By Hugo Odiogor
The prospects of 70,000 Nigerians living on the border line of Lake Nyos being swept off by a bursting dam in Cameroon remains a living nightmare even as the Federal Goverment puts a brave face on new source of diplomatic tension between Nigeria and the central African country.
The recent upsurge in flooding round the world has drummed home the massive environmental threat of climate change, but more importantly, it thrown up the challenge of how countries can cope with the fall out of climate change.
The National Emergency Management Agency (NEMA) is assuring Nigerians that it has the capacity to cope with disasters thrown up by nature, but the experience of the recent flood that swept through Sokoto, Jigawa, Lagos, Ogun states, among others, belie the optimistic posturing of NEMA.
Lake Nyos is situated on the Cameroon Mountain is at an elevation higher than the adjoining Benue and Katsina-Ala plains in Nigeria. The lake flows into the tributaries from which the Katsina–Ala River takes its source, crossing the Nigeria-Cameroon border at a point 108 kilometers from Nyos.
The river then proceeds north-westerly into Benue River at a point 40 kilometers east of Makurdi, Benue State.
The major threat to Nigeria is in the highly unstable upper parts of the lake body which holds about 50 million cubic meters of water. An analysis of Lake Nyos dam-break reported by WADASCO (1990) shows that “the flood produced will reach about 19000m2/s at the dam site corresponding to a flow depth of over 18 meters.
Due to the attenuation of the wave, the flood peak will be reduced to 400 m3/s and flow depth of 14.5meters at the Nigeria-Cameroon border, 250 m3/s and 8.8meters at Kashimbilla and 2000 m3/s and 4.5 meters at Katsina-Ala town.
“As the flood enters Nigeria, it spreads over wide flood plains inundating many towns, villages, hamlets and farm lands. Between Cameroon border and River Benue, it is estimated that over 50 settlements including Katsina-Ala, Kashimbilla, Waya, Manga, Gamovo and over 15,000 hectares of land will be flooded.
Over 35,000 people and 20,000 herds of cattle and other livestock will be caught within the flood part and could perish.”
According to the Director General National Emergency Management Agency (NEMA), Alhaji Mohammed Sani Sidi, the Agency has conducted some studies and developed various measures to counter the adverse fall out of the activities of the lake. These are classified under Absorption, Mitigation, and Elimination depending on the location.
According to him the absorption measures involve the preparation of the endangered areas to absorb the initial effects of the possible flooding of the Lake.
They include; prediction of the Lake Nyos Dam-break and flood arrival time; flood inundation mapping; emergency preparedness planning; containment of flood by a buffer dam; mitigation measures among others.
It must be observed that Nigeria’s attempt to manage likely adverse effect of the Lake Nyos has been low on its diplomatic front as can be seen in the inter-ministerial committee called Technical Committee on Earthquake Phenomena (NTCEP) coordinated by the Federal Ministry of Science and Technology.