Soil erosion is not the outcome of a single factor but a multiplicity of factors. Amongst the mention may be made of deforestation, over-grazin by cattle (mainly sheep and goat), shifting cultivation practised by tribal’s, unscientific farming techniques, diversion and obstruction of natural drainage courses by transport and communication lines, and unscrupulous mining activities.
In general man plays a dominant role in accelerating the process of soil erosion. In fact modern concept of development based on material comfort has led to over exploitation of environmental resources causing immense damages to eco-system. Soil is an important natural resource and a part of ecosystem.
Soil Erosion in India
In India the problem of soil erosion has attained a menacing proportion. In fact this is the first great enemy of Indian agriculture responsible for low agricultural productivity. According to Sir H. Glover about 80 million hectares of country’s area (another estimate 126.6 million ha.) is suffering from soil erosion. According to another estimate every year rain-water alone washes out 1/8 cm thick fertile top soil. Table 7.Ill shows the statewide distribution of areas affected by soil erosion and degradation. Here Rajasthan with 37.39 million ha. Comes on the top followed by Madhya Pradesh,
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Maharashtra, Uttar Pradesh, Gujarat, Andhra Pradesh and Karnataka. The worst affected areas include:
(i) The badlands of the Chambal and Yamuna rivers,
(ii) the piedmont zone of the western Himalayas, (iii) the Chotanagpur plateau region, (iv) the Tapi- Sabarmati valley region in Gujarat, (v) the Regard soil area of Maharashtra, and (vi) the dry areas of Rajasthan, Gujarat and Haryana.
In Uttar Pradesh the problem of soil erosion is worsening day by day. Vrajabhumi (Mathura and Agra) which was earlier famous for its greenery and milk products is gradually being engulfed by the advancing desert due to excessive grazing and loss of vegetal cover. The windblown desert sand is not only affecting the soil fertility in adjoining states of Haryana, Punjab, Uttar Pradesh, Madhya Pradesh and Gujarat but increasing the quantity of silt deposits in the canals of Punjab and Haryana.
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The ravines of Agra, Mathura and Etawah are the outcome of soil erosion. The sheet erosion active on the wastelands of Avadh, Bundelkhand and Agra region since last 200 years has so far removed 0.3 m thick of fertile soil cover. The Chambal-Yamuna badlands, covering a total area of 32 lakh ha. (Length 110 km), are the result of 1000 years of soil erosion w 0.25 tones of soil is being removed every day. 1 has become the hideout for criminals and the flood plain areas of the Ganga; tributaries are not free from this problem of erosion.
These rivers are gradually carving out furrows and removing fertile top soil. According to one estimate Ganga River is annually transporting 36 million tones of eroded material from the plains to the Bay of Bengal. Bordering areas of all the rivers of Assam and West Bengal suffer from the problem of soil erosion. The indiscriminate cutting of trees along the slopes of the Himalayas has aggravated the problem of soil erosion and landslides.
The regard soil area of Maharashtra is unable to bear the onslaught of soil erosion. Here there has been colossal loss of soil income areas reaching up to 325 tons per hectare per year.
The tribal areas of Assam, Meghalaya, Tripura, Nagaland, Mizoram, Kerala, Andhra Pradesh, Orissa and Madhya where shifting cultivation is carried on, are the menacing problem of deforestation erosion. According to rough estimate about lakh hectares of the country’s area farming where about 15 lakh hectares of land is cleared every year.
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Although wind erosion is only Rajasthan and its adjoining states (area: 45 ha.) the extension of desertification is a great concern. According tones during the last century about 8 million tonnes has been removed from every square kilometer of the desert. Glacial erosion occurs in the periglacial regions of Kashmir, Arunachal Pradesh, Uttaranchal and Himachal Pradesh (area 10,262 sq. km.).