Q.5 Discuss the environmental effects of extracting and using mineral resources. (AKTU. - 2004-05, 05-06, 07-08, 08-09)
Ans. The environmental effects of extracting and using mineral resources depend on such factors as ore quality, mining procedures, local hydrological conditions, climate, rock types, size of operation, topography and several other related factors.
Social impacts result from the increased demand for housing and other services in mining areas. Some of the effects are -
1. Pollution: -
Mining operations often pollute the atmosphere, surface waters and ground water. Rainwater seeping through spoil heaps may become heavily contaminated, acidic or turbid with potentially devastating effects on nearby streams and rivers.
2. Destruction of land:-
Mining activity can cause a considerable loss of land because of chemical contamination, destruction of productive layers of soil, and often permanent scarring of the land surface. Large mining operations disturb the land by directly removing material in some areas and by dumping waste in others. There can be a considerable loss of wildlife habitat.
3. Subsidence: -
The presence of old, deep mines may cause the ground surface to subside in a vertical or horizontal direction. This may severely damage buildings, roads and farmland, as well as alter the surface drainage patterns.
4. Noise: -
Blasting and transport cause noise disturbance to local residents and to wild life.
5. Energy: -
Extraction and transportation requires huge amounts of energy which adds to impacts such as acid rain and global warming.
6. Impact on the Biological Environment: -
Physical changes in the land, soil, water and air associated with mining directly and indirectly affect the biological environment. Direct impacts include death of plants or animals caused by mining activity or contact with toxic soil or water from mines.
Indirect impacts include changes in nutrient cycling, total biomass, species diversity, and ecosystem stability due to alternations in groundwater or surface water availability or quality.
7. Long-term supplies of mineral resources: -
The economies of industrialized countries require the extraction and processing of large amounts of minerals to make products. As other economies industrialize, their mineral demands increase rapidly.
Q.6 Describe the necessity of conserving mineral resources. (AKTU. - 2007-08)
Ans. Necessity of Conserving Mineral Resources: -
Some mineral elements are essential for the formation and functioning of the body of all organisms, plants as well as animals, including human beings. But the humans today use a wide variety of minerals, many in large quantities to sustain his industry based civilization. Modern society depends on the availability of mineral resources, which can be considered a non-renewable heritage from the geologic past. Although new deposits are still forming from earth processes, but these processes are producing new mineral deposits too slowly to be of use to us today. Unlike forestry or agriculture (biological resources), where crops can be grown over and over again, mining is a robber industry. However large the deposit of a given mineral is, continuous mining will exhaust the ores. Hence minerals are thus a finite and declining resource.
Therefore, it is necessary to conserve the mineral resources.
Q.7 What is deforestation? Enumerate and discuss the various causes of deforestation. (AKTU. - 2008 - 09, 10-11, 12 - 13)
Related Questions -
Q. What is deforestation? Enumerate and discuss the various causes of deforestation. What remedial measures do you suggest? (AKTU. - 2011 - 12)
Ans. Deforestation: - (AKTU. - 2009 - 10)
Deforestation is defined as the permanent destruction of indigenous forests and woodlands. In other words deforestation is the reckless felling of trees by human being for their ulterior ends. Deforestation has resulted in the reduction of indigenous forest to four-fifth of their preagricultural area.
Forests are burned or cut-down for various reasons, like clearing of land for agriculture, harvesting of timber, expansion of cities and many more; but the aim behind all these reasons is “economic gains”. At present we are losing forests at the rate of 1.7 crores hectares annually world-wide.
Causes of deforestation: -
The main causes of deforestation are as follows -
- Deforestation occurs due to overgrazing and conversion of forest to pasture for domestic animals.
- Floods, storms, snow, lightening etc. are the natural forces which damage forests.
- Fuelwood gathering is also an important deforestation agent in dry forest.
- Deforestation also occurs due to mining, quarrying and irrigation and industrial projects.
- Forest fire are also cause of deforestation. Fires in the forest may be due to natural calamities or human activities.
- Shifting cultivation (also called ‘Jhum Cultivation’), that is slash and burn agriculture, practices by land less indigenous people or tribals who clear trees to grow subsistence crops is the principal cause of deforestation in the tropics.
- Expansion of agribusiness that grows oil palm, rubber, fruit trees and ornamental plants has also resulted in deforestation.
- Commercial logging is another deforestation agent.
- Gonvernment sponsored programmes that resettle landless farmers on forested sites have contributed to deforestation all around the world.
(a) Timber and fuel wood should be used very economically by minimising wastage.
(b) Alternate sources of energy such as biogas, solar energy etc. should be developed to supplement fuelwood.
(c) Overgrazing and deforestation should be prohibited. Reforestation of deforested areas should be encouraged.
(d) Pest and fire control by modern techniques should be adopted to prevent loss of forests.
(e) Forestry should be improved by modern techniques like use of fertilisers, irrigation, weed control, tissue-culture etc.
Another vital aspect of forest conservation is afforestation which means growing of forest in areas unfit for agriculture due to adverse climatic and edaphic factors like saline waterlogged unstable soils etc.
