Katsina-Ala drainage basin 
event of the dam failure, 
es within the Earth crust, 
down the Katsina-Ala and 
' distinctly marked fracture 
rection and may serve as 
r transport. Fourteen Local 
Nigeria and Cameroun are 
ollapse of the lake because 
nd contiguity and tangency 
he floodplains (Figure 2). 
Many studies have shown that the fault lines are still very active. 
(Mesmin et al, 2000) and this risk is highly linked to the 
increasing number of people in this region. The return of the 
local population, who for the past 20 years had been living in 
Bua Bua and other resettled localities, has increased the fear of a 
more deadly disaster (Tazief, 1989, Mesmin et al 2010). Some of 
the consequences include the depletion of underground water, 
deforestation and extreme poverty and death, particularly in the 
event of another gas explosion and flooding. The degasification 
process which is still in progress points to this fact. The gas 
emitted during the 1986 explosion mostly flowed across the fault 
lines; the population which settled along these lines were the 
most affected. The tectonic activities and the frequency of 
landslides, especially during the rainy season, constitutes another 
risk to the population To this effect, the region needs to be 
constantly surveyed and monitored.(Mesmin et al 2000). 
Research findings from fieldwork revealed that the survivors of 
the previous disasters are the poor people who are socially 
vulnerable to the impacts of the past gas explosion tragedy. 
Twenty two years after the Lake Nyos Disaster, the survivors 
have not regained their livelihoods; many of them still have very 
low resilience and limited coping strategies. This include failed 
government promises to provide financial and material assistance 
to disaster victims, provide basic social facilities and ameliorate 
their housing and living conditions and also the inability to solve 
other social problems within resettlement zone despite persistent 
complains (Bang, 2008). While huge sums of money are pumped 
into the degassing project, the disaster survivors languish in 
abject poverty in the resettlement camps with a catalogue of 
numerous social problems that remain unresolved. This 
unfortunate situation made many of them to go back to their 
former means of livelihood and settlements such as the sale of 
cattle, farming and hunting, thus increasing their vulnerability to 
the Lake Nyos-triggered disaster. 
The results from field work and hydrological modelling in a GIS 
provide viable and reliable information on the dam’s fragility 
and the vulnerability of the region to floods and erosion. 
5.0 CONCLUSIONS 
The frequency of occurrence of natural and man-induced hazards 
and disasters in West Africa sub-region and globally has 
necessitated the need for constant studies using multi- 
disciplinary approaches to provide adequate information that will 
help mitigate the impacts of these hazards and disasters. Poor 
disaster management policies and practices are partly responsible 
for the poverty and poor living conditions of the survivors, and 
this appears to be a key determinant for the social vulnerability 
of the local population to the effects of the past disaster and 
subsequent hazards. The management of the disaster associated 
with lake Nyos gas explosion in 1986 shows a typical example of 
unfulfilled government’s promises to disaster survivors and a 
failed policy towards disaster risk reduction. The foregoing 
therefore informed the need for disaster mitigation planners to 
alert the governments and other relevant NGOs of their 
responsibilities to the disaster community ahead of any disaster 
occurrence (Liebow and Wolfe, 1993). 
Lake Nyos holds an enormous volume of CO2 which erupted 
and kill over 3000 people and livestock at Oku volcanic field in 
1986. Integration of satellite data and hydrological models in a 
GIS combined with social and economic development surveys of 
the settlement/population around the lake and Katsina-Ala 
11 
drainage basin will go a long way in improving the management 
of future disaster in the region. Early review of available flood 
hazard information and the integration of complementary flood 
hazard assessments data will allow planners to foresee and 
evaluate potential problems related to river hydraulics and 
floodplain dynamics. The nature of social vulnerability and risk 
perception of community to hazards is also essential and must be 
incorporated into disaster risk management policy and practice 
by the authorities. Then, mitigation measures can be identified to 
avoid or minimize these hazards; this can be incorporated into 
the formulation of specific sectoral investment projects. 
5.1 References 
Baxter, P. J.; Kapila, M.; and Mfonfu, D. (1989): Lake Nyos 
disaster, Cameroon, 1986: the medical effects of large scale 
emission of carbon dioxide? British Medical Journal, v 298 
pp.1437-41 
Bang H.N, (2008) Social vulnerability and risk perception to 
natural hazards in Cameroon two decades after the lake Nyos gas 
disaster: what future prospect for the displaced disaster victims? 
Paper presented at the 2008 summer academy for social 
vulnerability at the united nations university-institute for 
environment and human security (unu-ehs) in Germany. 
Blaikie, P.; Cannon, T.; Davis, L; Wisner, B. (1994): At Risk: 
Natural hazards, peoples vulnerability, and disasters. London: 
Routledge. 
Freeth, J. and Kay R., (1987): The Lake Nyos gas disaster. 
Nature, vol 7000, no 325 pp.104 105 
Kling, G.; Clark, M.; Compton, R.; Devine, D.; Evans, W.; 
Humphrey, A.; Tuttle. M. (1987): The 1986 Lake Nyos gas 
disaster, Cameroon, West Africa. Science, vol 236 pp. 169-175 
Krimsky, S.; Golding, D. (Eds) (1992): Social theories of risk. 
Praeger Publications, CT 
Kusakabe, M.; Ohsumi T.; Aramaki S. (1989): The Lake Nyos 
gas disaster: Chemical and isotopic evidence in waters and 
dissolved gases from three Cameroonian crater lakes, Nyos, 
Monoum and Wum. Journal of Volc. and Geoth. Res, vol 39 pp. 
167-185 
Liebow, E.; Wolfe A. (1993) Communities at risk: 
communication and choice of environmental hazards. Environ. 
Prof, vol 15 pp 237-239 
Shanklin, E. (1988): Beautiful Deadly Lake Nyos: The Explosion 
and its Aftermath. Anthropology Today, vol 4 no 1 pp. 2-14 
Smith, K. (2001): Environmental Hazards: Assessing risk and 
reducing disasters. Third Edition Routledge, London. 
Tazieff, H. (1989): Mechanisms of the Nyos carbon dioxide 
disaster and of so-called phreatic steam eruptions. Journal of 
Volcanology and Geothermal Research, vol 39 pp.109-116