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Today’s lesson:. To understand the causes, effects and possible solutions to soil erosion, soil pollution and desertification in China. Soil erosion, desertification and forestry in China. Exam question:
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Today’s lesson: To understand the causes, effects and possible solutions to soil erosion, soil pollution and desertification in China.
Soil erosion, desertification and forestry in China • Exam question: • “Pollution is now so serious that policies on pollution control must inevitably change.” To what extent do you agree with this statement with respect to present – day China? Illustrate your answer with specific examples.
Our soil is a layer of life (at times a very thin & fragile layer). What is soil? • Soil is a mixture of broken rocks and minerals, living organisms, and decaying organic matter called humus. Humus is dark, soft and rich in nutrients. Soil also includes air and water. • So, soil is vital.
What is soil erosion? • What causes soil erosion?
Overgrazing is the major cause of desertification worldwide. Vegetation is lost both in the grazing itself and in being trampled by large numbers of livestock. Overgrazed lands then become more vulnerable to erosion as compaction of the soils reduces infiltration, leading to greater runoff, while trampling increases wind erosion. Fencing, which confines animals to specific locations and the provision of water points and wells has led to severe localized overgrazing. Boreholes and wells also lower the water table, causing soil salinisation. • Deforestation is most obvious where land has been cleared to extend the area under cultivation and in the surrounds of urban areas where trees are stripped for firewood. The loss of vegetation cover increases rain splash erosion and the absence of root systems allows easy removal of the soil by wind and water. • Overcultivation leads to diminishing returns, where the yield decreases season by season, requiring an expansion of the areas to be cultivated simply to maintain the same return on the agricultural investment. Reducing fallow periods and introducing irrigation are also used to maintain output, but all these contribute to further soil degradation and erosion by lowering soil fertility and promoting salinisation.
Other factors are involved, and they include: • The mobility of tribes people has been limited by governments, especially where their migratory routes crossed international boundaries. Attempts to provide permanent settlements have led to the concentration of population and animals, with undesirable consequences • weak or non-existent laws have not provided environmental protection for marginal land by preventing or controlling its use • irrational use of water resources causing water shortages or salinisation of soil • civil strife and war diverts resources away from environmental issues • international trade has promoted short-term exploitation of land by encouraging cash crops for export. This has disrupted local markets and created a shortage of staple food • ignorance of the consequences of some human actions and the use of inappropriate techniques and equipment have contributed to the problem.
The consequences of desertification and soil erosion... • Environmental • loss of soil nutrients through wind and water erosion • changes in composition of vegetation and loss of bio-diversity as vegetation is removed • reduction in land available for cropping and pasture • increased sedimentation of streams because of soil erosion, sediment accumulations in reservoirs • expansion of area under sand dunes • Economic • reduced income from traditional economy (cultivation of food crops) • decreased availability of fuel/wood, necessitating purchase of oil/kerosene, which contributes to air pollution • increased dependence on food aid • increased rural poverty • Social and cultural • loss of traditional knowledge and skills • forced migration due to food scarcity • social tensions
One fifth of China's farmland polluted Pollution Rising, Chinese Fear for Soil and Food China admits widespread soil pollution in ‘state secret’ report
From here -Essay feedback Soil pollution
Let’s mind map this. How far can we take this? What are the issues? What are the causes? What needs to happen? What is your opinion? What do you think? Write this down.
Desertification and Land Degradation in China - article • This is a 13 page paper which goes into a lot of detail about this topic. • Use this to enhance your notes with data. • It includes details on forestry in China as well – this is in the exam syllabus.
Forestry in China • Use the report to add some key points here, but we will go through the basics together. What are forests used for? Classes of forest – protective, special purpose, public benefit forest, timber, fuel, economic – fruit, chemicals medicinal, flavour seasoning.
Forestry goals in China • New developments with China’s forest resources • Remaining challenges.
Soil erosion and desertification in China • Exam question: • “Pollution is now so serious that policies on pollution control must inevitably change.” To what extent do you agree with this statement with respect to present – day China? Illustrate your answer with specific examples.
Pollution is now so serious that policies on pollution control must inevitably change.” To what extent do you agree with this statement with respect to present – day China? Illustrate your answer with specific examples. • What do we talk about here? • Candidates need to demonstrate knowledge of environmental pollution with respect to: • Water • Air • Waste disposal • Soil and forest erosion. You need to: Demonstrate your specific knowledge of these areas of pollution and how China are attempting to mitigate the environmental impact of them. You can express your opinion/ thoughts here as long as you can illustrate this with examples.
You could say... • that the status quo is fine – things will get better over time, • that there needs to be stricter implementation of existing policy, or • that new and more stringent policies need to be enforced – environment and health impacts need to be put before economic growth.
Next time... • population • I may try and book a computer room /use ipads for you to do some reserach!!
