What Are The Primary Inflows And Outflows Of Lake Malawi?

Lake Malwai is the southernmost lake in the East African Rift system.

Lake Malawi is one of the African Great Lakes, located between Tanzania, Malawi, and Mozambique. Referred to as Lake Nyasa in Tanzania and as Lake Niassa in Mozambique, it is the southernmost lake in the East African Rift system. Lake Malawi is the fourth largest freshwater lake in the world by volume and the ninth largest by surface area. Additionally, it is Africa’s second deepest lake and third largest in terms of area. Lake Malawi is classified as a meromictic lake, since its water layers do not mix, and has the highest number of fish species of any lake in the world. Although more than 200 rivers flow into Lake Malwai, the Shire River is the lake's only primary outflow.

Geography of Lake Malawi

Lake Malawi is approximately 350-360 miles long and about 47 miles across at its widest point. It has a total surface area of 11,400 square miles, making it the third largest lake in Africa. The lake has an average depth of 958 feet and is 2,316 feet at its deepest point, which is located at a depression in the north-central part, while the shallowest part (660 feet) is located at the far south part of the lake. The lake’s shorelines are located in eastern Malawi, western Mozambique, and southern Tanzania. Lake Malawi is fed by the Ruhuhu River, while the lake flows into the Zambezi River via the Shire River at the lake’s southern end. About 80% of the lake’s water is lost through evaporation, which is significantly higher than the outflow through the Shire River. Lake Malawi lies in a valley where the African tectonic plate that is being split into two, known as divergent plate tectonic boundary. The water levels vary, from 2,000 feet below the current level to over 60 feet above. The lake is also part of Lake Malawi National Park.

Primary Inflow

More than 200 rivers flow into Lake Malawi. However, most of these rivers are short and seasonal, and flow primarily during the rainy season. Some of the significant rivers that feed the lake from the western coast include the Rukuru, Lufira, Dwangwa, Songwe, Linchipe, and Bua, while the Rio Linho and Ruhuhu are inflows from the eastern coast. The primary inflow of Lake Malawi is the Ruhuhu Rover, which is located in southern Tanzania and originates in the Kapengere Range, south of Njombe, and then flows for approximately 100 miles southwest and southeast before entering Lake Malawi just south of Manda.

Primary Outflow

Lake Malawi drains into the Zambezi River via the Shire River. The Shire River, which also links Lake Malawi to Lake Malombe, is characterized by seasonal and long-term variability in flow. Additionally, it is the largest river in Malawi and the only outflow of Lake Malawi. The river is approximately 250 miles long from its source to its mouth. From Lake Malawi, the Shire flows for approximately 12 miles before entering the shallow Lake Malombe, and then flows south through Liwonde National Park, and through the towns of Chikwakwa and Matope. Next, the river turns southeast into the Mozambique plain. The Shire River is joined by a perennial tributary, known as the Ruo River, at the town of Chiromo. The muddy water then passes through the Elephant Marsh before reaching its confluence with the Zambezi River.


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