Author(s)

Romaric Ntchantcho¹, Linus Nche Anye^2,3, Festus Tongwa Aka^4*, Boniface Kankeu⁴, Gaston Wung Buh⁵, Peter Teke Ndifon^6,7, Joseph Metuk Nnange⁴, Joseph Victor Hell⁴

¹Hydrology Research Centre, Institute for Geological and Mining Research (IRGM), Ministry of Scientific Research and Innovation (MINRESI), Yaoundé, Cameroon.
²Branch for Geophysical and Volcanological Research Ekona (ARGV), Institute for Geological and Mining Research (IRGM), Ministry of Scientific Research and Innovation (MINRESI), Yaoundé, Cameroon.
³Department of Earth Sciences, College of Science, Ibaraki University, Mito, Japan.
⁴Institute for Geological and Mining Research (IRGM), Ministry of Scientific Research and Innovation (MINRESI), Yaoundé, Cameroon.
⁵Geotechnology, Environmental Assessment and Disaster Risk Reduction (GEADIRR), Limbe Southwest Region, Cameroon.
⁶Ministry of Scientific Research and Innovation (MINRESI), Yaoundé, Cameroon.
⁷Inorganic Chemistry Department, University of Yaoundé I, Yaoundé, Cameroon.

Compared to large-scale infrequent disasters like volcanic eruptions, earthquakes, and gas explosions from volcanic (maar) lakes, most small-scale everyday disasters (e.g., landslides and floods) are not well reported and documented in Cameroon, despite the fact that cumulatively, they cause the most casualties and distress to the people affected. This paper documents a debris flow that occurred on the 1^st of August 2012 in Kakpenyi, a quarter found in Tinta, one of the villages of Akwaya Sub Division in Manyu Division of the Southwest Region of Cameroon. The event started from the western slope (06°14.350'N & 09°31.475'E) of a hogback in the settlement, and mobilized ca 3.47 × 10⁶ m³ of material over a ca 1 km distance. The material was made up of a chaotic mix of mud, rock fragments, boulders, twigs, tree logs, trunks, and roots. Its distal part dammed river Kakpenyi forming a 10 m deep lake which eventually safely emptied itself. No casualties were recorded but 20 people got injured and 21 people lost farmland. The debris flow was not caused by earthquake shaking. Instead, inappropriate land use acted as a remote cause to predispose the steep slope, while heavy rainfall triggered the flow. Verbal reports talk of a similar event 40 years ago in the area. This shows that Kakpenyi is vulnerable to this kind of hazard, requiring that major infrastructural development projects like roads and bridges in the area be preceded by detailed hazard and vulnerability assessments.

Debris Flow, Kakpenyi-Tinta, Land Use, Rainfall, Debris-Flow-Hazard Evaluation

Ntchantcho, R. , Anye, L. , Aka, F. , Kankeu, B. , Buh, G. , Ndifon, P. , Nnange, J. and Hell, J. (2017) The Debris Flow of 1^st August 2012 in Kakpenyi-Tinta (Akwaya Sub Division) Southwest Cameroon—I: Event Description, Causes and Impacts. Open Journal of Geology, 7, 1337-1351. doi: 10.4236/ojg.2017.79089.