Any body of water that collects in a depression or low-lying inland area is called a Lake. The size of lakes can vary from a few square metres to a hundreds of square kilometers. Lakes can be formed in different ways and lakes of Zambia are no exception. These ways include: Artificial or man made, earth movement and erosion
People build dams across streams and rivers, resulting in artificial lakes varying in sizes.
This is done to use water resource either for generating electricity or for irrigating farmlands.
Examples are Lake Kariba (shared by Zambia and Zimbabwe) and Cabora Bassa in Mozambique. Both these lakes were created by the building of dams on the Zambezi River.
Earth movements or Rift valley lakes
The earth’s outer layer, also called the lakes crust, has two main movements.
Forces of compression, where the crust is flexible, results in the earth’s crust bending or warping to form Fold Mountains.
Tension forces occur where two parts of the earth’s crust are moving or pulling away from each other, causing deep fractures in the earth’s crust.
Water is then collected in these deep fractures forming lakes.
These lakes are called rift valley lakes.
Erosion or Depression lakes
Lakes could also be formed by erosion caused by the action of wind or water.
Lakes formed in this way are usually not very deep. Lake Bangweulu may have been formed as a result of wind erosion.
River erosion occurs after the stream cuts a new path straight through a bend in the river, called a meander. The lake formed by this type or erosion is called an oxbow lake. Oxbow lakes are often found on the Balozi floodplains during the dry season
Lake Kariba
One of the world’s largest artificial lakes is Lake Kariba, found on the Zambezi River along the Gwembe valley in the southern province of Zambia.
The lake is shared by Zambia and Zimbabwe.
Lake Kariba was created was created by the building of the Kariba dam, mainly for the generation of hydro-electric power by Zambia and Zimbabwe on the south bank of the Zambezi River.
Another power station has since been built on the north bank by Sinoh Hydro Power Company.
Lake Tanganyika
Lake Tanganyika lies in the northern province of Zambia.
The lake forms part of the East African Rift valley. It is believed to be the second largest, and also the second deepest, freshwater lake in the world.
The lake is shared by Zambia, Tanzania, Democratic Republic of Congo and Burundi.
It forms an important waterway that provides transport connections by boat and ferry between these countries.
Lake Mweru
Lake Mweru is a depression lake that lies on the border between Zambia and the Democratic republic of Congo (DRC).
The Luapula River flows into the lake from Zambia. It is the only one of the four largest rivers in Zambia that flows northward from the Congo-Zambezi watershed.
On the DRC side, the Ruvuma River flows from the lake, from where it later joins the Congo River.
Lake Mweru-wantipa
This is a smaller depression lake than the bigger Lake Mweru.
It lies in the Northern Province of Zambia and is not shared with any other country.
The lake is also known for swamps that lie around it.
Lake Bangweulu
You have already learnt that the Chambeshi River flowing into this lake is the same river as the Luapula River that flows from the lake.
The lake mostly lies just above 1000 metres above sea level.
The Luapula River probably got its name because in the local Bemba language ukupula means ”pass through”, like the river passing through Lake Bangweulu.
The lake is almost surrounded by the Bangweulu swamps.