HSC Geography flashcards
HSC Geography · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Ecosystem definition
- A community of interacting organisms together with the non-living environment they exchange energy and matter with. Boundaries are set by the observer, so scale matters.
- Biophysical components
- Atmosphere, hydrosphere, lithosphere, and biosphere. Each acts as a store of matter and energy, and transfers link them into cycles and flows.
- Ecological efficiency
- The proportion of energy at one trophic level that is transferred to the next. It averages about ten per cent, so food chains rarely exceed four or five links.
- Net primary production
- Gross primary production minus the respiration of producers. It represents the energy actually available to consumers and decomposers in an ecosystem.
- Nutrient cycling
- The movement of elements such as carbon, nitrogen, and phosphorus between living organisms and the physical environment. Decomposers return nutrients to soil and water.
- Negative feedback
- A process where a change triggers a response that counteracts it, promoting stability. An example is increased plant growth absorbing more atmospheric carbon dioxide.
- Positive feedback
- A process where a change amplifies itself, pushing a system further from its starting state. Melting ice reducing reflectivity and increasing warming is an example.
- Ecological resilience
- The capacity of an ecosystem to absorb disturbance and reorganise while retaining its essential structure and functions. Thresholds, once crossed, may produce irreversible change.
- Absolute versus relative location
- Absolute location uses fixed coordinates such as latitude and longitude. Relative location describes position in relation to other places, distances, or travel time.
- Spatial distribution
- The arrangement of phenomena across space, described by density, concentration, and pattern. Patterns may be clustered, dispersed, linear, or random.
- Natural increase rate
- Crude birth rate minus crude death rate, usually expressed per thousand people per year. It excludes migration, so it is not the same as total population change.
- Demographic transition model
- A model linking changes in birth and death rates to economic development. Populations move from high stationary through expanding stages to low stationary and possible decline.
- Population pyramid
- A paired bar graph of age groups by sex. Wide bases indicate high fertility; narrow bases and wide tops indicate ageing; bulges record past events such as migration.
- Push and pull factors
- Conditions driving people from a place (conflict, unemployment, disaster) and attracting them to another (work, safety, services). They explain migration direction and volume.
- Counter-urbanisation
- The movement of people from metropolitan areas to smaller towns and rural areas. It is driven by housing costs, lifestyle preference, and improved transport or remote work.
- Human wellbeing
- A multidimensional state including material living standards, health, education, security, and social connection. It is measured by composite indices rather than income alone.
- Human Development Index
- A composite index combining life expectancy, education (mean and expected years of schooling), and gross national income per capita, expressed between zero and one.
- Sustainability
- Meeting present needs without compromising the ability of future generations to meet theirs. It integrates environmental, social, and economic dimensions, often called the triple bottom line.
- Map scale
- The ratio between distance on a map and distance on the ground. A scale of 1:50,000 means one centimetre represents 500 metres.
- Large-scale map
- A map with a small representative fraction, such as 1:25,000. It shows a small area with high detail, including individual buildings and tracks.
- Small-scale map
- A map with a large representative fraction, such as 1:1,000,000. It shows a large area with generalised features and less detail.
- Contour interval
- The constant vertical distance between adjacent contour lines. It is stated in the map legend and determines the precision of elevation readings.
- Gradient formula
- Gradient equals vertical rise divided by horizontal run, with both in the same units. It is reported as a fraction, ratio, or percentage.
- Aspect
- The compass direction a slope faces. It affects solar exposure, temperature, moisture, and therefore vegetation and land use.
- Cross-section
- A profile drawn along a line on a map, plotting elevation against distance. It uses the same horizontal scale as the map, with vertical exaggeration stated.
- Areal interpolation
- Estimating values for one set of boundaries using data collected for different boundaries. It is common when census areas do not match the study area.
- Choropleth map
- A map shading whole regions by graded colours or patterns to represent a value. It shows rates or densities accurately but hides variation within each region.
- Isoline map
- A map joining points of equal value, such as contours for elevation or isohyets for rainfall. Close spacing indicates a steep gradient.
- Sampling methods
- Random sampling gives every site an equal chance; systematic sampling uses a fixed interval; stratified sampling divides the area into representative units before sampling.
- Fieldwork hypothesis
- A testable statement predicting a relationship between variables, such as distance from a stream and soil moisture. It must be measurable and falsifiable.
- Reliability versus validity
- Reliability is consistency of repeated measurements; validity is whether data actually measure the intended variable. Large samples improve reliability, not necessarily validity.
- GIS vector and raster
- Vector data represent points, lines, and polygons with coordinates. Raster data represent space as a grid of cells, suited to continuous surfaces such as elevation.