Gully erosion

• [*] Major driver of global land degradation
• [<] Potentially undermine the efforts to realise nine of seventeen SDGs

Gully erosion

• The most violent form of land degradation
• Degrades fertile plains
• carves deep scars across landscapes
• swallows farmlands, road, buildings
• impacts food production and livelihoods
• Erosional channels with incisions several tens of meters into the soil, caused by surface and subsurface runoff.
• Distinct from other types of erosion, by virtue of its deeply erosive nature and attendant higher specific soil losses.
• unpredictable and dynamic in nature
• difficult to predict location where gullies are likely to form
• little scope for proactive or preventive management interventions

Reasons

• results of complex interplay between natural and human factors
• high population growth
• poor rangeland
• lack of vegetation cover
• over grazing
• intensive and short period rainfall
• poor irrigation design
• mismanaged water discharge
• soil characteristics
• frequent land use change weaken soil
• in urban areas, poor drainage and solid waste mismanagement
• climate change changing the rainfall pattern and intensity

Casualty

• topsoil is the biggest casualty, which once lost, takes decades to rebuild, sometimes centuries.
• in some cases, the lost top soil never recovers.
• Southern Nigeria, 37% of the area under severe gullies, soil loss of 10 tonnes per hectare per year
• Ethiopia, could have lost 1.5 million tonnes of topsoil, enough to grow 1.5million tonnes of grain

Extent of impact

• Red soils of eastern India to the savannahs of sub Saharan Africa
• 51 locations worldwide are identified as gully erosion affected areas, that led to disastrous consequence for human lives and properties.
• Worst affected countries include Nigeria, which is home to 15 out of 51 locations.
  • 90% of gully erosions stem from unchecked deforestation and poorly planned roads
• India, 77 districts in 28 states have unmanaged or active gullies.
  • Most of these are in eastern and southern India
  • Maximum gullies are found in Jharkhand, Chattisgarh, Madhya Pradesh, Rajasthan

Badlands

• Prolonged gully erosions results in deeply dissected landscapes, called Badlands
• This affects the agricultural productivity, water stress, droughts causing village abandonment

Targets for India

• Pledged to restore 26 million hectares of degraded land by 2030, as a part of its commitment to achieve Land Degradation Neutrality (LDN) under UN Convention to Combat Desertification (UNCCD)

Way forward

• Reactive land management practices after gully formation
• vegetation establishment
• applying soil and water conservation measures
  • check dams
  • gully plugging
  • runoff attenuation or diversion
• Prevent the removal of eroded sediment