Nigeria is likely one of the most flood-prone international locations in west Africa. Many areas expertise annual flooding. This occurs throughout heavy rainfall and one of many causes is poor drainage programs.
The nation due to this fact must make enhancements. As researchers who’ve specialised in meteorology for about 20 years we consider there are a number of methods it may well do that. The important thing interventions wanted are:
understanding the impression of local weather change on rainfall extremes and water sources
investing in a purposeful climate forecast system
addressing the issue of poor drainage.
These actions are vital to construct resilience to floods.
The Nigeria Meteorological Company and the Nigeria Hydrological Companies Company have predicted extreme flooding this 12 months. And up to date devastating flooding incidents are nonetheless recent within the minds of Nigerians.
Flooding in Nigeria
Flash floods are thought of the deadliest hazards associated to excessive climate. Nigeria is more and more vulnerable to them.
There are numerous predictors of floods, chief of which is more and more heavy rains over the west African Sahel.
In current many years components of Nigeria have skilled summer season rainfall extremes which are extra intense than earlier than. Even dry areas just like the Lake Chad River basin have begun to have file rainfalls. Downpours have submerged land areas, overrun watersheds and threatened the carrying capability of water reservoirs.
That is anticipated to worsen because of international warming, in response to a current scientific examine by the World Climate Attribution scientific crew.
The atmospheric rivers linked to the current heavy rainfall over the area are related to a hotter north Atlantic and Mediterranean. The warming is related with sea floor temperature anomalies within the tropical Pacific Ocean, described as Trans-Atlantic-Pacific Ocean Dipole.
Research have additionally proven that La Niña occasions, periodically cool ocean floor temperatures within the central and east-central equatorial Pacific. The cooling is coupled with adjustments in winds and strain that trigger elevated rainfall over the west African Sahel. Extra disturbing is the uncommon “triple-dip” La Niña local weather occasion. Three consecutive years of those occasions will set off extra rainfall than regular in some areas.
The second set of drivers is geographical. For instance low-land and coastal areas are flood threat areas due to rising river ranges. Earlier flood disasters have proven that these areas are catastrophe inclined.
Thirdly, flooding in Nigeria is made worse by the poor administration of drainage programs. The mix of heavy rains and nonexistent or poor drainage system will increase the probability of flash floods in cities.
Including to the issue are poor waste disposal, poor city planning, tarmacking of city roads and building of drainage programs with out local weather adaptation in thoughts.
Constructing resilience in opposition to floods
There’s no approach to affect rainfall variability, particularly within the quick time period. However inexperienced engineering will help shield people and the surroundings.
There are two methods that Nigeria can simply use. They’re correct dam administration and tree planting. These initiatives will scale back the pace of water stream and scale back the impression of floods.
One other simple intervention is the method of threat mapping, evaluation and planning for floods. This informs how sources ought to be distributed and scale back threat. It has been profitable in international locations resembling Romania and Bulgaria.
Then there may be forecasting. It’s a complicated course of that’s frequently being improved as synthetic intelligence and machine studying are integrated into the prediction applied sciences. Capability constructing is required to enhance the reliability of forecasting within the nation.
Each the Nigeria Hydrological Companies Company and the Nigerian Meteorology Company present well timed precipitation forecasts for water-related catastrophe administration. The World Meteorological Organisation has supported forecasting companies in west Africa by means of its Extreme Climate Forecasting Demonstration Mission. The mission could be extra helpful if it operated in all meteorological centres throughout the nation.
For climate forecasting to ship high quality information, there’s a must constantly put money into tools and evaluate efficiency. As an illustration, the NigeriaSat-2 was constructed to present high-resolution imagery of the Earth’s floor however it’s previous its design life.
Drainage programs will be developed and improved by channels or ditches, and piping that directs extra rainwater and sewage to a degree of disposal. Sustainable city drainage programs have gotten widespread given their a number of advantages resembling lowering the results of air pollution.
Lastly, financing has stood out as a problem. Nigeria’s authorities must make good use of the local weather change loss and harm fund that was established on the COP27 assembly. Entry to the funding will depend on having programs for information assortment, recording and reporting of loss and harm finance wants.
Avoiding a repeat of catastrophe
Previous floods are nonetheless recent in folks’s minds. In 2012, the harmful impact of the surplus water launched from the Lagdo Reservoir in northern Cameroon and torrential summer season rainfall killed 400 folks, displaced hundreds of thousands of others, and destroyed over 152,575 hectares of farmland in Nigeria. The Nigerian Emergency Administration Company) estimated a complete financial loss to be about US$16.9 billion.
In 2022, the flooding precipitated over 600 deaths and affecting an estimated 3.2 million folks throughout 34 of the nation’s 36 states. The floods destroyed over 569,251 hectares of farmland.
Because the 2023 flooding approaches, it will be important for federal authorities and state companies to work in coordination, following the seasonal local weather forecast updates issued by the Nigerian Meteorological Company. As a matter of urgency, states ought to arrange native catastrophe administration committees to help in creating consciousness and relocating communities residing in flood-prone areas.