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The Wilderness Project EXPEDITION REPORT ZAMBEZI RIVER: BAROTSE FLOODPLAIN ZAMBIA 2023
| Author: | Lauren Searle – The Wilderness Project |
| Language: | |
| Topic: | Water and River Basins |
| Type: | Research |
| Last updated: | 14 April 2026 |
In 2023, The Wilderness Project launched a series of research expeditions in Southern Africa. One of the goals of these expeditions was to survey the Zambezi River, from its several sources to its outflow into the Mozambican Indian Ocean. As part of this effort, a research transect was conducted on the Zambezi River in Zambia — starting at the town of Chavuma at the Angolan border and ending downstream of the Barotse Floodplain at Sioma. The total distance of the transect was 560 km, all of which was travelled in purpose-built canoes. This report summarises the findings of the expedition and presents an assessment of the health, human development, and ecology of the Zambezi River between Chavuma and Sioma.
People and Fisheries
A total of 3,558 people were counted along the transect, a density of 6.35 people/km which is substantially higher than the upstream reaches in Angola (2.3 people/km). More than half of the people were encountered within the Barotse Floodplain in association with ubiquitous seasonal fishing camps (N = 242). Fishing was the most common human activity, with a total of 178 individuals observed along the transect—averaging one fisher every 3 km. Most fishing on the Barotse Floodplain occurs at night, which likely creates an underestimation of activity since the survey was conducted during the day. Overfishing and destructive practices, such as the use of Sefa-sefa nets, have greatly reduced fish stocks, forcing fishers to target smaller species and juveniles. Given the strong reliance on fish as a primary livelihood, and the limited availability of alternative income sources, both fish populations and fisher incomes are
likely to decline.
Agriculture and Water Quality Risks
Agriculture poses an increasing threat to the Barotse Floodplain as farmers seek more reliable water amid Zambia’s worsening drought. This shift is evident in the intensifying agricultural land use along the floodplain margins. The Kabompo River, contaminated by mining, threatens the water quality of the Zambezi River and Barotse Floodplain. While parameters along the transect remained within acceptable levels, water quality declined sharply at the Kabompo confluence. These findings highlight the need for ongoing monitoring to assess the impact of upstream mining on this vital ecosystem.
Biodiversity
The Barotse Floodplain is one of Zambia’s most critical wetland ecosystems, hosting the highest recorded density of wetland birds in the country. Observations along the transect documented a density of 115.24 birds/km, far surpassing other wetland ecosystems like the Bangweulu Wetlands (4.91 birds/km) and the
Lukanga Swamps (11.27 birds/km). Despite this ecological significance, the Barotse Floodplain faces mounting threats from overfishing, agricultural expansion, and climate change.
Hydrology and Wetland Function
The Lungwebungu and Kabompo rivers contribute an estimated 43% of the Zambezi River’s flow after the floodplain, with additional water originating from the surrounding pan-belt. As the dry season progresses, the pan-belt’s storage effect becomes more pronounced, gradually releasing water and sustaining
downstream flows. Functioning as a natural reservoir, the Barotse Floodplain mitigates hydrological extremes, ensuring stable conditions for biodiversity, fisheries, and agriculture. Contrary to the notion that floodplains merely disperse excess water, the Barotse system plays a crucial role in regulating river
flow, highlighting the need for proactive management in the face of upstream modifications and climate variability.
A total of 3,558 people were counted along the transect, a density of 6.35 people/km which is substantially higher than the upstream reaches in Angola (2.3 people/km). More than half of the people were encountered within the Barotse Floodplain in association with ubiquitous seasonal fishing camps (N = 242). Fishing was the most common human activity, with a total of 178 individuals observed along the transect—averaging one fisher every 3 km. Most fishing on the Barotse Floodplain occurs at night, which likely creates an underestimation of activity since the survey was conducted during the day. Overfishing and destructive practices, such as the use of Sefa-sefa nets, have greatly reduced fish stocks, forcing fishers to target smaller species and juveniles. Given the strong reliance on fish as a primary livelihood, and the limited availability of alternative income sources, both fish populations and fisher incomes are
likely to decline.
Agriculture and Water Quality Risks
Agriculture poses an increasing threat to the Barotse Floodplain as farmers seek more reliable water amid Zambia’s worsening drought. This shift is evident in the intensifying agricultural land use along the floodplain margins. The Kabompo River, contaminated by mining, threatens the water quality of the Zambezi River and Barotse Floodplain. While parameters along the transect remained within acceptable levels, water quality declined sharply at the Kabompo confluence. These findings highlight the need for ongoing monitoring to assess the impact of upstream mining on this vital ecosystem.
Biodiversity
The Barotse Floodplain is one of Zambia’s most critical wetland ecosystems, hosting the highest recorded density of wetland birds in the country. Observations along the transect documented a density of 115.24 birds/km, far surpassing other wetland ecosystems like the Bangweulu Wetlands (4.91 birds/km) and the
Lukanga Swamps (11.27 birds/km). Despite this ecological significance, the Barotse Floodplain faces mounting threats from overfishing, agricultural expansion, and climate change.
Hydrology and Wetland Function
The Lungwebungu and Kabompo rivers contribute an estimated 43% of the Zambezi River’s flow after the floodplain, with additional water originating from the surrounding pan-belt. As the dry season progresses, the pan-belt’s storage effect becomes more pronounced, gradually releasing water and sustaining
downstream flows. Functioning as a natural reservoir, the Barotse Floodplain mitigates hydrological extremes, ensuring stable conditions for biodiversity, fisheries, and agriculture. Contrary to the notion that floodplains merely disperse excess water, the Barotse system plays a crucial role in regulating river
flow, highlighting the need for proactive management in the face of upstream modifications and climate variability.
