Praxis Geography cheat sheet

Five themes (Geography Education National Implementation Project): location, place, human-environment interaction, movement, region - a framework for organizing questions, not a formal theory.

Location splits into absolute (a fixed grid coordinate such as latitude/longitude or a projected easting/northing) and relative (position described against other features, e.g., 'downstream of the confluence').

Place = human and physical characteristics that make a locale distinct; region = an area unified by one or more shared traits, so the same land can belong to many overlapping regions.

Region types: formal (uniform, measurable trait such as a climate zone or language area), functional (nodal, organized around a core and its flow field, e.g., a commuter shed), perceptual (vernacular, defined by popular image).

Scale is a decision rule: a phenomenon can look clustered at one scale and dispersed at another, so always state the scale of analysis; the modifiable areal unit problem warns that boundaries change results.

Map projections trade off: conformal preserves local angles/shapes, equal-area preserves size ratios, equidistant preserves distance from one or two points, and compass (azimuthal) preserves direction from a center.

Large-scale maps show small areas in high detail (e.g., 1:24,000); small-scale maps show large areas in low detail (e.g., 1:5,000,000). A representative fraction has no units, so it works in any measurement system.

Diffusion types: relocation (carried by migrating people), expansion - contagious (nearby contact), hierarchical (large centers to smaller ones), stimulus (idea adapted rather than copied).

Distance-decay and Tobler's first law (near things are more related than distant things) underpin interaction models such as gravity and spatial interaction.

Earth's rotation (west to east, ~24 h) causes day/night and the Coriolis deflection; revolution plus 23.5° axial tilt causes seasons and the migration of the subsolar point between 23.5° N and 23.5° S.

Equinoxes (~March 21, ~September 22): subsolar point at the equator, 12-hour day everywhere. Solstices (~June 21, ~December 22): subsolar point at a tropic, longest/shortest day of the year in each hemisphere.

Pressure belts and winds: equatorial low (ITCZ), subtropical highs near 30°, subpolar lows near 60°, polar highs; surface winds blow from high to low pressure, deflected right in the Northern Hemisphere and left in the Southern.

Climate controls: latitude, altitude, continentality, ocean currents, prevailing winds, and topographic barriers. Windward slopes are wet (orographic lift); leeward slopes are dry (rain shadow).

Plate boundaries: divergent (new crust, mid-ocean ridges, rift valleys), convergent (subduction, trenches, volcanic arcs, or continental collision and fold mountains), transform (lateral slip, e.g., San Andreas).

Rock classes: igneous (cooled magma/lava), sedimentary (deposited and lithified layers, the main fossil and aquifer host), metamorphic (heat and pressure alter pre-existing rock).

Fluvial work: erosion by abrasion, hydraulic action, and solution; transport of bedload by saltation and traction; deposition where gradient or discharge falls, producing deltas, alluvial fans, and floodplains.

Glacial landforms: erosional (cirque, arête, U-shaped valley, hanging valley) versus depositional (moraine, drumlin, esker, outwash plain); continental ice sheets scoured and flattened high-latitude terrain.

Demographic transition model stages: high birth/high death (stage 1), early expanding with falling death rates (2), late expanding with falling births (3), low stationary (4); some models add a stage 5 of below-replacement fertility.

Population pyramids read structure: broad base = high fertility and young dependency; narrowing base with a wide top = aging population and rising old-age dependency ratios.

Doubling time ≈ 70 ÷ annual growth rate in percent (rule of 70); natural increase = crude birth rate − crude death rate, expressed per 1,000.

Push–pull migration: Ravenstein's laws include short-step moves, streams and counterstreams, urban-rural net direction, and the tendency of migrants to be young adults; intervening obstacles can block movement.

Settlement patterns: clustered/nucleated (resources, defense, fertile nodes), dispersed (isolated farmsteads), linear (along a road, river, or coast).

Von Thünen rings: land use intensity falls with distance from market because transport cost rises; perishable or bulky products sit closest.

Central place theory: settlements provide goods of different ranges and thresholds; higher-order centers are fewer and spaced farther apart, each serving a hexagonal hinterland.

Political geography: compact, elongated, prorupt, perforated, and fragmented state shapes; boundaries are antecedent, subsequent, superimposed, or relic; the exclusive economic zone extends 200 nautical miles from the baseline.

Economic sectors: primary (extraction), secondary (manufacturing), tertiary (services), quaternary (knowledge/research); the New International Division of Labor moved labor-intensive production to lower-wage regions.

Tragedy of the commons: open-access resources with no exclusion mechanism are overused; solutions rely on privatization, regulation, or community (common-pool) management with clear boundaries and monitoring.

Sustainable development: meeting present needs without compromising future generations' ability to meet theirs; assessed through three pillars - environmental, economic, social.

