The formation and expansion of gullies have become one of the greatest environmental challenges bedeviling communities in Southern Nigeria today. From Lagos down to Calabar through Benin, Enugu to Port Harcourt through Umuahia and Owerri, the story is the same. The persistence increase in the size and number of this gullies across the South-East and South-South could be linked to some certain climatic conditions and environmental factors. The South-East and South-South states generally faces serious environmental challenges among which includes gully erosion menace which is affecting numerous communities and causing significant damages to infrastructure and land. This, some argued is due to the terrain and soil topography of the area which predominantly is of loose and sandy nature. Anambra state particularly has more than 100 gully erosion sites. These more than one hundred (100) active gully erosion sites with only a fraction under control is predominantly within the Aguata/Nnewi axis, – Umuchiana gully erosion site, Oko federal polytechnic, Ekwuluobia gully erosion site, Agulu-Ezechukwu, Agulu-Nanka, Enugu-Nanka Nnewichi gully erosion site in Nnewi LGA, Ozubulu erosion site in Ekwusigo LGA etc.
Aside Anambra state, other states severely devasted by the “hydra-headed monster” of gully erosion are Imo, Cross River, Akwa-Ibom and Abia states among others. Imo state alone has more than three hundred and fifty (350) active gully erosion sites. We will look at the effect of gully erosion on these states in our subsequent series
Gully erosion has led to several losses of lives and displacement of several communities in Nigeria, it is one of agriculture’s most potent enemy – a major environmental threat to sustainability and productivity with knock-on effects on the climate crisis and food security in Nigeria. This is particularly true for communities such as Agulu, Nanka, Ekwuluobia, Ozubulu and many more.
A Gully could be described as landform created by running water, mass movement, or both, which erodes sharply soil typically on a hillside or in a river floodplain or terraces, Gully erosion is a form of soil erosion where concentrated water flow cuts deep channels (gullies) into the soil, often separating land and causing significant environmental and economic problems
From several field studies conducted across the region, it was discovered that new gully sites were formed during each rainy season due to torrential rainfall, nature of underlying geology, high soil erodibility, and undulating topography that characterize the region as well as removal of vegetal cover due to several factors such as bush fire, illegal logging, urban encroachment and other anthropogenic factors. The massive soil loss in Southern Nigeria most especially in Imo, Anambra and Abia state caused by gully formation results in severe ecological damages, soil fertility depletion, considerable loss of soil structure, loss of lives, reduction of soil biodiversity, reduction in agricultural productivity, food insecurity, and disruption of socioeconomic activities, leading to untold hardship, pollution and contamination of surface water.
Gully erosion has swallowed up farms, homes, and roads in several parts of South eastern Nigeria. Among the places it swallowed up houses, farms and roads include Agulu, Nanka, Oko, Ozubulu. Ndiowu all in Anambra state, as well as Isukwuato, Ihechiowa, Amuzukwu in Umuahia North, and Ovom street in Aba, Ngodo, Amaokwe all in Abia State, ditto to Awo-Omamma, Mgbidi, Urualla, Orlu in Imo state.
The gully erosion in Nanka – one of the largest in Nigeria at 66 metres deep, 2,900 metres long and 349 metres wide, according to a recent study in the American Journal of Geographic Information System – is guzzling red earth from underneath people’s homes and farms, hence creating apprehension in the mind of people that their property may soon varnish.
From available record, the Nanka gully started forming around 1850, researchers say, and the regional soil erosion crisis has accelerated alarmingly in recent decades. It now threatens about 6,000 square kilometres or nearly six percent of Nigeria’s land mass, according to the World Bank.[
Climate change, which causes more intense downpours, is aggravating gully erosion by adding to other factors destabilizing soils such as deforestation, unsustainable farming, mining of sand for brick-making, road construction and poorly designed drains. As rainfall increases in intensity because of climate change, landslides become more common.
