The river basin covers a massive area of approximately 2.9 million square kilometers. This basin includes parts of Russia, northern Kazakhstan, western China, and a small part of Mongolia. The topography includes steppe, taiga, swamps, tundra, and semi-desert. In the southern upper Ob valley, the climate is warm enough for grapes, melons, and watermelons. However, the lower reaches consist of Arctic tundra.

Yenisei Ob Kara Sea
Yenisei Ob Kara Sea

The river is also icebound for much of the year. At southern Barnaul, ice stays from early November until late April. At northern Salekhard, the ice lasts from late October until early June.

Human history is closely tied to the Ob. As early as the 11th century, Novgorodians were aware of the lands in western Siberia. They established two trade routes to reach the river. One route traveled through the rivers Sukhona, Vychegda, and Usa. The other route used the Northern Dvina and the White and Kara Seas. By the late 16th century, settlements like Beryozov and Obdorsk were founded. In 1845, steamboats began navigating the middle reaches of the river. By 1916, the Ob hosted 49 steamers.

Barnaul River Port
Barnaul River Port

The completion of the Trans-Siberian Railway later provided more direct transport.

Today, the Ob is essential for many human activities. It provides drinking water, irrigation, and hydroelectric energy. The river hosts more than 50 species of fish. Several hydroelectric power plants exist along the river, with the largest being the Novosibirskaya GES. The city of Novosibirsk is the largest city in Siberia and the third-largest in Russia. It sits on the banks of the Ob. The Trans-Siberian Railway crosses the river at this location. The river system also supports navigation, with a total navigable length of 5,300 kilometers.

However, the river faces modern environmental challenges. The Ob catchment is part of the West Siberian petroleum basin. This area contains large oilfields and significant oil and gas infrastructure. These industries are a major source of pollutants. In the lower reaches, concentrations of petroleum products can exceed limits by 9 to 10 times. The oxygen content in the water has been measured at four times lower than normal. Studies have identified pollutants such as phenols, hydrocarbons, iron, manganese, copper, and phosphate in the water.

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🖼️ Images & Media (4)
File:Operational Navigation Chart C-4, 4th edition.jpg
Operational Navigation Chart C-4, 4th edition.jpg
File:Yenisei Ob Kara Sea.jpg
Yenisei Ob Kara Sea.jpg
File:Barnaul River Port.jpg
Barnaul River Port.jpg
File:Ob river.jpg
Ob river.jpg
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