Chuna

(called the Uda River in the upper course), a river in Irkutsk Oblast and Krasnoiarsk Krai, RSFSR; right headstream of the Taseeva River in the Enisei basin. The Chuna River is 1,203 km long and drains an area of 56,800 sq km. It rises in the Uda Range of the Vostochnyi Saian. The upper course flows through a narrow intermontane valley; the lower course flows through the Central Siberian Plateau. As the river intersects traps, it forms the Tiumenets, Voron, Arakan, and Kosoi rapids. It is fed mainly by rain and snow. The mean flow rate is 300 cu m per sec. The Chuna freezes in late October or November, and the ice breaks up in late April or May. The river is used to float timber, and there is local navigation. The city of Nizhneudinsk is on the Chuna.