Rivers Draining to the Arctic Ocean vs. Caspian Sea

Two massive endorheic/exorheic systems in Eurasia:

Arctic Ocean Drainage (Major Rivers)

• Ob (3,650 km) — W. Siberia
• Yenisey (3,487 km) — C. Siberia
• Lena (4,294 km) — E. Siberia
• Mackenzie (4,241 km) — NW Canada
• Yukon (3,190 km) — Alaska/Yukon
• Nelson (2,575 km) — Hudson Bay (Canada)
• Pechora (1,809 km) — NE Europe/Russia
• Northern Dvina (1,774 km) — N. Europe/Russia
• Kolyma, Indigirka, Olenyok — smaller but significant Siberian rivers.

Caspian Sea Drainage (Endorheic Basin)

• Volga (3,531 km) — **80% of inflow**; Russia.
• Ural (2,428 km) — Russia/Kazakhstan border.
• Terek (623 km) — N. Caucasus.
• Sulak (169 km) — Dagestan.
• Kura (1,515 km) — Turkey/Georgia/Azerbaijan.
• Aras (Araks) (1,072 km) — Turkey/Armenia/Iran/Azerbaijan.
• Emba (712 km) — W. Kazakhstan.
• Atrek (563 km) — Iran/Turkmenistan.
• Sefid-Rud (670 km) — Iran (Alborz).
• Qezel Owzan (670 km) — Iran (Zagros).

Key Contrast

The Volga alone drains 20% of European Russia; its management determines the Caspian's fate.