Soil Erosion

Soil erosion is the physical removal of the top soil layer or soil particles by mobil 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 in nature is a beneficial process without which the world would have perished long ago. The same process, accelerated by human mismanagement, has become one of the most vicious and destructive forces ever released by man.“What is usually known as geological erosion or denudation is a universal phenomenon which through thousands of years has carved the earth into its present shape. Denudation is an early and important process in soil formation, whereby the original rock material is continuously broken down and sorted out by wind and water until it becomes suitable for colonisation by plants.The equilibrium between denudation and soil formation is easily disturbed by the activities of man. Cultivation, deforestation or the destruction of the natural vegetation by grazing or other means may accelerate denudation to such an extent that soil, which would normally be washed or blown away in a century, disappears within one year or even within a day. But no human ingenuity can accelerate the soil renewing process from lifeless rock to the acceleration of denudation. This man-accelerated denudation is what is now known as soil erosion.  

In India water erosion is the major problem causing loss of top soil in about 148 million ha (98 per cent of total degraded land). 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) 

In sub mountain Punjab runoff is one of the major modes of escape of rainwater received in the area. Studies in the area have indicated that runoff during the monsoon period varies between 24 and 36 per cent, 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. Recently various measures on government , community and individual level have been taken up to mitigate this problem. 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.

 In India, wind erosion is dominant in the western region, covering 13.5 million ha. 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 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 Wind erosion prevails nearly in 11.5% area of the state. 

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.  

Soil erosion by various factors causes wide range of problem in land management and water bodies.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 fertilisers, 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

 As 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.