TITLE:
Study of Multi-Origin Hazards and Assessment of Associated Risks in the Lefo Caldera (Bamenda Volcano, Cameroon Line)
AUTHORS:
Zangmo Tefogoum Ghislain, Nkouathio David Guimolaire, Kagou Dongmo Armand, Gountie Dedzo Merlin, Kamgang Pierre
KEYWORDS:
Hazards, Risk, Anthropogenic Activities, Lefo Caldera
JOURNAL NAME:
International Journal of Geosciences,
Vol.5 No.11,
October
27,
2014
ABSTRACT: The Bamenda Volcano (BV) (2621 m) is a stratovolcano situated in the
Cameroon Line (CL). BV includes Mount Lefo (2534 m) which is situated on its
southern slopes and contains one elliptical caldera (3 × 4 km). This caldera is
propitious to farming and breeding activity. Despite these profitable assets,
Lefo caldera (LC) is an amphitheater of the occurrence of multi-origin hazards
that have direct or indirect impacts on the biodiversity and human patrimony. The
most present hazards are those of meteorological origin. Numerous combined
factors (steepest slopes, heavy rainfalls, weathered state of volcanic products…)
rule these hazards. These factors gave rise to the occurrence of landslides, gullies
erosion and rock falls which occur precisely on caldera northern and eastern
rims. Hazards of anthropogenic origin are based on the destruction of the
vegetation cover by the population for dealing, firewood and building issues.
Moreover, during the breeding activity, the cattle covers the caldera
throughout the day; this unevens the topography and destroys the meadow. Hazards
of volcanological origin are not yet occurring in LC; but the recent Lake
Monoun (1984) and Nyos (1986) CO2 eruptions, mount Cameroon
eruptions (1999 and 2000) and mount Oku Lake event (2011) which are close to
the BV and, the age of 0 Myr of basalt, constitutes a subject of controversy
toward the reactivation of the Cameroonian hotspot faults. The assessment of risks in LC was
based on the average income of breeding activity and house investment. The economy of LC is
valued at about US$527472.527. The level of such risk will be important in case
of loss of human beings and the destruction of geomorphosites’ values.
In order to reduce the level of looses in this zone, hazard and risks maps are
provided in this paper as well as some recommendations.