a river in the USSR and China. It rises in the Eastern Tien-Shan from two sources, the Tekes and the Kunges, which converge in Sinkiang (China). The river empties into Lake Balkhash. Length from the confluence of the Tekes and the Kunges, 1,001 km; from the source of the Tekes, 1,439 km. Basin area, 140,000 sq km.

In its upper reaches the Hi is a mountain river. Below the mouth of the major right-bank tributary, the Kash, the valley broadens, and the Hi divides into branches. Up to the city of Kapchagai, the river flows along the bottom of a broad hollow, with low banks that are swampy in places; lower on it enters the deep Kapchagai gorge, where the Kapchagai Hydroelectric Power Plant has been built. After the entrance of the last tributary, the Kurty River, the valley widens abruptly, and the river flows amid the sands of the Sary-Ishikotrau and the Taukum. The dry riverbed of the Bakanas branches off 340 km from the mouth of the Hi; the ancient delta of the Hi begins here. The present-day delta (area, 9,000 sq km) begins 100 km farther downstream; it has many branches, which are overgrown with reeds. The principal branches are the Zhideli, the Hi (navigable), and the Topar.

The Ili is fed by ice and snow. The average annual water discharge at the village of Uchzharma (270 km from the river’s mouth) is 479 m³/sec; where the river empties into Lake Balkhash, the discharge is 329 m³/sec. The average turbidity is about 1 kg/m³. The river freezes over in December and opens up in March. Its principal tributaries are the Kash and the Khorgos on the right and the Charyn, Chilik, Talgar, Kaskelen, and Kurty on the left. The Hi and its tributaries are very important for irrigation. The Hi has abundant fish, and its delta has muskrat industry. From the city of Kuldzha (Inin, China), the Hi River is suitable for navigation by vessels with a small displacement. Within the borders of the USSR there is regular navigation from the national frontier to the landing of Balkanas, below which trips are made by motor launches.