Gully erosion is arguably the most violent yet overlooked form of land degradation. It carves deep scars across landscapes, severely degrades fertile plains and quite literally swallows farmland, roads and buildings, impacting food production and livelihoods. What’s worrying is that gully erosion is now a major driver of global land degradation, with impacts palpable from the red soils of eastern India to the savannahs of sub-Saharan Africa, and that it is getting exacerbated in the changing climate. In a paper published in Scientific Reports in February 2025, researchers estimate that gully erosion can potentially undermine efforts to realise nine of the 17 sustainable development goals (SDGs), specifically those related to zero hunger, clean water and sanitation and climate action.
Gullies are erosional channels, with incisions several tens of metres into the soil, caused by surface and subsurface runoff, states the Scientific Reports article. It explains that gully erosion is distinct from other types of erosion “by virtue of its deeply erosive nature and attendant higher specific soil losses” and has an unpredictable and dynamic nature. “The direct effects of gully erosion on societies bear close resemblance to that of landslides or subsidence,” says Anindya Majhi, geographer at University of Manchester, UK, and lead author of the article. Earlier in a 2022 paper published in Journal of the Geological Society of India, Majhi had identified 51 locations worldwide where gully erosion led to disastrous consequences for human lives and properties. Some of the worst affected countries include Nigeria, which is home to 15 of the 51 locations.
In India, Majhi records gully landforms in 19 of the 28 states and the National Capital Region of Delhi. At least 77 districts have unmanaged or active gullies that require urgent rehabilitative intervention, he states in the Scientific Reports article. Most of these districts are in eastern and southern India. The report identifies maximum gully erosion in Jharkhand and Chhattisgarh, followed by Madhya Pradesh and Rajasthan. At places, gully erosions have forced abandonment of entire villages. Prolonged gully erosions produce deeply dissected landscapes known as “badlands”, which then affect the agricultural productivity, water stress and droughts causing village abandonment, says Majhi. This can be a major impediment for India, which has pledged to restore 26 million hectares of degraded land by 2030 as part of its commitment to achieve Land Degradation Neutrality (LDN) under UN Convention to Combat Desertification.
Gully erosion is the result of a complex interplay between natural and human forces. “The major driving forces are high population growth, poor rangeland, lack of vegetation cover, overgrazing, intensive and short-period rainfall, poor irrigation design, mismanaged water discharge and soil characteristics,” writes Getahun Hassen from Dilla University in Ethio-pia in a 2020 article in Geoenvironmental Disasters. Frequent land-use changes weaken soils, making them more vulnerable to flooding. Majhi shares that in Nigeria, 90 per cent of the gully erosions stem from unchecked deforestation and poorly planned roads. In urban areas, gully erosion is often worsened by poor drainage and solid waste mismanagement. “Municipal solid wastes find their way into gullies, blocking channels and acting as a ‘sponge’, rubbing against gully walls during floods and causing more devastating erosion,” highlights a 2023 study by Pan African University of Life and Earth Sciences Institute, Nigeria.
Climate change adds another layer of complexity to gully erosion, says Ryan Anderson, lecturer at the Department of Geography at the University of South Africa, Pretoria. “Changes in rainfall regimes may cause more intense storms, coupled with longer dry spells. This enhances gully erosion at places with reduced vegetation,” he says.
The biggest casualty of gully erosion is topsoil, which, once lost, can take decades—even centuries—to rebuild. In many cases, the land never recovers. Studies in southern Nigeria show 37 per cent of the area under severe gullies see a soil loss of 10 tonnes per hectare per year. Hassen, who has analysed 12 gullies in Ethiopia, estimates that the areas could have lost 1.5 million tonnes of topsoil—enough to grow 1.5 million tonnes of grain.
Mitigating existing gullies can be challenging and costly. It is also difficult, though not impossible, to predict locations where gullies are likely to form. Therefore, there is little scope for proactive or preven tive management interventions.
Majhi thus proposes reactive land management practices after gully formation, which may include vegetation establishment, applying soil and water conservation meas ures like check dams, gully plugging, runoff attenuation and/or diversion. However, appropriateness of a given management intervention would depend on the local runoff characteristics and gully cross-sectional stability.
Anderson says, “The big win with gully erosion is to prevent the removal of eroded sediment. That way, a new wetland can form—helping rehabilitate the land and support fresh vegetation, which will also help stabilise the gully.”
This article was originally published in the May 1-15, 2025 print edition of Down To Earth