District Survey Reports
About Punjab
Major Environmental Issues in Punjab
Agriculture
Air
Biodiversity
Climate Change
Database on Maps
Demography
Disaster
Energy
Environmental Conventions and Conferences
Environmental Standards
Forest Resource
Graph Gallery
Industries
Land
Policy and Legislations
Searchable Database
Solid Waste
Static database
Water
Water Supply and Sanitation
  • Soil erosion is the physical removal of the top soil layer or soil particles by mobile agents and by human activities.  Running water, rainfall and wind are the primary mobile agents, which cause soil erosion in the absence of vegetative cover, and moisture and it is further helped by gravity and ruggedness of topography. 
  • Soil erosion is influenced by its physical, chemical, hydrological, and mineralogical properties and its soil profile characteristics.
  •  Physical and hydrological properties of soil affect the resistance of soil to erosion, which includes texture, structure, water holding capacity and transmission properties of any soil.
  • Important soil erosion components of the hydrological cycle are: Infiltration, surface detention, velocity of overland flow, and flow of subsurface water.
  • The various types of flow and their velocities may be turbulent or laminar, steady or unsteady, uniform or non-uniform and influence the extent of erosion
  • Water balance, evapo-transpiration, temperature and relative humidity have an indirect effect on soil erosion. Indirect factors affect rainfall by altering the proportion of rainfall and soil moisture regime.
  •  Important soil erosion components of land form are: Slope gradient, slope length and shape of slope which affect erosion processes of splash erosion, sheet erosion, rill erosion, and gully erosion.
  • The equilibrium between denudation and soil formation is easily disturbed by the use and abuse of natural resources. Human beings play an important role in causing soil erosion through unsustainable management of  natural resources like:

o        Deforestation

o        Destruction of the natural vegetation by overgrazing

o        Defective cultivation systems like continuous cultivation of same crop

o        High crop intensity

o        Construction and mining activities

TYPES OF SOIL EROSION

Based on the rate at which soil loss take place, there are two major types of soil erosion:  

  • Geological soil erosion: Occurs under natural and normal conditions without any interference of man. It is very slow process and equilibrium between loss and build up is hardly lost, unless there are some major disturbances by a foreign agent.
  • Accelerated soil erosion: This type of removal of soil is very rapid and never keeps pace with the soil formation. This is the most serious type of loss, generally caused by the interference of an agency like man and animals.

There are various type of soil erosion based on various agents that bring about soil erosion and the form in which the soil is lost during erosion.

  • Water erosion: Water erosion is caused by the kinetic energy of rain falling on the soil surface and by the mechanical force of runoff. Depending up on the form of the lost, it may be:

    • Sheet erosion: Removal of soil like a thin covering from large area.
      • Rill Erosion: If sheet erosion occurs with full force, the run off water moves rapidly over the soil surface caused rill erosion.
      • Gully erosion: This results due to convergence of several rills (Thin channels formed during rill erosion) towards the steep slope, which forms together wider channels of water known as gullies.
  • Wind erosion: Wind erosion is the removal of soil particles by the force and kinetic energy of the wind. These soil particles are transported and deposited when the wind energy drops. Depending up on the mechanism of soil removal this may be of the following types:

o    Saltation: It occurs in arid regions where rainfall and drainage is poor and high temperature prevails, water evaporates quickly leaving behind the salts in soil.The major portion of such salty soil carried by wind.

o      Suspension: The wind throws away smallest soil particles into air which moves as fine dust in the wind.

o     Surface creep: The largest particles of soil that are not easily thrown up by wind are simply pushed or spread along the surface by wind.

·  Stream Bank Erosion: Inadequate maintenance of surface drainage systems, uncontrolled livestock access, and cropping too close to both stream banks has led to bank erosion problems. This type of erosion is also known as riparian erosion.

·        Gravity Erosion: Mass movement of soil particles occurs on steep slopes under the influence of gravity. The process involves the transfer of slope-forming materials from higher to lower grounds due to self weight.

Status of Soil Erosion:

  • In India Water Erosion is the major problem causing loss of top soil and/or terrain deformation in about 148 million ha representing 45% of the total geographical area of the country (Source: www. nbsslup.nic.in).
  • The Punjab is also facing very serious problem of soil erosion by water. It is serious menace in the Shivaliks and Kandi region, along the river courses, streams and choes and in the south western arid and hot region.
  • It is more prevalent in Gurdaspur, Nawashehar, Hoshiarpur and Ropar districts of north-eastern of Punjab where water erosion by various choes and streams is much more and is aggravated by the loose structure and softness of rocks, steep slopes, deforestation overgrazing and various cultural and economic activities of man.
  • Here it is done through rain splash, sheet erosion, rill, gully and stream erosion. (Source: Geography of Punjab, Manku. D.S, 2002). 
  • In sub-mountain region of Punjab, runoff is one of the major modes of escape of rainwater received in the area. Various factors of soil erosion (erodibility of the soil, slope of the land and nature of the plant cover) were studied by Kukal et al., 2007 in the said region.
  • Studies in the area have indicated that runoff during the monsoon period varies between 24 and 36 percent, whereas annual loss of rainwater varies between 26 and 42 per cent.
  • As far as individual storms are concerned, the runoff varies from none to as high as 80 per cent. The peak runoff rates recorded in the area are sufficient to cause flash floods.
  • The runoff carries along with it upper fertile soil rich in applied nutrients, thereby decreasing productivity of the soil. The whole Kandi region have been rendered infertile and dissected and are prone to flooding by hundreds of choes that  transverse the districts of Hoshiarpur, Gurdaspur, Nawashehar and Ropar from Shiavilks to the flat alluvial plains.
  • It covers nearly 11% area of the state. As per Central Water Commission (2003), 9140 sq km area in the state is prone to water erosion.
  • As per results of a study conducted by PAU’s Zonal Research Station, large and small catchments of non arable lands (pastures/ current fallow/cultivable waste land) in Shiwalik foothills have been more affected by water erosion as compared to arable land.

