Anthropogenic Geomorphology: Terminology for UPSC Geography Optional

Anthropogenic geomorphology treats human beings as a geomorphic agent that digs, piles, dams, drains, paves and mines the land faster than most natural processes. This post covers how people change landforms and processes; how landforms and processes affect people and planning is environmental geomorphology. The terms here are increasingly examined through Indian mining, subsidence and river cases.

Read each entry definition first, then mechanism, impacts and examples. UPSC asked scarification directly in 2026. Joshimath (2023), Jharia, Aravalli quarrying and the 2024 decision on the Anthropocene are the current examples most likely to strengthen any answer on human impact.

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Humans as a Geomorphic Agent

Anthropogenic geomorphology (anthropogeomorphology)

Anthropogenic geomorphology is the branch of geomorphology that studies human beings as a geomorphic agent. It covers the landforms people create directly by excavation, construction and water engineering, and the natural processes of erosion, deposition, mass movement and subsidence that human activity accelerates, slows or redirects.

• Origin: George Perkins Marsh‘s Man and Nature (1864) first set out human alteration of the earth’s surface; Robert Lionel Sherlock‘s Man as a Geological Agent (1922) argued that in England human denudation already outpaced natural denudation; the 1955 Princeton symposium “Man’s Role in Changing the Face of the Earth” made the theme international.
• Key features: humans now move far more sediment than rivers do. A 2018 British Geological Survey-led study put human sediment production at about 316 billion tonnes a year, some 24 times the sediment delivered to the oceans by the world’s rivers. A 2022 satellite survey mapped 101,583 km² of land under mining worldwide.
• Types: planned (intentional) and inadvertent effects; direct and indirect processes (next entry).
• Examples: the Rhenish lignite district of Germany; in India, the coal belt of the Damodar valley and the quarried Aravallis.
• Don’t confuse with: environmental geomorphology, which reads the reverse direction — nature’s effects on people.

Anthropogeomorphic processes (direct & indirect)

Anthropogeomorphic processes are geomorphic processes set in motion by human activity. They are direct when people themselves move earth or water (digging, dumping, damming, dredging), and indirect when human action changes the conditions under which natural processes operate, so that erosion, slope failure or subsidence follow.

• Types (direct): excavation (mining, quarrying, cutting, dredging), construction (tipping, embanking, terracing, landfill) and hydrological interference (damming, canalisation, drainage, channel straightening). This scheme was popularised by Andrew Shaw Goudie.
• Types (indirect): accelerated erosion and sedimentation, subsidence, slope failure, altered weathering from polluted air, and earthquakes triggered by reservoirs (see reservoir-induced seismicity).
• Key features: indirect effects are delayed, cumulative and often far from their cause, which makes them harder to regulate.
• Examples: hill-road cutting in Uttarakhand and Himachal Pradesh (direct) followed by repeated slope failures along the cuts (indirect); deforestation in the Himalayan foothills raising river sediment loads downstream.

Anthropogenic landforms (excavational, constructional & hydrological)

Anthropogenic landforms are landforms made, or deliberately reshaped, by people. They are classified as excavational (hollows cut into the ground), constructional (material piled up) and hydrological (landforms created by controlling water).

• Types: excavational — quarries, opencast pits, road and rail cuttings, borrow pits, canals, tanks, craters; constructional — spoil heaps, landfills, embankments, dams, terraces, reclaimed land, archaeological mounds; hydrological — reservoirs, polders, drained marshes, canal networks.
• Key features: they usually have sharp breaks of slope and unconsolidated, poorly drained materials, and are prone to settlement and failure.
• Examples: Sophienhöhe, a spoil hill rising about 200 m above the plain beside the Hambach mine, Germany; the Ghazipur landfill of Delhi, over 60 m high; the tank systems of the Deccan; agricultural terraces of the Garhwal Himalaya.
• Sketch: a profile showing a cutting, an embankment, a spoil heap and a reservoir, each labelled by class.

Mining, Scarification and Subsidence

Scarification (land scarification)

Scarification, in geomorphology, is the scarring of the land surface by direct human excavation and removal of rock and soil. It is produced by quarrying, opencast and strip mining, road and rail cuttings, borrow pits and brick-clay pits, and leaves pits, benches, highwalls and spoil dumps where natural relief once stood. It is the most intense form of direct anthropogenic landform change.

