Option F Chapter 2 Flashcards
define the term “water footprint”
The water footprint is a measure of the amount of water consumed by a farming activity, an industrial process, a river basin or a country, and it can also be calculated on a global scale
explain how farming inputs and outputs differ between an intensive subsistence and an intensive commercial system
Intensive farming systems have a high
labour or capital input per hectare. Primitive agricultural systems will be labour-intensive, such as subsistence rice growing, whereas commercial systems such as tulip production in the Netherlands have a high capital input. This results from use of greenhouses and other energy subsidies such as fertilizers.
compare the energy efficiency ratio of agro-forestry with that of greenhouse lettuces
The energy efficiency ratio (EER) is the amount of the energy input into a farming system relative to the energy output. Farming systems such as agro- forestry in the tropics use energy from the sun and natural fertilizers. They are energy efficient (EER 65). Conversely, greenhouse lettuce production
in temperate areas requires large energy inputs (subsidies) for greenhouse lighting, heating, transport of other inputs such as fertilizers and transport of lettuces to market. (EER 0.002)
explain the process of diffusion with respect to agricultural innovations
The diffusion of innovations was a process devised by Hägerstrand. In agriculture farmers’ adoption of innovations (new technology, seeds, breeds and techniques) depended upon several factors: information, financial status, personal traits such age and level of conservatism and proximity to other adopters.
Those elderly and conservative farmers living in isolation with inadequate information were slow to adopt and reluctant to change.
describe how diet changes as standards of living increase
As society moves from a state of food shortage to adequate supply and income per household increases, diet usually changes.
Several stages in this process can be observed:
(i) a mineral-deficient, high in carbohydrates and low in protein diet
(ii) the quantity of food increases and nutritional status improves
(iii) with more income society begins to shift towards a diet high in protein and low in carbohydrate. This is called the nutrition transition.
explain how diseases may be spread
There are several types of disease diffusion:
* Expansion diffusion occurs when the expanding disease has a source and diffuses outwards into new areas.
* Relocation diffusion occurs when the spreading disease moves into new areas, leaving behind its origin or source of the disease. An example could be a person nfected with AIDS moving to a new location.
* Contagious diffusion is the spread of an infectious disease through the direct contact of individuals with those infected.
* Hierarchical diffusion occurs when a phenomenon spreads through an ordered sequence of classes or places, for example, from cities to large urban areas to small urban areas.
* Network diffusion occurs when a disease spreads via transportation and social networks. Again, the spread of AIDS in Southern Africa along transport routes is a creditable example.
In addition to the nature and pattern of spread there are several agents involved in this diffusion process:
* Water borne, such as cholera
* Vector-borne, such as malaria, with which the anopheles mosquito carrying the plasmodium parasite is involved.
describe the main impacts of malaria
The impacts may be social and economic and can be viewed at different scales:
(i) Global scale
* In 2015, 95 countries and territories had ongoing malaria transmission.
* About 3.2 billion people – almost half the world’s population – are at risk of malaria.
* Sub-Saharan Africa carries a disproportionately high share of the global malaria burden. In 2015 the region suffered 88 per cent of malaria cases and 90 per cent of malaria deaths.
(ii) National scale
* Malaria can reduce national GDP by 5–6% per annum due to employee absenteeism and the costs of treatment.
* Malaria deters investors and tourists, reducing national income.
(ii) Household scale
* African families lose 25% of their annual income through this disease.
* Education is impacted, wages are lost through absenteeism, and income is severely reduced by the cost of treatment.
suggest ways in which it is possible to manage malaria
Bed nets (ITNs) sprayed with insecticide.
* Indoor spraying with insecticide.
* Vaccination – this attacks the life-cycle of the plasmodium parasite, but it is not yet commercially viable.
give one example of each of the following disease types:
- contagious
- infectious
- degenerative
- non-communicative
(a) Contagious – leprosy
(b) Infectious – cholera
(c) Degenerative–cardio-vasculardisease
(d) Non-communicative – Parkinson’s disease.
explain the different approaches to the control and prevention of cholera
Cholera can best be controlled by the education of vulnerable people exposed to humid tropical environments where mosquitos thrive and the disease is endemic. Cholera spreads easily in areas of temporary housing without fresh water and good sanitation where transient populations live.
The advice given will control the spread and lower its mortality rate especially amongst under-5s.
* Effective hand-washing.
* Disinfection of areas of food preparation.
* Covering of disinfected water.
* Avoidance of shellfish.
* Thorough heating of food.
* Careful disposal of faeces.
* Separation of sewerage and water-supply systems.
* Treatment for serious cases involves the use of antibiotics.
* Oral rehydration therapy restores body fluid in all cases.
