a river that flows through Khabarovsk Krai and then along the border between Khabarovsk Krai and the Yakut ASSR; a right tributary of the Maia River of the Aldan River basin. The Iudoma is 765 km long and drains an area of 43,700 sq km. The river is formed by the confluence of the Nitkan and Avmia rivers, which rise on the slopes of the Suntar-Khaiata Range; it flows south along the Iudoma Range and forms large loops in its lower course. The river is full of rapids.
Fed largely by rain and snow, the Iudoma is also fed by glaciers in its upper course. High water occurs between mid-May and September, with the water level reaching its maximum in July. The mean flow rate is 342 cu m per sec. The river freezes over in October, and the ice breaks up in May. The chief tributaries of the Iudoma are the Akachan on the right and the Gorbi on the left. The lower 271 km of the Iudoma are navigable.