Integrated assessment of landslide effects triggered by the 2020-2021 rainfall in Uvira Territory, on the northwestern shore of Lake Tanganyika

The city of Uvira faces increasing risks of landslides and flooding, driven by both human activities (deforestation, unsuitable and intensive agriculture practices) and natural factors (steep slopes, heavy rainfall). A combined analysis of field data and Google Earth satellite imagery identified 221 events related to landslides and erosion, including 125 landslides (56.56%), 82 cases of gully erosion (37.10%), and 14 instances of bank erosion (6.33%). Intense rainfall such as the 114 mm recorded over 9 hours in April 2020 has intensified these hazards, leading to sudden floods. Between 2020 and 2021, human activities like construction in vulnerable areas and slope deforestation further amplified the risks. At least 2,707 riverside dwellings are exposed to sediment deposits. Three severely degraded zones have been identified as priorities for reforestation: (1) from Kaala stream to the right slopes of the Mulongwe River, (2) from Kakungwe stream to Ruzozi stream, and (3) the area surrounding Kalundu port. Recommended interventions include mountain stabilization, reforestation of degraded areas, and relocation of buildings away from high-risk zones.