733310
Description
Flashcards by linda_rousseva, updated more than 1 year ago
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Created by linda_rousseva
about 10 years ago
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| Question | Answer |
| soil degradation | the physical loss (erosion) & reduction in quality of topsoil associated with nutrient decline & contamination |
| soil profile | the vertical variations that occur in the characteristics of a soil from the surface to the underlying rock |
| biological soil degradation | the loss of humus and plant/animal life |
| physical/mechanical soil degradation | loss of structure & changes in permeability |
| chemical soil degradation | acidification, declining fertility, changes in pH, salinization and chemical toxicity |
| soil leeching | movement of water through the soil ‘leeches’ the top soil nutrients downwards (out of plants’ reach), reducing the fertility of the soil |
| physical water scarcity | when water is physically absent in an area due to climatic/geological reasons, and doesn't meet the requirements of the population |
| human water scarcity | when the water available in an area does not meet the requirements of the population because it is not clean & safe |
| economic water scarcity | when the water available in an area is potentially unaccessible by the population because of lack of investment to make it potable, or poor infrastructure to distribute it |
| deforestation | the process of destroying a forest and replacing it with something else, e.g. agricultural system |
| overgrazing | the grazing of natural pastures at stocking intensities above the livestock carrying capacity |
| acidification | the change in the chemical composition of soil, which may trigger the circulation of toxic metals |
| salinization | the condition in which the salt content of soil accumulates over time to above normal levels; can occur where water containing high salt concentration evaporates from fields irrigated with standing water |
| soil aggregates | soil particles that are closely found together are called peds or aggregates |
| desertification | the gradual transformation of habitable land into desert |
| dust storms | severe windstorms that sweep clouds of dust across extensive areas, especially in an arid region |
| soil buffering capacity | the capacity of soil to absorb contaminants |
| carbon farming | using plants grown on a farm to 'harvest' carbon from the atmosphere and return it to the soil |
| perennial crops | crops that do not die off once harvested, existing from years before reseeding may be required |
| afforestation | planting seeds/trees to make a forest on land that has not been a forest recently or has never been a forest |
| reforestation | re-establishing a forest after its removal |
| sustainable agriculture | agricultural systems emphasizing biological relationships and natural processes, which maintain soil fertility thus allowing current levels of farm production to continue indefinitely |
| sustainability | using resources without jeopardizing future capacity to use those resources |
| human causes of soil degradation | agriculture mismanagement (overgrazing, over-cultivation, monoculture, fertiliser & pesticide use, HYV & GM crops, unsustainable water use) ,deforestation, overpopulation, industrial pollution, toyotarization (increased use of 4x4s damaging top soil), conflict |
| physical causes of soil degradation | rising temperatures, falling rainfall, flash floods, wind, topography(if land is flat then it is less vulnerable to water erosion but more to wind erosion & vice versa) |
| impacts of soil degradation on the environment | land becomes less stable, loss of fertility, desertification, loss of ecosystems & biodiversity, water supply decreases, water & carbon cycles disrupted, climate change |
| solutions to soil degradation | change crop production, livestock management, forestry management, water & land management, socio-economic factors |
| how is changing crop production a solution to soil degradation? | diversifying crops, organic fertilizers, increase resistance to drought, improve irrigation systems |
| how is livestock management a solution to soil degradation? | improve quality of animals (disease control, selective breeding), reduce livestock populations to not exceed carrying capacity, improve rangelands by allowing regeneration |
| how is forestry management a solution to soil degradation? | protect existing trees, manage fuelwood forests, reduce wood consumption, introduce other energy sources e.g. solar and wind power |
| how is water & land management a solution to soil degradation? | improve irrigation, increase water harvesting by e.g. setting up lines of stones, increase incidence of windbreaks |
| how are socio-economic factors a solution to soil degradation? | guarantee tenure/land ownership, educate people to increase local awareness of desertification and to inform people of the skills to combat it, provide buffer stocks of food & resources to reduce people involved in schemes that may short-term reduce the output of the land, improve health services |
| case study examples for soil degradation | planting acacia trees in West Africa (Sahel region) e.g. Kenya, Somalia and India (stabilized 600km2 of sand dunes since 1980); building walls of stones to prevent soil being washed away in Burkina Faso (increase crop yield by 50% since 1990); building the 'Great Green Wall' in China to hold off the advancing Ghobi desert (protects 80000km2 of valuable crop land, and increased crop yield by 13% in 1990) |
| physical causes of water scarcity | arid regions (high atmospheric pressure), rain shadows (air rises and cools when reaches a mountain and rains on one side, leaving the other side dry), climate change & variability (droughts, severe flooding) |
| human causes of water scarcity | population growth, land use (e.g. deforestation for food production/resource use), pollution of water (e.g. contamination due to industry/agriculture/sewage) |
| methods to deal with human water scarcity | LIFESAVER® system, managing wastewater & pollution control (not dumping in areas where it cannot be reused, using for agriculture, primary & secondary treatment removing 85% of suspended solids and some of organic matter/life), desalinization of sea water, case study: Bangladesh (community education & training in proper education and soil management, helping small-scale farmers, piping water to domestic households using the community for manual labor, etc.) |
| methods to deal with physical water scarcity | water conservation, transferring water from water-rich to water-scarce basins, case study: Las Vegas & the Great Basin Aquifer |
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