Zambezi

Zambezi or Zambesi, river, southern Africa, fourth longest of the continent, about 3,540 km (2,200 mi) long and draining an area of some 1,300,000 sq km (502,000 sq mi). It rises in north-western Zambia and flows in a double S curve south-east to the Indian Ocean. From its headwaters, about 1,524 m (5,000 ft) above sea level, it flows through eastern Angola, traverses western Zambia, and forms the border of north-eastern Botswana; it forms the boundary between Zambia and Zimbabwe, and flowing through Lake Kariba, created by the hydroelectric Kariba Dam, it crosses central Mozambique (where it forms a lake behind the Cabora Bassa Dam), then flows into the Mozambique Channel, and empties into the Indian Ocean through many mouths.

In its upper course, totalling about 800 km (500 mi), the Zambezi falls only about 180 m (600 ft). About 100 km (60 mi) below its confluence with the Kwando (Cuando) River, it forms the great cataract known as Victoria Falls (Mosi-Oa-Tunya), and for the next 72 km (45 mi) it rushes through a narrow gorge 122 m (400 ft) deep. It then enters its middle course and flows through hilly country for about 1,300 km (800 mi) to Quebrabasa Rapids, the last great natural barrier to navigation, in Mozambique. In its lower course, it flows through a broad valley to the sea. Besides the Cuando River, the chief tributaries of the upper river are the Kabompo and the Lungwebungu. The Zambezi receives no important tributaries in its middle course; the chief tributary of the lower river is the Shire. The average discharge at the river's mouth is 7 million litres (1.5 million gallons) per second.

Despite such barriers as cataracts, rapids, and sandbars, the Zambezi is navigable for long distances. The navigable reaches of the river and its tributaries total about 645 km (400 mi). The Scottish missionary David Livingstone was the first European to explore the Zambezi. The river is part of the Mana Pools National Park and the Sapi and Chewore Safari Area in Zimbabwe—a UNESCO World Heritage Site designated in 1984.