ASSESSMENT OF SOIL EROSION AND SEDIMENTS ACCUMULATION IN KAMBENJE VILLAGE, MULANJE

This dissertation investigates the critical environmental issues of soil erosion and sediment accumulation in Kambenje village, Mulanje district, Malawi, particularly in the aftermath of Cyclone Freddy in March 2023. The cyclone's extensive flooding increased pre-existing conditions of deforestation, unsustainable farming, and climate change, threatening agricultural productivity, water quality, and environmental sustainability. The study area, located in the southern part of Malawi, is characterized by steep slopes and is ecologically significant due to its proximity to the Mulanje Mountain Forest Reserve.The research employs a mixed-methods approach, combining qualitative and quantitative techniques. Field observations, GIS, remote sensing, and geotechnical lab analysis were used to assess the extent of soil erosion. Data collection involved generating a geological map using Arc GIS software, acquiring land use/land cover data from Sentinel-2, deriving slope data from a Digital Elevation Model (DEM), and obtaining annual rainfall data from the CHRS data portal ( https://livingatlas.arcgis.com/landcoverexplorer/ ). Soil samples were collected and analyzed for particle size distribution, shear strength, porosity, and permeability to determine their contribution to soil erosion and sediment accumulation. The study's findings reveal that the soils in Kambenje Village vary in their susceptibility to erosion. Soils with a high proportion of fine particles and low shear strength are more prone to erosion while those with higher porosity and permeability exhibit greater resilience. The slope analysis indicates that steeper areas are at higher risk due to increased runoff velocity. Overall, the combination of factors such as land use practices, topography, and rainfall patterns significantly influence the rate of soil erosion and sediment accumulation in the area. The study concludes that addressing soil erosion and sediment accumulation in Kambenje Village is significant for maintaining agricultural productivity, water quality, and infrastructure integrity. It emphasizes the need for sustainable land management practices to mitigate soil loss and its associated environmental and socioeconomic impacts. Recommendations include a further study of soil erosion and sedimentation to prevent further degradation.