3.2 Land degradation in India
Tropical soils are surprisingly fragile and vulnerable to ruination. Nutrients in tropical soils occur mostly in the plants; the soil offers only the mechanical support for growth. When the canopy protection is demolished, soil temperature is raised to destructive proportions which hasten biological and chemical deterioration of the remaining organic matter. Heavy rains leach away the remaining nutrients and remove these by surface erosion of the productive upper soil horizon causing land degradation. India being in tropical zone gets seriously effected by this process.

Materials disintegrated by weathering and erosion are carried by running water. Some studies (Agarwal & Narain, 1991) revealed that in terms of sediment load carried by rivers, among the top five rivers of the world, three are those which passes through India. As per some scientists of UNEP (Mohanty, 2001) 2/3rd of world's sediment transport to oceans is from southeast Asia.

Sedimentation rates in irrigation cannels and dams of India are now four to five times more than originally calculated by the designers (Valdiya, 1987). The forests at the foot hills at the banks of the rivers Indus and Ganges that were formerly inhibiting heavy run-off are now mostly lost.

More than 40% of land in India is seriously affected by erosion of one kind or other. The Indian rivers together carry to the seas annually about 1500 million ton of eroded material produced at the rate of 4.5 t/ha/yr., compared to the global amount of 24000 million ton removed from the vulnerable parts of the earth at the rate of 3'6 cm/1000 years. Erosion has become critical and pronounced in areas where man has indiscriminately used the land and tampered with natural balance by reshaping, modifying and defacing the topography, chiefs of some such activities being mining and deforestation due to related activities particularly on hillsides where the geodynamic conditions don't accept such disturbance.

It had been reported (Coates, 1981, pp.506) that 75% of Indias forest was lost in past 20 years, some parts of Nepal was having not even sufficient timber to cremate the dead bodies. Large tracts of Nepal had only 3 cm of topsoil.

As a result of such accelerated erosion the country is loosing valuable land at a rate of 5 to 7 million ha per yr. (Valdiya, 1987, pp.175). Reservoirs created for the purpose of electricity generation and irrigation are being filled so rapidly that their lives have been reduced by 1/4 th or 1/5th of the original. The deposition of sediments in the river beds has reduced their carrying capacity leading to overflow and recurring floods, that now spread over vaste and vaster areas.

The process of land degradation is intricately connected with desertification. About 5.7% of Indian landmass is a desert or desertic and quite a large part (one-third of the geographic area encompassing 76 districts) is cronically drought prone of which 13% area is on the brink of total desertification (Valdiya, op.cit.).

Inspite of the fact that the National Forest Policy of India states the requirement of 33% land under forest or green cover, India's average forest cover amounts to about 20% (considering the different sources of information). This indicates that India is far behind the target There are some mining areas in India (MAs) (e.g. Jharia coalfield) with even less than 3% land under forest cover (Ghosh, et al., 1997). Further some studies on coal mining areas of India (CMAs) have revealed that rate of dwindling of forest cover is significant (Ghosh & Rani 1999). These reveal the fact that decrease in forest cover is a characteristic feature of MAs.

Some UNEP information (Mohanty, 2001) states that the Asia Pacific is suffering deforestation @1.6% /year. The problem is getting aggravated inspite of a country-wide green revolution since 1980s, with a special attempt to generate green cover in MAs. This indicates the existence of some unidentified factor(s) opposing all the efforts to green the mining degraded lands. These factor(s) must be much powerful than the efforts being put by the country, including the mining companies, forest departments and all others working to increase the forest cover. It appears that the prime requirement is to identify the basic cause(s) of persistency of the problem (decreasing green cover in the mining areas) inspite of the countrywide effort, and then to up-root the cause (working as lacuna). This calls for an efficient LUPg system to manage the observed problem, i.e. for preparing a LUMP for at least the MAs.