ENVIRONMENTAL SCIENCE : NATURAL RESOURCES 95
water logging. Water and wind erosion alone has affected 150 million hectares of fertile
land. Our entire cultivated area is only 160 million hectares. In this way, it becomes clear
that our degraded land is more than all our arable land put together.
It is evident from the report of NCEPC that India was losing more than 6,000 million
tones of top soil per year in 1972 which in terms of major nutrients-N.P.K. alone represented
an annual loss of Rs. 700 crore. Today the loss is many times more. It is our duty to identify
the areas of maximum concern, and the means to check damage in these areas.
SOME EFFECTS OF SOIL EROSION
Every year in India, water erosion alone takes away more than 6,000 tonnes of top soil,
containing more than Rs. 1000 crores worth of nuitrients. Its evil effects are as under:
- This erosion causes the rapid siltation of tanks and reservoirs.
- Silt is choking our estuaries and harbours.
- Eroded soil is deposited on riverbeds, raising their levels and leading to devastating
floods, which cause Rs. 2,000 crores of damage each year. - The land area prone to floods has doubled from 20 million hectares in 1971 to 40
million ha. In 1980. - Denuded land cannot soak up water like wooded land, so and increasing amount
of rainwater is thus running waste into the sea, causing silting and flooding in the
process.
As a result there is much less water stored in underground aquifers, which are vital to
maintain river flower in the dry season and provide water for tubewell irrigation.
Position in Kerala
Rains have been eroding Kerala coast. During monsoon there occurs extensive damage
due to sea erosion. The worst affected areas are as under:
(1) Poonthura, Panathura and Kotaqpuram in Trivandrum Distt.
(2) Edava, Thanni and Eravipuram in Quilon Distt.
(3) Thikkunnapuzha, Arattupuzha, Punnapra, Thumboli, Anthakara Azhi and Palithodu
in Aleppey Distt.
(4) Kannamali, Puthenthodu, Cheria, Kadavu and Nayarambalam in Ernakulum Distt.
And
(5) Kadapuram, Eriyad, Perinjanam, Kaipamangalam and Engandiyoor in Trichur Distt.DESERTIFICATION: MEANING CONCEPT CAUSES
Meaning of Desertification: Desertification can be defined as a process of degradations
of the environment, that usually is a product of climate and human activity and involves the
spread of extension of desert-like conditions in a hitherto fertile area.
In this way Desertification process is leading to desert formation, It may be either due
to a natural phenomenon linked to climatic change or due to abusive land use. However, the
improper land use practices besides soil erosion greatly lead to climatic change. Removal of