Core 3 - patterns in environmental quality and sustainability

Pregunta	Respuesta
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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Core 3 - patterns in environmental quality and sustainability

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