 

Runoff and soil loss from non-arable and arable land of varying size in the Shiwalik foothills of Punjab  (Click Here)

  • In rest of the state water erosion is confined to “Dhahas” (ravines) along the rivers, especially along river Beas. This area is less than one lakh hectare (Source: Department of Soil and Water Conservation, Punjab, 2002).
  • Various choes are being integrated into major choes and check cum irrigation small dams have been or are being constructed across various choes to check soil erosion and flooding and providing irrigation at local level.
  • Wind erosion is dominant in the western region of India, covering 13.5 million ha (Source: National Beuro of Soil Survey and Land use Planning as cited on www.nbsslup.nic.in). It causes loss of top soil in 1.9 per cent, terrain deformation in 1.2 per cent and over blowing and shifting of sand dunes in 0.5 per cent of the affected area.
  • Wind erosion is a problem in south-western districts of Punjab like Firozpur, Bathinda, Mansa, Faridkot and mansa in the state. Wind speeds exceeds 20 km/h are common during dry months in Punjab.
  • Wind erosion has led to the formation of sand dune, sand bars and sand flats in these districts As per 2003 data provided by Central Water Commission, 10,900 sq km area is prone to wind erosion in Punjab. 
  • In the central and lower south-western part of the area, high soil credibility and sparse vegetation were the most important factors (Kukal et al., 2007).
  • The progressive, hard working and enterprising farmers of Malwa plain of Punjab have checked the onslaught of sand dunes and wind erosion in co-operation with various Govt. agencies.
  • As per soil surveys and aerial photographs conducted by Punjab Agriculture University, Ludhiana and  Department of Soil  Conservation  and Engineering Punjab, the area of sand dunes in the various parts of the state has been decreased. This change in Kapurthala district was from 22.7% to 2.3% of the total land of the district.

Effects of Soil Erosion

  • Soil erosion by various factors causes wide range of problem in land management and water bodies.
  • As a result of erosion over the past 40 years, 30 percent of the world's arable land has become unproductive (Lang, Susan S.,March 20, 2006).
  • About 60 percent of soil that is washed away ends up in rivers, streams and lakes, making waterways more prone to flooding and to contamination from soil's fertilizers and pesticides.
  • Soil erosion also reduces the ability of soil to store water and support plant growth, thereby reducing its ability to support biodiversity.
  • Erosion promotes critical losses of water, nutrients, soil organic matter and soil biota, harming forests, rangeland and natural ecosystems.
  • Erosion increases the amount of dust carried by wind, which not only acts as an abrasive and air pollutant but also carries about 20 human infectious disease organisms, including anthrax and tuberculosis (Lang, Susan S.,March 20, 2006).
  • The most important effect of soil erosion is the loss of top soil thus converting otherwise productive soils into shallow soils which is one of the major factors of low and unstable crop yields in the rain-fed semi-arid to sub-humid tropics of India.
  • There are vast areas of degraded common grazing lands, uncultivable waste lands and degraded forests that pose a serious threat to adjoining productive crop land.
  • The off-site effects of water erosion include siltation of reservoirs. There are evidences to show that the capacity of several reservoirs has decreased at a much faster rate than envisaged at the planning stage. This adversely affects the capacity to sustain the gains in productivity over the past decades.
  • The frequency of floods and droughts, considered as natural disasters, is increasing and their management becoming more difficult.
  • Chemicals in the form of fertilizers, weedicides, insecticides etc. used in agricultural fields get lost in running water and ultimately find their destination in various water bodies, thus posing a threat to the existing flora and fauna native to these aquatic bodies.

Mitigation measures

  • The problem of soil erosion is started aggravating in the certain part of the state, the government and farmers of the state are started taking various measures to check soil erosion in various parts of the state.
  • Among the various measures  are included afforestation, check on overgrazing, better management, rotation of crops, extension of irrigation, adoption of dry farming methods, construction of wind brakes belts, improved methods of cultivation, construction of check dams, etc.
  • Other ways to reduce erosion include reducing the need for people in developing countries to clear forests for agriculture and remove crop residues for cooking fuel.

                                                                               Source: Department of Soil & Water Conservation, Punjab