• Don’t confuse with: in agronomy and forestry, scarification means loosening or scratching the soil surface (or a seed coat) to aid germination or tree regeneration. That shallow, beneficial tillage is not the geomorphic meaning.
• Mechanism: overburden is stripped, rock blasted and waste dumped; drainage is cut and the pit floor becomes a new local base level.

Impacts on land

• Relief and slope change: in central Appalachia (USA), a 2016 study found mountaintop removal had lowered median slope by nearly 10° and dumped over 6.4 km³ of broken bedrock into 1,544 valley fills, burying more than 1,000 km of headwater streams.
• Drainage disruption: streams are buried or diverted, pits become lakes and springs dry up.
• Spoil failure: saturated dumps slide — the Aberfan tip disaster, Wales (21 October 1966), killed 144 people.
• Acid mine drainage: oxidising pyrite acidifies streams, as in Meghalaya’s Jaintia Hills coal areas.
• Soil loss: topsoil and seed banks go outright; reclamation restores cover more often than form.

Examples

• Indian: Jharia (Jharkhand) and Talcher (Odisha) coalfields, dominated by opencast pits and overburden dumps. In the Aravallis, the Supreme Court noted in October 2018 that 31 hills in Rajasthan had vanished through illegal mining; a 100-metre relief test for protected hills, adopted in November 2025, was stayed on 29 December 2025. In the Bellary (Ballari) iron-ore belt, mining was suspended by the Supreme Court in July 2011. In the Western Ghats, Kerala had 5,924 working stone quarries in 2018, only 750 of them with permits.
• Global: Appalachian mountaintop removal; the Rhenish lignite mines, where the Hambach pit reaches 299 m below sea level; the Athabasca oil sands, where about 895 km² of Alberta’s 4,800 km² of surface-mineable area had been disturbed by 2013.
• Sketch: before-and-after profiles of a ridge — the original convex ridge and V-notch stream, then a pit with highwall, benches, pit lake and an external overburden dump burying the valley.

Open-cast mining landforms & spoil heaps

Open-cast mining landforms are the pits, stepped benches, vertical highwalls, haul-road ramps and flooded voids left by surface mining. Spoil heaps (overburden dumps) are the constructional counterparts: mounds of waste rock and soil stripped from above the ore or coal and tipped inside or beside the pit.

• Formation: overburden is removed in strips or benches; internal dumps backfill mined-out areas, external dumps rise on unmined land; tailings from ore processing are stored behind earth dams.
• Key features: dump slopes stand near the angle of repose and gully rapidly; tailings dams can fail catastrophically — at Brumadinho, Brazil (25 January 2019), a tailings dam collapse killed about 270 people.
• Examples: Gevra opencast coal mine (Chhattisgarh), among the largest in Asia; the Singrauli coalfield on the Madhya Pradesh–Uttar Pradesh border; in India more than 90 per cent of coal now comes from opencast mines.
• Significance / Hazard link: dumps shed sediment into rivers such as the Damodar and fill reservoirs downstream.

Human-induced land subsidence (groundwater mining; Joshimath 2023)

Human-induced land subsidence is the lowering of the ground surface caused by human activity. It results mainly from pumping groundwater, oil or gas faster than it is replaced, which lets fine sediments compact, and also from surface loading, poor drainage and wetting of unstable ground. It is usually slow but irreversible once clays compact.

• Mechanism: pore-water pressure supports the grains of an aquifer system; pumping reduces that pressure, clay layers squeeze out water and compact permanently, and the surface sinks.
• Examples (groundwater): Mexico City and northern Jakarta have sunk by tens of centimetres a year at the worst points. In Delhi, satellite radar found Kapashera, near the airport, subsiding by over 11 cm a year during 2014–2020, while Dwarka, with rainwater recharge, rose slightly.
• Joshimath (Uttarakhand): the town stands on thick old landslide and glacial debris, a hazard flagged in the 1930s and by the Mishra Committee (1976). The 1976 committee warned against heavy construction, blasting and deforestation. National Remote Sensing Centre radar data showed about 9 cm of subsidence between April and November 2022, then 5.4 cm in the 12 days from 27 December 2022 to 8 January 2023, after water burst from the slopes on 2 January 2023. The official post-disaster assessment, made public in 2023, blamed mainly inadequate drainage: soak pits in most homes and leaking pipes saturating the debris under growing building loads. The role of the Tapovan–Vishnugad hydropower tunnel remains disputed and was not established.
• Significance / Hazard link: cracking of buildings, broken pipes, loss of aquifer storage and higher flood risk. Natural subsidence is covered under natural land subsidence.

