Maarg Manthan · Topic 10.13

Soil Erosion and Problems Due to Excessive Irrigation

Environment & Ecology › Land, Forest and Soil Resources · Topic 10.13

Soil erosion is the detachment and removal of soil particles by water, wind, ice or gravity. Natural or geological erosion is slow and balanced by soil formation, while accelerated erosion caused by deforestation, overgrazing, ploughing along slopes and construction is far faster than formation. Water erosion appears as splash, sheet, rill and gully erosion, and in extreme cases as ravines such as the Chambal; wind erosion moves particles by saltation, suspension and surface creep, mostly in arid zones like the Thar. Excessive or poorly managed irrigation causes its own problems: waterlogging when the water table rises into the root zone, salinisation and alkalinisation as evaporation leaves salts at the surface, groundwater depletion, nutrient leaching, siltation of canals, and soil compaction. Canal command areas in Punjab, Haryana, Rajasthan, Uttar Pradesh and Maharashtra show these effects clearly.

5 min read · UPSC Prelims · Environment & Ecology · Land, Forest and Soil Resources

At a Glance

Agents Water, wind, ice, gravity
Water types Splash, sheet, rill, gully
Ravines Chambal
Irrigation issues Waterlogging, salinity
Affected areas Canal commands
Exam link UPSC Prelims, Environment & Ecology: Land, Forest and Soil Resources

Where Does It Fit?

This topic follows the account of soil types and shows how soils are lost and damaged. It leads to the measures for conservation and the soil health scheme. Previous topic: regur USDA orders Twelve Best for rice, wheat Alluvial Exam…">Types of Soils in India and the World. Next topic: Soil Conservation Measures.

What Are the Types of Soil Erosion?

Type	Description
Splash erosion	Raindrops hit bare soil, break aggregates and splash particles
Sheet erosion	Thin layer of topsoil removed evenly by runoff; hard to notice but removes fertile soil
Rill erosion	Many tiny channels cut by flowing water on a slope
Gully erosion	Deep channels cut by concentrated runoff; badlands and ravines like the Chambal result
Stream bank erosion	Rivers cut and collapse banks
Wind erosion	Dry, loose soil moved by saltation (bouncing), suspension (fine dust) and surface creep (rolling), as in Thar
Mass movement	Landslides and soil creep on steep, wet slopes

What Problems Does Excessive Irrigation Cause?

Waterlogging: water table rises, pores fill with water, roots lack air and crops fail
Salinisation: salts left behind by evaporating water build up on the surface
Alkalinisation: sodium builds up, making soil hard, sticky and high in pH
Groundwater depletion: heavy pumping lowers water tables in Punjab, Haryana and western Uttar Pradesh
Nutrient leaching: excess water carries nitrates downward into groundwater
Canal siltation and seepage: unlined canals lose water and raise water tables
Soil compaction: wet soil is damaged by machines
Irrigation-induced erosion: furrow irrigation on slopes washes soil away

What Else Should You Remember?

Geological erosion: slow natural erosion balanced by soil formation
Accelerated erosion: human-induced and far faster than formation
Causes of water erosion: heavy rain, steep slopes, bare soil, deforestation and downslope ploughing
Raindrop impact: rain on bare soil has a strong effect on erosion
Chambal ravines: cover large areas in Madhya Pradesh, Rajasthan and Uttar Pradesh, formed by gully erosion in alluvium
Badlands: heavily gullied land unfit for farming
Wind erosion zones: Rajasthan, Gujarat, Haryana and parts of Punjab
Sand dunes: move by wind and can bury farm land
Estimated loss: a widely cited estimate puts annual soil loss in India at about 5.3 billion tonnes, but newer studies differ
Effects of erosion: loss of fertility, siltation of dams, floods, and sediment pollution of rivers
Reservoir siltation: reduces storage capacity of dams
Reh, kallar, usar: local names for saline and alkaline soils in the northern plains
Saline soil: high soluble salts, white crust, reduces water uptake by plants
Alkaline soil: high exchangeable sodium, dispersed clay, poor structure
Drainage: proper drainage and leaching are needed to manage salts
Gypsum: added to alkaline soil to replace sodium
Canal command effects: Indira Gandhi Canal, Sharda Sahayak and Tungabhadra commands show waterlogging and salinity
Flood irrigation: wasteful compared with drip and sprinkler systems
Water use efficiency: micro-irrigation under PMKSY aims for more crop per drop
Crop choice: water-intensive rice and sugarcane in dry zones worsen groundwater and soil problems
Conjunctive use: combine surface and groundwater to keep water tables safe
Link to previous: see Types of Soils in India and the World
Link to next: see Soil Conservation Measures
Link to land degradation: see Causes and Impact of Land Degradation
Caution: soil loss estimates vary by method; quote as an approximate and cite the source
Exam hint: learn erosion types in order and the three irrigation-linked problems
Over-irrigation: applying more water than crops need wastes water, leaches nutrients and often raises the water table
Vegetation role: plant roots bind soil, leaves cushion rain, and litter slows runoff, so bare land erodes fastest
Terrace failure: poorly built or unmaintained terraces and bunds can collapse and start gullies
Himalayan erosion: steep slopes, road building and deforestation drive landslides and heavy sediment loads in Himalayan rivers
Coastal erosion: waves and sea level rise remove coastal soil and beaches, which is a different process from farm soil erosion

