Landslides in the Rumphi District of Northern Malawi: characteristics and mechanisms of generation

• Published in: Natural hazards (Dordrecht) Vol. 54; no. 3; pp. 657 - 677
• Main Authors: Msilimba, G. G., Holmes, P. J.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-09-2010; Springer; Springer Nature B.V
• Subjects: Civil Engineering; Deforestation; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Management; Exact sciences and technology; Geological hazards; Geophysics/Geodesy; Geotechnical Engineering & Applied Earth Sciences; Human influences; Hydrogeology; Landslides; Landslides & mudslides; Liquefaction; Natural Hazards; Natural hazards: prediction, damages, etc; Original Paper; Pore pressure; Rain; Slope stability; Water pressure; Malawi; East Africa; Africa; Landslides; Malawi; Liquefaction; Hazard; basement; regolith; rainfall; fine-grained materials; water pressure; weathering; liquefaction; slopes; human activity; deforestation; sand; pore pressure; landslides; instability; slope angle; soils
• ISSN: 0921-030X; 1573-0840
• DOI: 10.1007/s11069-009-9495-8

Landslides are a common phenomenon in all the regions of Malawi. A number of historical landslides have been documented and are summarized here. This paper examines the occurrence of landslides in the Rumphi District of Northern Malawi. The study is based on a detailed study of 98 landslides that occurred in 2003 at Ntchenachena and Chiweta areas in the Rumphi District. This paper examines factors that contributed to and caused these landslides. The paper suggests that landslides were triggered by 206 mm of rain received in 2 days. The high percentage of medium to fine sand and abrupt rise in pore pressure accelerated the process of liquefaction at Ntchenachena. Cleft water pressure at the point between regolith and soil mass caused a number of slides in the Chiweta areas. High slope angles, deep weathering of the basement and high annual total rainfall contributed to the slope instability. Human activities through cultivation on steep slope, slope remodeling, and deforestation significantly altered the conditions of the slopes, thereby increasing the degree of landslide hazard present in these areas.