Mining subsidence & coal-fire subsidence (Jharia)

Mining subsidence is the collapse or sagging of the ground surface over underground mine workings when roof rock and pillars fail. Coal-fire subsidence occurs where coal seams burn underground and the burnt-out void collapses. The two often combine in old coalfields.

• Types: pit (crown-hole) subsidence over shallow, room-and-pillar workings; trough subsidence over longwall panels; fire-induced cracks and vents.
• Mechanism: abandoned pillars weather and crush; oxygen entering through cracks sustains smouldering fires, which widen voids and cracks further.
• Examples: Jharia coalfield (Dhanbad, Jharkhand), where fires were first recorded in 1916. Scientific control cut fire sites from 77 to 27 and the affected area from 17.32 km² to about 1.80 km², and the Union Cabinet approved a revised Jharia Master Plan worth ₹5,940.47 crore on 25 June 2025. The Raniganj coalfield (West Bengal) also has subsidence-prone settlements; Centralia, Pennsylvania, has burned since 1962.
• Sketch: a cross-section with seam, pillars, a burning zone, collapse void and a surface crown hole under houses.

Hydrocompaction

Hydrocompaction is the sudden settlement of dry, low-density sediments such as loess, mudflow-deposited fan sediments or collapsible silts when they are wetted for the first time. Water weakens the clay bonds holding the open grain framework together, and the deposit collapses.

• Mechanism: irrigation water, leaking canals or ponds wet a deposit that has never been saturated; its volume drops abruptly.
• Key features: cracks, sinks and sags appear along new canals and fields within months of irrigation starting.
• Examples: the west side of the San Joaquin Valley, California, where canal and field irrigation caused local subsidence of up to several metres.
• Significance / Hazard link: damage to canals, well casings, roads and pipelines in newly irrigated drylands.

Human-induced sinkhole (mine-dewatering sinkholes)

A human-induced sinkhole is a collapse depression formed when human lowering of the water table, by mine dewatering or heavy pumping, removes buoyant support from the cover over cavities in limestone or dolomite. Without that support, the overlying soil caves into the voids.

• Mechanism: dewatering drains solution cavities; unconsolidated cover loses support and ravels downward until the surface suddenly collapses.
• Examples: the Far West Rand gold field near Johannesburg, where dewatering in dolomite triggered sinkholes in the 1960s. The West Driefontein collapse of December 1962 swallowed a crusher plant and killed 29 people. Pumping-induced sinkholes are also common in central Florida.
• Don’t confuse with: natural solution and collapse dolines, which form without human interference — see sinkholes.

Human Impact on Erosion and Rivers

Accelerated (anthropogenic) erosion vs geological erosion

Geological (normal) erosion is the slow, natural rate of denudation that is roughly balanced by soil formation under natural vegetation. Accelerated erosion is erosion raised above that background rate by human activity — clearing, cultivation, grazing, construction and mining — so that soil is lost faster than it forms.

• Key features: accelerated erosion can exceed natural rates by one to three orders of magnitude on bare construction and mine sites; it is most severe in monsoon, semi-arid and Mediterranean lands.
• Examples: a widely used 1983 estimate put India’s soil erosion at about 5.3 billion tonnes a year; ISRO’s Desertification and Land Degradation Atlas (2021) placed 97.85 million hectares, 29.7 per cent of India, under land degradation in 2018–19.
• Significance / Hazard link: loss of fertility, silting of rivers and reservoirs, and raised flood beds.
• Don’t confuse with: denudation in general, which includes weathering and mass movement.

Man-induced soil erosion (gully erosion)

Man-induced soil erosion is soil loss triggered or intensified by human land use. Its most destructive form is gully erosion, in which concentrated runoff from cleared, overgrazed or badly ploughed land cuts steep-sided channels too deep to be removed by normal tillage.

• Mechanism: clearing removes interception and root binding; hoof trampling and machinery compact the soil; up-and-down ploughing, cattle tracks and road drains concentrate runoff, which cuts rills that deepen into gullies by headcut retreat. The mechanics of rill and gully growth are covered under rills and gullies.
• Examples: the Chambal, Yamuna and Mahi ravine belts (their badland landforms are covered under ravines and badlands); the Loess Plateau of China, where terracing, check dams and the Grain for Green programme (from 1999) have cut erosion sharply.
• Significance / Hazard link: loss of farmland and the need for gully plugging, contour bunding and afforestation.

