a river in the northeastern European part of the USSR, the right-hand tributary of the Usa (in the Pechora River basin). The Adz’va is 334 km long, and its basin has an area of 10,600 sq km. It flows across the Bol’shaia Zemlia tundra along the Chernyshev ridge; in its lower reaches the river bed widens and becomes marshy. The Adz’va is fed by snow, which causes a torrential rise in the water level in the spring. Average discharge is 110 cu m/ sec. The water level drops sharply in summer. The river freezes over in October or November and opens up again in May, more rarely in the beginning of June.