Observation on effect of deforestation
Some data on effects of deforestation (Coates, 1981) has been detailed in section 2.3. the extent of land degradation in India has been detailed in section 3.2. Further, that rainfall erosion on OC mined lands bears an importance in ecological perspective is clear from other scientists also (Nicolau & Asensio, 2000).

That effects of erosion are more prominent in catastrophic storms in hilly terrains is proved by the set of data (Ives & Messerli 1989) which states that the rate of erosion in

* Ganga/Brahmaputra watershed is 0.70mm per yr. (after influx to Bay of Bengal fan)
* Darjeeling area is 10-20 mm per yr. (in catastrophic storms)

The seriousness of erosion rate in India is clear from the fact that if the annual sediment transport of top five rivers of the world are compared, the three rivers in the list are those which pass through India. This is revealed from table 3.1.

Table 3.1: Sediment load of top five rivers of the world (c.f. Holeman, 1968)

River name	Location	Sediment load (million t/yr)
1. Yellow	China	2080
2. Ganga	India & Bangladesh	1600
3. Brahmaputra	China, India & Bangladesh	800
4. Yangtze	China	550
5. Indus	India & Pakistan	480

A later data (Narayan & Babu, 1983) however reveals slight decrease in sediment load of rivers passing through India, i.e. Ganga 586 million t/year, Brahmaputra 470 million t/yr., and Indus 106 million t/yr.

It has further been estimated (Agarwal & Narain 1991) that out of the total annual soil loss from India which is about 5334 million tons, approximately 61% gets deposited in rivers, about 10% gets deposited in dams and 29% is lost to sea. It is a serious loss and definitely helps land degradation in India. Further it is a point to realise that a part of this problem (though may not be major) is contributed by the mining and related activities, mainly deforestation, loosening and baring the land surface. The demand of the situation is that already the amount of damage caused is colossal, a single drop should not be added to this ocean of damage.

3.4 Case studies
3.4.1 cases of contour strip mining
Probably the most important and first official record of impact of OC mining on land that was refused to be accepted by the population around was the problem of contour strip-mining at Dehradoon. The practice of such mining is that soil together with OB and associated rock or lowgrade ore is scrapped off and pushed downslope. Sliding of great volume of debris damages habitations, vegetations, waterbodies, springs etc and whatever exists at the base of the sloping surface.

Such mining in the Mussoori hills over Doon valley have resulted ugly scarification on slope, drastic reshaping of the landscape and serious destruction of forests in the region. It was mining of limestone and dolomite in Dehradoon over a stretch of 40 km from Banog-Cloud End in the north-west to Rani-Pokhri and Sera in the south-east. The problem was aggravated by the principle being followed. The mine owners were picking up only the very high-grade material and discarding the rest. Thus more than 30% of the valuable ores were being discarded and thrown off to slide down the 30o-50o slope. In rainy seasons, such rejected loose materials were getting saturated with rain water and forming debris flows descending into the valleys, clogging the channels there, namely Nun, Kiarkuli, Rispara, Baldi and Song, and spreading over fields. According to the estimation of the U.P. Directorate of Geology and Mining, about 1.7 million ton of fine debris thus discarded could have been used for manufacture of cement (Valdiya, 1987 pp. 151). Damage to land and land-use was so serious that the people around filed a case to the Hon'ble Supreme Court against the activity; and the Hon'ble Supreme Court found the situation fit to stop the mining. Reclamation of mined area on slopes more than 14o is rarely successful (Coates 1981), while in Mussoorie mining was being conducted on slopes of 30o-50o . This indiscriminate mining induced serious landslides and aggravated erosion. The debris produced in the construction of roads required for mining was from about 250 km for Mussoorie mines (Negi 1982).

About 14 ha of forested hill slopes above the village Khirakot in the Kosi valley of Almora district and several hundred hectares of the Hiunpani forest in the Chandak area and elsewhere in Pithoragarh district in Kumaun were being haphazardly and crudely mined for soapstone and magnesite respectively. (Valdiya, op.cit.). More than 4820 ha of land area in Kumaun Himalaya, 1147 ha in the Darjiling Hills, 438 ha in Himachal Pradesh and 886 ha in Jammu-Kashmir (Negi, op.cit.) had been ravaged or very seriously affected by mining. In Sikkim, mining of foliated and jointed phyllites for uraniferous polymetallic sulphides created landslides and aggravated erosion.

3.4.2 Cases of area strip mining
The best example of minimum depth of excavation, yet causing serious damage to land is associated with manufacture of bricks. Brick-kilns are very common in eastern India, in the Indo-gangetic alluvial plain. The industry is completely dependent upon a very fine variety of clay which forms a part of topsoil. The industry involves scraping out a layer of topsoil, mixing that with suitable percentage of water, putting that into moulds, then drying and backing these. The topsoil of huge amount is thus consumed by this industry. This top soil is a very precious natural resource, a very important part of lithosphere that takes a major role in proper functioning of the ecosystem. It takes several years to form a cm of topsoil by natural process. Loss of such a rare and important component topsoil damages greenery growing and greenery supporting potentiality of the region and gradually forces it to be turned to a degraded land.

Indiscriminate mining since 1961 had destroyed 50,000 ha of forest in Goa (J. D. Souza, 1984). Against the export of 12 million t/yr of high-grade iron ores 30 million ton of iron ore rejects were being scattered indiscriminately over 10,000 ha of paddy and coconut groves, thus diminishing the fertility of the soil and land. Washing of the mineral ores for beneficiation had caused serious water pollution in the rivers as well as in wells and springs. Use of such polluted water is a cause of land damage.

A study conducted in Kentucky (USA) revealed that the rate of erosion in a strip-mined area was 27,000 t/km2 as compared to only 27t/km2 in the undisturbed hill slope (Tank, 1973).

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