Why Does It Matter for the Exam?

Water types: Splash, sheet, rill, gully
Ravines: Chambal
Irrigation issues: Waterlogging, salinity
Current affairs link: Micro-irrigation
Common errors: confusing saline and alkaline soils or sheet and rill erosion

As an analytical point, erosion and irrigation damage are two faces of poor land and water management. Canals that raise yields in the short run can reduce them over time unless drainage, crop choice and efficient irrigation are built in.

Why Is This Topic Important?

Erosion Topsoil loss
Irrigation Salt, wet
Fix Cover, drainage

What Came Next?

The next topic covers soil conservation measures. Next topic: Soil Conservation Measures.

Key People and Terms

Sheet erosion Uniform topsoil removal
Gully Deep erosion channel
Saltation Bouncing sand
Waterlogging Saturated root zone
Alkalinisation Sodium build-up
Reh Saline soil

Exam Corner

Points to Remember

Water erosion: splash, sheet, rill, gully.
Ravines: Chambal.
Irrigation causes waterlogging and salinity.
Gypsum treats alkaline soil.
Drip saves water.

Do Not Confuse With

Sheet and rill erosion Thin layer versus small channels
Saline and alkaline soil Soluble salts versus sodium
Saltation and suspension Bouncing versus floating particles

Memory Hook

Splash, sheet, rill, gully, then ravine; too much water brings salt and swamp.

Mains Angle

Questions ask for types and problems. These points help.

Erosion Types, causes
Irrigation Salt, waterlogging
Fix Cover, drainage

A Question You May Face

An original practice question, not a past paper question.

“Discuss the types and causes of soil erosion in India and the problems arising from excessive irrigation.”

How to Answer

Types Water, wind.
Causes Human.
Irrigation Problems.
Fix Practices.

GS Relevance

Prelims: erosion types, agents, irrigation problems. GS Paper 3: soil conservation and agriculture.

Frequently Asked Questions

What is soil erosion?

Soil erosion is the detachment and removal of soil particles by water, wind, ice or gravity. Natural erosion is slow, but human activities such as deforestation, overgrazing, steep slope farming and construction accelerate it, removing fertile topsoil much faster than new soil can form.

What are the types of water erosion?

Water erosion includes splash erosion by raindrops, sheet erosion that removes a thin layer of topsoil over a wide area, rill erosion that cuts small channels, and gully erosion that cuts deep channels. Severe gully erosion creates ravines and badlands, as seen along the Chambal river.

What is the difference between saline and alkaline soils?

Saline soils contain high amounts of soluble salts such as sodium, calcium and magnesium chlorides and sulphates, often with a white surface crust. Alkaline soils have high exchangeable sodium and high pH, with poor structure that becomes hard when dry. Saline soils are leached, while alkaline soils need gypsum.

How does excessive irrigation cause waterlogging and salinity?

Too much water from canals and flooding, without proper drainage, raises the water table until it saturates the root zone, causing waterlogging. In dry climates, evaporation then pulls water and dissolved salts upward, leaving salts on the surface and making the soil saline or alkaline, which reduces crop growth.

What is wind erosion and where is it common?

Wind erosion is the removal and transport of fine soil particles by wind through saltation, suspension and surface creep. It is common in dry regions with sparse plant cover, such as the Thar in Rajasthan and parts of Gujarat and Haryana, where it moves sand dunes and removes topsoil.

PYQ Practice — Statement Analysis

1 Gully erosion has created the Chambal ravines.

True

Deep channels in alluvium.

2 Sheet erosion is easily visible.

False

It is hard to notice.

3 Over-irrigation can cause soil salinity.