Land-use change and deforestation are leading drivers of biodiversity loss and carbon emissions; edge effects reduce habitat quality where fragments border cleared land.

Water stress indicators: per-capita renewable supply, withdrawal-to-availability ratio; irrigation is the largest consumptive use of freshwater globally.

Energy: fossil fuels dominate global primary supply; renewable share grows fastest in electricity. Environmental costs differ by source (combustion emissions vs. land use and intermittency).

Environmental hazards: risk ≈ hazard × exposure × vulnerability; vulnerability depends on wealth, building codes, warning systems, and social factors, not only on hazard magnitude.

Anthropogenic climate forcing: greenhouse gases (CO2, CH4, N2O, halocarbons) trap outgoing longwave radiation; feedbacks such as ice-albedo loss and permafrost methane release amplify warming.

Political ecology and environmental justice: costs and benefits of resource use fall unevenly across income, race, and region; siting of waste and extraction facilities is a recurring justice issue.

Ecological footprint compares demand on productive land and water with biocapacity; overshoot occurs when footprint exceeds available biocapacity.

Latitude: 0° equator to 90° N/S; longitude: 0° prime meridian to 180° E/W. Degrees are subdivided into 60 minutes and minutes into 60 seconds; 1 minute of latitude ≈ 1 nautical mile (1.852 km).

Scale conversion: map distance ÷ ground distance; a bar scale survives resizing and a representative fraction does not need units, so convert consistently (e.g., 1:50,000 means 1 cm = 0.5 km).

Contour rules: closely spaced contours = steep slope; hachures or V-points pointing uphill mark depressions or valleys; contours never cross.

Remote sensing: passive sensors detect reflected or emitted energy (visible, thermal); active sensors (radar, lidar) emit energy and time the return, so they work at night and through cloud.

GIS layers: vector data (points, lines, polygons) represent discrete features; raster data (cells) represent continuous fields such as elevation or land cover; a DEM stores elevation in a grid.

GPS/GNSS trilateration uses timing signals from at least four satellites to solve for latitude, longitude, altitude, and clock error.

Sampling and inference: identify the unit of analysis, watch for ecological fallacy (inferring individual behavior from aggregate data) and spatial autocorrelation that inflates apparent significance.

Cartographic communication: classify data (equal interval, quantile, natural breaks) deliberately, use choropleth only for standardized rates (not raw counts), and match symbol type to data level.

Five themes (Geography Education National Implementation Project): location, place, human-environment interaction, movement, region - a framework for organizing questions, not a formal theory.

Location splits into absolute (a fixed grid coordinate such as latitude/longitude or a projected easting/northing) and relative (position described against other features, e.g., 'downstream of the confluence').

Place = human and physical characteristics that make a locale distinct; region = an area unified by one or more shared traits, so the same land can belong to many overlapping regions.

Region types: formal (uniform, measurable trait such as a climate zone or language area), functional (nodal, organized around a core and its flow field, e.g., a commuter shed), perceptual (vernacular, defined by popular image).

Scale is a decision rule: a phenomenon can look clustered at one scale and dispersed at another, so always state the scale of analysis; the modifiable areal unit problem warns that boundaries change results.

Map projections trade off: conformal preserves local angles/shapes, equal-area preserves size ratios, equidistant preserves distance from one or two points, and compass (azimuthal) preserves direction from a center.

Large-scale maps show small areas in high detail (e.g., 1:24,000); small-scale maps show large areas in low detail (e.g., 1:5,000,000). A representative fraction has no units, so it works in any measurement system.

Diffusion types: relocation (carried by migrating people), expansion - contagious (nearby contact), hierarchical (large centers to smaller ones), stimulus (idea adapted rather than copied).

Distance-decay and Tobler's first law (near things are more related than distant things) underpin interaction models such as gravity and spatial interaction.

Earth's rotation (west to east, ~24 h) causes day/night and the Coriolis deflection; revolution plus 23.5° axial tilt causes seasons and the migration of the subsolar point between 23.5° N and 23.5° S.

Equinoxes (~March 21, ~September 22): subsolar point at the equator, 12-hour day everywhere. Solstices (~June 21, ~December 22): subsolar point at a tropic, longest/shortest day of the year in each hemisphere.

Pressure belts and winds: equatorial low (ITCZ), subtropical highs near 30°, subpolar lows near 60°, polar highs; surface winds blow from high to low pressure, deflected right in the Northern Hemisphere and left in the Southern.

Climate controls: latitude, altitude, continentality, ocean currents, prevailing winds, and topographic barriers. Windward slopes are wet (orographic lift); leeward slopes are dry (rain shadow).

Plate boundaries: divergent (new crust, mid-ocean ridges, rift valleys), convergent (subduction, trenches, volcanic arcs, or continental collision and fold mountains), transform (lateral slip, e.g., San Andreas).

