The gully erosion menace in Southern Nigeria, particularly in Imo state has assumed a dimension that is unheard of in recent times, it has created several gullies big enough to swallow homes and other vital infrastructure. So many people have been rendered homeless due to the menace of gully erosion. It is on record that gully erosion has severe environmental, and socio-economic consequences, including loss of farmland, infrastructure damage, increased flooding, and displacement of communities.
Gully erosions occur due to sandy soil being unable to withstand the runoff and eventually eroding away, leaving gaping gullies that swallow homes and other infrastructure. Gullies and areas exposed to erosion in South Eastern Nigeria tripled from about 1.33% (1,021 km2) in 1976 to about 3.7% (2,820 km2) in 2006, making the region the most affected in the country.
There are several active gully erosion sites in Imo state despite the effort of the government in tackling the menace. It is estimated that there are more than three hundred and fifty (350) active gully erosion sites in the state currently with Ideato local government area alone accounting for a large percentage of this number. It is the same story in almost every local government area in Imo state. Close to the border with Anambra state is a community named Mgbidi which is the headquarter of Oru West LGA.
Mgbidi has several active gully erosion sites, but the ones so paramount is the ones on the Onitsha /Owerri express road which has been receiving government attention but yet to be tackled effectively. Less than ten kilometers from that Mgbidi gully is the Awo-Omamma active gully erosion site located towards the Njaba River. There are so many active erosion sites as well in this community. The nature of the community being predominantly hilly and sloppy has worsened the situation.
From investigations, there is no village in this town that does not have an active erosion site, but the ones that receive periodic attention are the ones on the Onitsha – Owerri express road toward the Njaba river.
Umuchima community in Ideato South LGA which is also in the Orlu senatorial area with Mgbidi and Awo Omamma was on the news not too far ago due to the danger of gully erosion. The community is still battling with the issue of the devastation of the gully erosion. Several hectares of fertile agricultural land have been lost to gully erosion in Umuchima community thus leading to decrease in crop yield and hence increase in food shortages.
In almost all the twelve LGA that make up the Orlu senatorial zone, there is no community that does not have one issue of gully erosion menace to contend with. From the border with Anambra state which is Oru – West and Orsu local government areas respectively down to Okigwe, which is a far more mountainous environment, gully erosion sites littered the terrain even up to Okigwe town itself.
In Owerri area, we have the following gully erosion sites: ugiri-ike, obohia, atta-ugiri-ike-obohia road ie the road linking Ikeduru and Ahiazu mbaise LGAs just to mention a few as we cannot enumerate all in this singular write-up particularly the ones in the urban center of Owerri North, Owerri West and Owerri Municipal.
Gully erosion also serves as an agent of deforestation, this is so because as the gully expands, it encroaches on the forested areas leading to deforestation and loss of biodiversity. It is also an enabler to flooding, because an increase to sedimentation in the rivers and waterways also leads to increased flooding, further damaging agricultural land and infrastructure.
This is the case with Njaba river, one of the two major rivers that serves as source to Oguta lake. The serious gully erosion at Awo – Omamma in Oru-East LGA leads to the massive washing away of topsoil which now is dumped into the river thereby filling up the river with debris and sand which has resulted to the shrinking of the river with its negative consequences to the environment.
Erosion. which is the process of soil and rock being removed from the Earth’s surface by natural forces such as wind, water, and ice, as well as human activities like deforestation and unsustainable farming could also lead to loss of soil and reduction in the soil’s water retention capability. Rill erosion, which is the initial phase of gully erosion reduces agricultural productivity, contributes to sedimentation in rivers and other water bodies, and leads to desertification.
Aside from these losses, gully erosion also leads to some serious socio-economic dislocations, damage roads, bridges, culverts and other infrastructure; impacting negatively on transportation and other economic activities.
Several people have been injured as a result of falling into the gully or being swept away by the floodwater. Deep and wide gullies can isolate communities, compelling people to relocate and leading to social unrest. In most cases people are forced to migrate from rural areas to the urban centers leading to socio- economic dislocation.
The destruction of agricultural farm land and infrastructure, couple with the displacement of people, result in significant economic loss. The combination of these factors can lead to increased poverty and food insecurity.
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Massive erosion of the topsoil that supports agriculture can exacerbate the effect of climate change. Climate change which is referred to as long-term alterations in temperature, precipitation, wind patterns, and other elements of the Earth’s climate system is primarily driven by the accumulation of greenhouse gases (GHGs), such as carbon dioxide (COâ‚‚), methane (CHâ‚„), and nitrous oxide (Nâ‚‚O), resulting from human activities like burning fossil fuels, deforestation, and industrial processes. Washing away of the fertile soil that supports vegetation can lead to increase in the amount of carbon dioxide since the vegetation that will capture the atmospheric ozone depleting gases such as carbon dioxide is depleted. This is also contributing to the increased temperature we are experiencing today. The consequences of climate change include rising global temperatures, melting ice caps, sea level rise, increased frequency of extreme weather events, and disruptions to ecosystems and agriculture.
Scientific evidence confirms that climate change poses a critical threat to biodiversity and human societies, necessitating urgent mitigation and adaptation measures.
There are several factors that contribute to the formation of gullies all over the south east among which include deforestation, industrialisation, urbanization and other human activities. A well-balanced environment supports biodiversity, provides essential resources for human survival, and maintains ecological equilibrium. However, human activities, such as deforestation, industrialization, and urbanization has led to increase in erosion menace and flooding which have significantly altered the natural ecosystems, leading to severe environmental challenges.
Understanding environmental concepts like erosion, and others such as desertification, pollution, flooding, drought and climate change is crucial for sustainable development and ecological preservation. Human activities have intensified these environmental challenges, making it essential to adopt mitigation and adaptation strategies to protect ecosystems and ensure environmental resilience.
Erosion itself is impacted by climate change. Climate change affects rainfall intensity and distribution, and an increase in rainfall intensity poses a serious erosion threat particularly in areas that are prone to erosion and most especially in places with poor drainage systems.
Persistent and heavy downpour exacerbate soil erosion especially in areas with sparse or no vegetation cover, most especially hilly or sloppy terrain.
Typical gully erosion sites in the south east
There are several ways to curb the menace of gully erosion in Southern Nigeria among which includes: Prevention and Rehabilitation-the key to managing and reducing soil erosion is to rehabilitate already-damaged land, stop further degradation and put erosion-preventative measures at the core of land management policy. In this way, we can help to mitigate the climate crisis.
Conservation techniques like afforestation, terracing, and sustainable farming practices help prevent erosion and restore degraded land. Another effective way of curbing the menace of gully erosion is by offering Incentives for Land Management and implementing anti erosion measures. The scientific strategies of sustainable land management can be very effective though it requires some financial muscle.
Therefore, governments and banks have to step in and assist farmers get access to credit and support in implementing erosion prevention. This is not only a good deal for the farmer, but for the whole community. The cost of erosion prevention is far lower than the price of land restoration and rehabilitation.
Gully erosion menace in Southern Nigeria will not go away in a hurry unless there is a synergetic effort to tackle it. The government – both federal state and local, organisations and the communities must work together in order to arrest the situation. Media organisations must bring the issue to the front burner. Environmental advocates must also up their ante. This way we will have a green and sustainable environment to live in and bequeath to the next generation.