Flood hazards are the most common and destructive of all natural disasters. Each year, flood disasters cause tremendous loss of lives and property, thereby causing devastating impact on the socio-economic conditions of the people. In Nigeria, the situation is becoming increasingly worrisome, prompting the need for flood management. GLORIA USMAN writes.
In recent years, risk-based approaches have received increasing attention as means to ‘manage’ flood hazards. Nigeria has suffered from various disasters like flood, drought, communal clashes, riots and terrorist attacks.
At least 25 million people living in coastal regions of the country are at risk of the devastation of floods before the end of the year, according to the National Emergency Management Agency (NEMA) report.
The assessment exercise undertaken by NEMA and its partners, had revealed that flood plains of many of the country’s rivers are susceptible to flooding during the rains. States such as Rivers, Niger, Benue, Cross River, Sokoto, Katsina and Imo are consequently threatened by flooding.
The coastal areas of Lagos, Ondo, Delta, Rivers, Akwa Ibom and Cross River states have already experienced severe flooding impacts since the beginning of the rainy season, due to factors such as absence of surface drains and blockage of existing drains with municipal waste, refuse and eroded soil sediments.
Nigerian towns and cities are generally characterised by poor drains and are, therefore, prone to flooding, particularly cities like Lagos, Ibadan, Aba, Calabar, Maiduguri and Port Harcourt. NEMA had been stepping up its advocacy and campaign efforts in order to protect people living in the endangered areas.?
“The agency is warning people of impending danger to their lives and, where necessary, urging states and local authorities to relocate people in disaster-prone areas,” it warned in one of its reports.?
Flooding has been a persistent problem in the country’s coastal areas with tragedies recorded this year alone resulting in the death of hundreds of people; the Plateau experience of July being the worst in recent months.
During the presentation of 2012 seasonal rainfall prediction and the review of 2011 Nigerian climate, director-general of Nigerian Meteorological Agency (NIMET), Dr. Anthony Anuforom, said the essence of the presentation was to alert state governments, farmers, aviation stakeholders and others that rely on weather and rainfall predictions in planning their activities to take precaution.
Anuforom said seasonal rainfall predictions are produced based on the variability of rain bearing synoptic systems over the country as ENSO phenomenon is categorised into three phases namely: El-Nino (warm phase), La Nina (cold phase) and ENSO-Neutral phase. Each of these phases dominating the climate scenario brings distinct weather (rainfall) pattern over the country.
“In 2012, weak La-Nina which dominated the synoptic situation early in the year (Jan – Feb) is expected to weaken shortly afterwards and dissipate during March – April. La-Nina is predicted to transition to ENSO-Neutral during March – May 2012.
The 2012 predictions are built around these climate scenarios, i.e. starting with weak La-Nina early in the year (with its early and heavy rainfall in some parts of the country), and ENSO-Neutral conditions during the major part of the rainy season.
“In March 2012, Nights are likely to be colder than normal in March, particularly in the northeast corner of the country. In April 2012, temperature pattern will be mainly normal. Remnants of weak La Nina is expected to account for early rains in some places. Early rains often accompanied by destructive storms and winds. In 2012, the cessation period is predicted to be between October and November over the country.
On Agriculture he said “normal growing season’ in 2012 is expected to result in good agricultural yields; farmers are advised to source and undertake early planting of improved high-yielding varieties of seeds, cuttings and seedlings for all crops commonly grown in the country. Livestock – livestock production will be favoured during the year. Rain harvesting in form of field ponds should be encouraged especially in the north in order to avoid early livestock water starvation.”
On the issue of the possibility of spread of pests and diseases, Anuforom said farmers in the extreme north of the country and environs are likely to face attacks of grasshoppers (desert locust), flower-feeding insects, millet head miners and grain-eating birds (quela birds) and other environmental related crop diseases and called on the northern state governments to arrange for aerial spray of farmlands.
The mild–moderate harmattan season is predicted this year and because it may come with severe thunderstorms during onset periods of the rainy season, aviation activities within the year, coupled with pockets of severe weather activities are predicted during the critical periods of onset and cessation of rainfall may affect aviation operators and the flying public are advised to always avail themselves of weather advisories from NIMET prior to travels.
“On land transport, predicted rainfall pattern and associated severe rainstorms and strong winds which will occur in isolated areas will include poor visibility and slippery roads. Road users should take advise from the relevant government agencies such as NIMET and FRSC, etc. Also on coastal and maritime, rainstorms accompanied by strong winds may aggravate intensity of associated coastal flooding and erosion, resulting in landslide and loss of lives and properties. On the other hand, the 2012 prediction favour the likelihood of sufficient fish production in the coastal areas.
“On hydrology and water resources, the expected normal rainfall portends good prospects for the various hydrological areas of the country. Dam managers should always be on the alert as the rainfall may appear excessive in some areas due to other reasons, and the aftermath may be devastating.
On disaster management, flash flooding particularly in the northern states may result in property damage and loss of lives. Wet spells and flash floods can occur even in areas with a likelihood of normal rainfall.
“The Health sector is not exempted because there are likely incidences of increased air-borne diseases as a result of the harmattan dust haze early in the year, the predicted below normal temperature during the early part of the season may prevent heat waves.
Therefore, meningitis and malaria incidents may be less prevalent this year. Highest temperature recorded last year was 44.4DegC in Maiduguri. The lowest was 6.0DegC in Jos (Jan 12, 2011). 2011 was warmer than normal in most parts of the north and central states, southwest coast and parts of Delta state. Normal conditions prevailed in other parts,” he said.
Lack of preparedness and management on the part of both government and private establishment responsible for mitigating the effect often results casualties. Floods can be prevented with proper planning and adoption of effective mitigation measures in areas prone to flooding.