Rock classes: igneous (cooled magma/lava), sedimentary (deposited and lithified layers, the main fossil and aquifer host), metamorphic (heat and pressure alter pre-existing rock).

Fluvial work: erosion by abrasion, hydraulic action, and solution; transport of bedload by saltation and traction; deposition where gradient or discharge falls, producing deltas, alluvial fans, and floodplains.

Glacial landforms: erosional (cirque, arête, U-shaped valley, hanging valley) versus depositional (moraine, drumlin, esker, outwash plain); continental ice sheets scoured and flattened high-latitude terrain.

Demographic transition model stages: high birth/high death (stage 1), early expanding with falling death rates (2), late expanding with falling births (3), low stationary (4); some models add a stage 5 of below-replacement fertility.

Population pyramids read structure: broad base = high fertility and young dependency; narrowing base with a wide top = aging population and rising old-age dependency ratios.

Doubling time ≈ 70 ÷ annual growth rate in percent (rule of 70); natural increase = crude birth rate − crude death rate, expressed per 1,000.

Push–pull migration: Ravenstein's laws include short-step moves, streams and counterstreams, urban-rural net direction, and the tendency of migrants to be young adults; intervening obstacles can block movement.

Settlement patterns: clustered/nucleated (resources, defense, fertile nodes), dispersed (isolated farmsteads), linear (along a road, river, or coast).

Von Thünen rings: land use intensity falls with distance from market because transport cost rises; perishable or bulky products sit closest.

Central place theory: settlements provide goods of different ranges and thresholds; higher-order centers are fewer and spaced farther apart, each serving a hexagonal hinterland.

Political geography: compact, elongated, prorupt, perforated, and fragmented state shapes; boundaries are antecedent, subsequent, superimposed, or relic; the exclusive economic zone extends 200 nautical miles from the baseline.

Economic sectors: primary (extraction), secondary (manufacturing), tertiary (services), quaternary (knowledge/research); the New International Division of Labor moved labor-intensive production to lower-wage regions.

Tragedy of the commons: open-access resources with no exclusion mechanism are overused; solutions rely on privatization, regulation, or community (common-pool) management with clear boundaries and monitoring.

Sustainable development: meeting present needs without compromising future generations' ability to meet theirs; assessed through three pillars - environmental, economic, social.

Land-use change and deforestation are leading drivers of biodiversity loss and carbon emissions; edge effects reduce habitat quality where fragments border cleared land.

Water stress indicators: per-capita renewable supply, withdrawal-to-availability ratio; irrigation is the largest consumptive use of freshwater globally.

Energy: fossil fuels dominate global primary supply; renewable share grows fastest in electricity. Environmental costs differ by source (combustion emissions vs. land use and intermittency).

Environmental hazards: risk ≈ hazard × exposure × vulnerability; vulnerability depends on wealth, building codes, warning systems, and social factors, not only on hazard magnitude.

Anthropogenic climate forcing: greenhouse gases (CO2, CH4, N2O, halocarbons) trap outgoing longwave radiation; feedbacks such as ice-albedo loss and permafrost methane release amplify warming.

Political ecology and environmental justice: costs and benefits of resource use fall unevenly across income, race, and region; siting of waste and extraction facilities is a recurring justice issue.

Ecological footprint compares demand on productive land and water with biocapacity; overshoot occurs when footprint exceeds available biocapacity.

Latitude: 0° equator to 90° N/S; longitude: 0° prime meridian to 180° E/W. Degrees are subdivided into 60 minutes and minutes into 60 seconds; 1 minute of latitude ≈ 1 nautical mile (1.852 km).

Scale conversion: map distance ÷ ground distance; a bar scale survives resizing and a representative fraction does not need units, so convert consistently (e.g., 1:50,000 means 1 cm = 0.5 km).

Contour rules: closely spaced contours = steep slope; hachures or V-points pointing uphill mark depressions or valleys; contours never cross.

Remote sensing: passive sensors detect reflected or emitted energy (visible, thermal); active sensors (radar, lidar) emit energy and time the return, so they work at night and through cloud.

GIS layers: vector data (points, lines, polygons) represent discrete features; raster data (cells) represent continuous fields such as elevation or land cover; a DEM stores elevation in a grid.

GPS/GNSS trilateration uses timing signals from at least four satellites to solve for latitude, longitude, altitude, and clock error.

Sampling and inference: identify the unit of analysis, watch for ecological fallacy (inferring individual behavior from aggregate data) and spatial autocorrelation that inflates apparent significance.

Cartographic communication: classify data (equal interval, quantile, natural breaks) deliberately, use choropleth only for standardized rates (not raw counts), and match symbol type to data level.