Environment

The Zambezi River

At almost 1,600 miles in length, the Africa River Zambezi is one of the longest rivers in the world, and home to the magnificent Victoria Falls.

5. Description

The fourth longest river system in Africa, the Zambezi arises from its source near a marshy bog on the Central African Plateau of Zambia at an altitude of 4,800 feet above sea level. From there, it flows for 3,540 kilometers eastward into Mozambique before finally draining into the Indian Ocean. As the river flows, it also crosses or borders the African nations of Angola, Namibia, Botswana, and Zimbabwe. The Victoria Falls, a famous and spectacular waterfall on the Zambezi River at the border between Zimbabwe and Zambia, is one of the most notable features of this river. The river and its tributaries drain an area of nearly 1,390,000 square kilometers.

4. Historical Role

The Zambezi river water route was used as early as the 10th Century by Arab traders. The first Europeans to arrive at the Zambezi were the Portuguese, who utilized the river's routes to trade in slaves, gold, and ivory starting in the 16th Century. Prior to the exploration and mapping of the Zambezi River by the Scottish missionary and explorer David Livingstone, the river was believed to arise from an inland sea. In the 1850s, when Livingstone traveled along the river from Sesheke near the Victoria Falls to the Indian Ocean, he was able to draw a detailed map of its course that remained to be the most valid available until the 20th century, when a fully accurate map of the river from its source to its mouth was produced.

3. Modern Significance

The Zambezi River basin is inhabited by around 32 million people. Agriculture is extensively practiced in the fertile floodplains in the upper course of the river. Both commercial and sports fisheries operate on the waters of the Zambezi as well, and many tourists are allured to fish for the many exotic species in this river. The Zambezi River Valley also has rich mineral and fossil fuel reserves, and coal is mined at many places therein. Two of Africa’s largest hydroelectric projects, the Kariba and Cahora Bassa Dams, are also located on the Zambezi River. The arresting natural beauty of the Victoria Falls draws 1.5 million visitors to the area every year. Though the river cannot be extensively used for navigation due to the presence of a number of rapids, some amount of water traffic exists along the short, uninterrupted stretches of the river.

2. Habitat and Biodiversity

A tropical climate prevails in the Zambezi River Basin, as the river flows within the tropics. The upper and middle courses of the Zambezi River experience a milder climate (temperatures between 18° and 30° Celsius) than the lower course of the river. Heavy rain falls between November and April, and these are greater in the lower course of the river as compared to the upper and middle courses. As a result, savanna vegetation dominates the upper and middle river portions of the river basin, while evergreen forests and mangrove swamps cover the lower course of the river’s basin. The Zambezi River Basin supports a great diversity of terrestrial animal species, ranging from powerful mammalian predators like lions, cheetahs and leopards, to game species like waterbuck, impala, eland, and bushbuck, to other mammals like elephants, baboons, and monkeys. Crocodiles and hippopotamuses thrive in the waters of the Zambezi, and so does a great variety of fish species, inclusive of Tiger fish, Yellow fish, bream, and pike. Herons, African open-bills, Wattled cranes, egrets, African fish eagles, and other avifauna are also abundant in the region. Reptiles like African rock pythons, Floodplain water snakes, and Nile monitor lizards also dwell in the Zambezi River Basin.

1. Environmental Threats and Territorial Disputes

The construction of massive dams on the Zambezi River has significantly impacted the ecology of its river basin. The divergence from environmental recommendations during the construction of the Cahora Bassa Dam in 1973 led to widespread ecological damage to the Zambezi’s ecosystems, including a 40% reduction in its mangrove forest coverage. Soil erosion at the lower course of the river, near its mouth, increased considerably, and the seasonal migration of fish species along the river was also severely affected. Since sewage from cities along the river's banks are commonly released into the river without receiving sufficient treatment, the waters of the Zambezi tend to be highly polluted with contaminants. This is leading to eutrophication of the river, as well as loading the river's waters with disease-causing microbes. Cholera, typhus, and dysentery cases have become common due to drinking of the Zambezi's polluted river waters.

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