READ ALSO: Deforestation: The Imperative of Preserving Nigeria’s Forest Reserves
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, this is even more with a place with poor drainage system. According to statistics from World Resource Institute, the economic damage caused by gully erosion in the southeast is enormous and could be in excess of over one hundred million dollars (S100) annually.
There are several ways to curb the menace of gully erosion in Southern Nigeria. First and foremost, we should start with a decision to prevent the gully from coming into being in the first place. This could be achieved by proper enlightenment campaign aimed at dissuading citizens from exposing the soil surface to agents of erosion. Tree planting is acritical part of this endevour, desilting the water ways for a free flow of water, proper planning and execution of the drainage system, and timely reporting of any anomaly when the issue is at its infancy.
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 prevent hunger and mitigate the climate crisis.
Terraced farming could also be an effective strategy in both prevention and rehabilitation as it assists when implemented effectively, makes hillside agriculture manageable. Terraces prevent erosion and allow more water to flow to crops. In addition, hillside farm fields need full crop cover to help keep the soil in place. This can be accomplished by intercropping, which means growing two crops together in the same field, such as planting rows of maize or soybean between rows of oil palm trees. For smallholders, agroforestry systems where a diverse set of crops, including trees, are grown together can be effective. Access to manure improves the organic matter of the soil, which inhibits erosion. Finally, alternating deep-rooted and shallow-rooted crops improves soil structure and reduces erosion at the same time.
Arresting the menace of gully erosion can also be by offering Incentives for Land Management. Although the science of sustainable land management has been gaining support, the socio-economic context often makes implementation difficult. Sustainable land practices need to be financially viable for farmers. Anti-erosion measures could be expensive for the average farmer in Nigeria. Therefore, governments and banks can 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.
Tackling the menace of gully erosion in Nigeria of today can hardly be successful without the full support of the government. The truth is that the government has a very critical role to play. The government should strengthen laws that protect the environment, ensuring they are fair and consider the needs of vulnerable communities. This might involve updating laws on land ownership, pollution, and resource management. Government at both Federal and state level, should adopt frameworks to protect vulnerable groups, making sure they have access to a clean and healthy environment. These frameworks should also address past environmental wrongs, like erosion, pollution and flooding in certain areas. The government should enforce stricter regulations on industries that harm the environment, such as oil, mining, and agriculture, to ensure they follow sustainable practices. They should also invest in projects that impacts positively on the environment like waste management systems, renewable energy sources (e.g., solar and wind), and eco-friendly transportation to reduce environmental damage from urbanization and industrial growth. Support sustainable farming methods such as organic farming and agroforestry to prevent land degradation and improve food security in rural areas. Encourage the use of renewable energy, especially in rural areas, to reduce reliance on using firewood and charcoal and improve quality of life.
As for businesses, they need to be honest about their environmental impact and take responsibility for any harm they cause, including compensating affected communities. Companies can help restore forests and protect biodiversity by partnering with local communities. Through CSR, businesses can fund projects that benefit communities, such as clean water access and provision of clean and renewable energy for cooking. Businesses can fund initiatives that advocate for stronger environmental protections and promote environmental justice Local communities should have a say in environmental decisions that affect them. The government and businesses should hold regular consultations to listen to their views. Local leaders and governments should be involved in decisions related to land use, pollution control, and environmental management to ensure they reflect the needs of the people. Communities need to be educated about their environmental rights. Local leaders should be trained on environmental issues and sustainable practices.
In all these, enlightenment and education of the average citizen is paramount. This can be attained by utilizing public relations strategies such as workshops and seminars, town hall meetings, visitations, lobbying, demonstrations, stakeholders’ engagement, community gatherings etc to inform and educate local people about the dangers of erosion and how they can respond to it. Overall, achieving environmental justice in Nigeria requires coordinated efforts from the government, businesses, and local communities. By making sure vulnerable groups have a voice in decision-making and promoting sustainable development, Nigeria can work toward a more environmentally fair society. Collective action is key to overcoming environmental challenges and ensuring a better future for all.