Channelisation & river training (embankments, spurs, revetments)

Channelisation is the artificial modification of a river channel by straightening, deepening, widening or lining it. River training uses structures — embankments (levees), spurs (groynes), revetments and guide bunds — to fix a river’s course, protect banks and pass floods quickly.

• Mechanism: cutoffs shorten the course and steepen gradient, causing incision upstream and deposition downstream; embankments confine sediment, so the bed aggrades and the river may come to flow above its floodplain.
• Examples: the Kosi embankments of Bihar (built from the 1950s), where aggradation between the levees preceded the Kusaha breach of 2008 (see avulsion); the nineteenth-century rectification of the Upper Rhine, which shortened it by about 80 km; artificial cutoffs on the lower Mississippi in the 1930s.
• Don’t confuse with: coastal defences such as sea walls and groynes — see coastal protection structures.

Dams, reservoir sedimentation & sediment trapping

Reservoir sedimentation is the progressive filling of a reservoir by sediment carried in by the river, because a dam cuts flow velocity and traps most of the bed load and much of the suspended load. Sediment trapping is the resulting interruption of the natural sediment supply to the channel, delta and coast downstream.

• Mechanism: deltas build at the head of the reservoir and fine silt settles near the dam; clear water released downstream (“hungry water”) erodes the bed and banks.
• Key features: a 2005 global synthesis estimated that human activity has raised river sediment transport by about 2.3 billion tonnes a year through soil erosion, while reservoirs hold back about 1.4 billion tonnes a year from the coast, with over 100 billion tonnes already stored behind dams.
• Examples: the Aswan High Dam (completed 1970) trapped almost all Nile sediment, and the Nile delta coast has retreated since; in India, Central Water Commission surveys repeatedly find large reservoirs losing capacity faster than their designs assumed.
• Significance / Hazard link: loss of storage, turbine abrasion, delta subsidence and coastal erosion.

Sediment yield

Sediment yield is the total quantity of sediment leaving a drainage basin (or a unit area of ground) in a given time, usually expressed in tonnes per square kilometre per year. It measures net erosion after deposition within the basin, and it is the key index of human impact on catchments.

• Key features: the sediment delivery ratio is the share of eroded material that actually leaves the basin, and it falls as basin size increases. Yield rises with relief, rainfall intensity, weak rocks and land disturbance.
• Examples: the Yellow River once carried about 1.6 billion tonnes a year from the loess uplands; dams and soil conservation have since cut its load by around 90 per cent. The Ganga and Brahmaputra together still deliver among the largest sediment loads in the world.
• Don’t confuse with: sediment load (what a river carries at a station) — see stream load.

Sand mining (in-channel sand and gravel extraction)

Sand mining is the extraction of sand and gravel from river beds, banks, floodplains, beaches and the seabed for construction. Removal faster than the river replaces it creates a sediment deficit that lowers the bed and destabilises the channel.

• Mechanism: extraction pits trap incoming bed load and propagate a knickpoint upstream and a scour wave downstream; the bed lowers, banks collapse, and the water table beside the river falls.
• Key features: sand and gravel, at about 50 billion tonnes a year (UNEP, 2022), are the most extracted solid materials after water.
• Examples: bed lowering, saline intrusion and dry wells along the Periyar and Bharathapuzha rivers of Kerala; the collapse of the Hintze Ribeiro bridge in Portugal (4 March 2001, 59 deaths), blamed on sand extraction undermining its piers. India issued Sustainable Sand Mining Management Guidelines in 2016 and enforcement guidelines in 2020.

Urban and Coastal Landscapes and the Anthropocene

Urbanisation and runoff (urban flooding)

Urbanisation and runoff refers to the way that paving, roofs and drains convert infiltrating rain into fast surface runoff. This raises flood peaks, shortens the time lag between rainfall and peak discharge and reduces groundwater recharge. Urban flooding is the result when drainage capacity and natural storage are overwhelmed.

• Mechanism: impervious cover cuts infiltration; storm sewers deliver water quickly to channels; building over lakes, marshes and floodplains removes storage.
• Key features: the flood hydrograph becomes higher and narrower; channels enlarge and erode in the early years of construction.
• Examples: Mumbai on 26 July 2005, when about 944 mm of rain fell in 24 hours at Santacruz and the encroached Mithi river overflowed; Chennai in December 2015, with built-over lakes and the Pallikaranai marsh; Bengaluru in September 2022, after lake beds and drains were encroached.
• Don’t confuse with: urban geomorphology as a planning tool — see urban geomorphology.

