The Kilombero Valley is a 220 km long and up to 70 km broad floodplain in southern Tanzania’s Rufiji River watershed, situated between the Udzungwa Mountains and the Mahenge Hills. The Kilombero River is formed by the confluence of many streams throughout the valley. Water flow from the steep tributaries quickly reaches the valley floor during the wet season, transforming it into a vast swamp. The large valley served as a dry-season refuge and provided several connecting pathways for animal populations migrating between the Udzungwa range and the Selous Game Reserve, playing a crucial role in regional connectivity in southern Tanzania.
The floodplain used to be home to vast animal populations, including elephants and a large number of critically endangered puku antelope. Beginning in the 1990s, the environment witnessed significant transformation as a result of ongoing human immigration and expanding settlements, huge expansion of rice production and cattle grazing, deforestation, and infrastructural development.
The valley is formed by the Kilombero River, which flows through the region and eventually empties into the Rufiji River. The Kilombero Valley is known for its rich biodiversity, including its diverse plant and animal species, as well as its importance as an agricultural and economic hub.
Geography
The Kilombero Valley is located in the southern part of Tanzania and covers an area of over 63,000 square kilometers. The valley is mainly composed of alluvial soil, deposited by the Kilombero River during periods of flooding. The Kilombero River flows through the valley for approximately 500 kilometers, from its source in the Mahenge Mountains to its confluence with the Rufiji River.
Biodiversity
The Kilombero Valley is home to a diverse range of flora and fauna, including several endemic and endangered species. The valley is particularly known for its birdlife, with over 300 bird species recorded in the region. The valley is also home to several large mammal species, such as elephants, buffaloes, and hippos. The river is also known for its fish species, with over 50 different species recorded in the region, including catfish, tilapia, and lungfish.
Agriculture and Economy
The Kilombero Valley is an important agricultural region in Tanzania, producing crops such as rice, maize, cassava, and beans. The valley’s fertile soil, combined with the river’s water resources, make it an ideal location for agriculture. The valley is also home to several large sugar plantations, which are a significant source of income and employment for the region.
Threats and Conservation
The Kilombero Valley and its biodiversity face several threats, including deforestation, overgrazing, and pollution from agricultural runoff. Climate change is also affecting the region, with changing rainfall patterns and increasing temperatures affecting both agriculture and wildlife. However, several conservation initiatives are underway to protect the valley and its biodiversity, such as promoting sustainable agriculture and forestry practices, improving water management and conservation, and enhancing the participation of local communities in conservation efforts.