The (''Енисе́й'') is the greatest
River system flowing to the
Arctic Ocean , slightly shorter but with 1.5 times the flow of the
Mississippi -
Missouri . Rising in
Mongolia , it follows a northerly course to the
Kara Sea , draining a large part of central
Siberia , the longest stream following the Yenisei-Angara-Selenga being about 5500 km.
The upper reaches, subject to rapids and flooding, pass through sparsely populated areas. The middle section is controlled by a series of massive hydroelectric dams fuelling significant Russian primary industry. Partly built by
Gulag labor in Soviet times, industrial contamination remains a serious problem in an area hard to police. Moving on through sparsely-populated
Taiga , the Yenisei swells with numerous tributaries and finally reaches the Kara Sea in desolate
Tundra where it is icebound for more than half the year. As with other Siberian rivers, the flow has increased recently, believed to be related to
Global Warming . A concern is that altered salinity in the Arctic may have a global impact on ocean currents.
The Yenisei rises in two major headstreams: the Bolshoi (greater) Yenisei also known as the Bii-Khem (Бии-Хем) rises in the
Tuva region on the S flank of the Eastern
Sayan Mountains and north of the
Tannu-Ola Mountains at ; the Malyy (lesser) Yenisei also known as the Kaa-Khem (Каа-Хем) rises in the Darhat (
Rift ) valley in
Mongolia . Recent research has shown that the narrow exit to the Darhat Valley has regularly been blocked by ice producing a lake as large as neighbouring
Lake Khuvsgul . When the glaciers retreated (the last time 9300 years BP) as much as 500 km³ of water would have escaped, possibly catastrophically.
These two headstreams flow west converging at
Kyzyl , and on meeting the east-flowing Khemchik River head north through a canyon in the Western Sayan mountains. The Yenisei emerges from the mountains onto an area of steppe where its first control is the 30m dam at Mayna. This section is around 700 km.
The 320 km (partly navigable) Upper Angara feeds into the northern end of
Lake Baikal from the
Buryat Republic but the largest inflow is from the
Selenga which forms a delta on the south-eastern side. The longest tributaries rise on the eastern slopes of central Mongolia's Hangayn Nuruu mountains. Another tributary, the passes through the Mongolian capital,
Ulaanbaatar while the '''Egiin''' drains
Lake Khuvsgul .