Land reclamation (coastal & wetland reclamation)

Land reclamation is the creation of new dry land from sea, estuary, lagoon, marsh or lake. It is achieved by enclosing and draining areas behind dykes (poldering) or by filling them with dredged sand, rock and waste, and it builds some of the largest anthropogenic landforms.

• Types: poldering (enclosure and pumping), infilling with dredged or quarried material, and wetland drainage for farming or building.
• Key features: fill settles and may liquefy in earthquakes; tidal prisms, currents and sediment paths change; mangroves and fisheries are lost.
• Examples: the Netherlands’ Zuiderzee Works and Flevoland polders; Singapore, which has grown from about 580 km² in the 1960s to over 720 km²; Mumbai, where the original seven islands were joined by reclamation; Bidhannagar (Salt Lake City), Kolkata, built in the 1960s over the eastern wetlands; Willingdon Island, Kochi, raised from harbour dredging.
• Significance / Hazard link: reclaimed coasts are among the most exposed to storm surge and sea-level rise.

Anthropocene

The Anthropocene is a proposed unit of geological time marking the interval in which human activity has become the dominant force altering the earth’s surface, atmosphere, oceans and biosphere. The term is widely used informally, but it is not a formal epoch of the geological time scale.

• Coined by: popularised by the atmospheric chemist Paul Jozef Crutzen in 2000.
• Proposal: the Anthropocene Working Group proposed a start in the early 1950s, marked by plutonium fallout and other signals, with a reference section (GSSP) in the sediments of Crawford Lake, Ontario, Canada.
• Decision: in a vote announced in March 2024, the Subcommission on Quaternary Stratigraphy rejected the proposal (12 against, 4 in favour, 2 abstentions), and the International Union of Geological Sciences confirmed the result on 20 March 2024. The Holocene, with its Meghalayan Age, remains the current formal unit (see Holocene).
• Current debate: many geoscientists now propose treating the Anthropocene as a geological event — diachronous, like the Great Oxidation Event — rather than an epoch with a single start date.
• Significance: the geomorphic evidence remains unchanged by the vote. Human earth-moving, sediment trapping and mining footprints are measurable whether or not the unit is formalised.

PYQs Built on These Terms

• What is scarification? List out various impacts and examples of scarification on land. (2026)

Frequently Asked Questions

What does scarification mean in geography?

In geography and geomorphology, scarification means scarring the land surface by human excavation: quarrying, opencast and strip mining, road cuttings and borrow pits, which leave pits, benches, highwalls and spoil dumps. In agriculture and forestry the same word means loosening the soil surface to help seeds germinate, a different and shallow activity.

What caused the Joshimath land subsidence in 2023?

Joshimath sits on old landslide and glacial debris that was always unstable. The official post-disaster assessment blamed mainly poor drainage: wastewater from soak pits and leaking pipes saturated the debris, while building loads kept growing. Satellite radar recorded 5.4 cm of sinking in 12 days in early January 2023. The hydropower tunnel’s role remains disputed.

Is the Anthropocene an official geological epoch?

No. In March 2024 the Subcommission on Quaternary Stratigraphy voted 12 to 4, with 2 abstentions, against making the Anthropocene a formal epoch beginning in the 1950s. The International Union of Geological Sciences confirmed this on 20 March 2024. The term remains in wide informal use, and some geologists now call it an “event”.

What is the difference between accelerated erosion and geological erosion?

Geological erosion is the natural background rate, slow enough to be balanced by soil formation under natural vegetation. Accelerated erosion is the higher rate caused by human activity such as deforestation, overgrazing, faulty ploughing, construction and mining, which strips soil faster than it forms and delivers extra sediment to rivers and reservoirs.

How do dams affect rivers downstream?

A dam traps most of a river’s sediment in its reservoir and releases clear, sediment-hungry water. Downstream, the channel erodes its bed and banks, deltas and beaches lose supply and retreat, and floodplains stop receiving fresh silt. Upstream, the reservoir itself slowly fills, losing storage capacity over decades.

Why is Jharia burning and sinking?

Jharia’s coal seams lie close to the surface and were heavily worked by room-and-pillar mining. Air entering through cracks and old workings started fires, first recorded in 1916, which widen voids until the ground collapses. Control measures have cut fire areas sharply, and a revised rehabilitation master plan was approved in June 2025.