What are the main sources of water for the Ob River?

The primary sources of water for the Ob River are the melting of seasonal snow and rainfall. While these two factors account for the majority of the river's water supply, a smaller portion of its discharge is derived from groundwater, mountain snow, and glaciers.1

The river's flow is heavily influenced by seasonal melting patterns. In the upper reaches, spring floods are driven by the melting of snow on the plains, followed by a second phase caused by the melting of snow in the Altai Mountains. The river system also relies on numerous tributaries, such as the Irtysh, which contribute to the overall drainage of the vast Ob basin.12