1. SCALES IN PHYSICAL GEOGRAPHY
The research process in Physical Geography (data, methodology, techniques, analysis) depends on the scale (spatial or temporal)
SPATIAL SCALES IN PHYSICAL GEOGRAPHY
Physical processes behave at various scales
Global
Continental
Regional
Local
Individual

2. SPATIAL SCALES IN PHYSICAL GEOGRAPHY
Regional
Global
Continental
Sao Paulo: 238 mm in January
Local
Individual

3. TEMPORAL SCALES IN PHYSICAL GEOGRAPHY (TIME CYCLES)
Daily
Monthly
Seasonally
Annual
Hundreds years
Tens –hundreds of thousands years
Millions of years
DAILY:
MONTHLY:
SST Anomaly March 2005

4. HUNDRED YEARS: ANNUAL: SEASONAL: MILLIONS YEARS: THOUSANDS YEARS:
Pangea (~225 million years ago)

5. SYSTEMS IN PHYSICAL GEOGRAPHY
A system is a set of relationships between features, processes or phenomena
Read: Strahler, Chapter2 (Systems in Physical Geography)
Natural Flow system
A system in which energy/matter move trough time from one location to another.
Ex:
Flow of energy from Sun to Earth (energy)
River system (matter)
Open flow systems: inputs and outputs of energy and matter
Closed flow systems: NO inputs or outputs

6. SYSTEMS
A system is a set of relationships between features, processes or phenomena linked by flows of energy and matter.
Read: Strahler, Chapter 2 (Systems in Physical Geography)
Ex: Hydrologic cycle

7. OPEN AND CLOSED SYSTEMS
Open systems: inputs and outputs of energy and matter.
Ex: the river system
precipitation
INPUT
river system
discharge to ocean
OUTPUT

8. OPEN AND CLOSED SYSTEMS
2. Closed systems: NO inputs or outputs. The flowing energy
and matter move endlessly. Ex: the hydrologic cycle

9. SYSTEM FEEDBACK
When flow (of matter or energy) in one pathway acts either to reduce or increase the flow in another pathway, reinforcing or reducing the initial flow.

10. FEEDBACK
causes
Initial condition
(matter/energy)
Another variables
changes in
causes changes in
Initial condition MODIFIED
(matter/energy)

11. This feedback can create instability, disruption.
POSITIVE FEEDBACK
If the flow is reinforced. There is an increased response in the system.
This feedback can create instability, disruption.
shrubs and wood dried
Wildfire
More fuel available
MORE fire

12. NEGATIVE FEEDBACK
If the flow is reduced. Further production in the system decreases the growth in the system.
This feedback causes a self-regulation in a natural system, stabilizing the system
Warmer Earth
More evaporation
More cloud formation
LESS warming
More reflection
of sunlight

13. SYSTEM EQUILIBRIUM
The flow rates in the pathways of a system remain about the same. The amounts of energy and matter within the system are constant.

14. Example: Positive or negative FEEDBACK?
VEGETATION REMOVED (overgrazing)
TRANSPIRATION?
RAINFALL ?
Less or more VEGETATION?

15. WHY ARE MAPS IMPORTANT ?
Maps are one of the most important tools in Geography.
They help us:
To visualize the “spherical” world on which we live
To place locations

16. To represent physical or human features (at different scales)
Ex: Physical features (precipitation distribution)
Regional
Global
Continental

17. Ex: Human features (population density)
Global
Continental
Regional

18. Ex: El Niño-Southern Oscillation (ENSO) impacts

19. IMPORTANT CONCEPTS Geographic Grid Latitude Longitude
Principal lines (Equator, Prime meridian)
Map projections
usually given in degrees (°)
GEOGRAPHIC GRID
Provides a system for locating places
on the Earth’s surface

20. LATITUDE
(parallels)
Define any location on Earth’s
surface in terms of how far north or south it is from the Equator (0° latitude)
Tells us if we are in the Northern or Southern Hemisphere (standard notation: 30° N, 55°S, max lat is 90°)
1° latitude = 111 km
Equator is a Great Circle.
All the other parallels are
small circles

21. LONGITUDE
(meridians)
Define any location on Earth’s
surface in terms of how far it is from the Prime Meridian (0° line of longitude)
Tells us if we are in the Western or Eastern Hemisphere (standard notation: 100° W, 15°E, max lon is 180°)
All meridians are half circles (unlike parallels)
1° longitude =111 km ONLY at the Equator (unlike latitude)

22. Together, latitude and longitude represent the location of any point on the earth’s surfaceB A

23. EXERCISE
Locate the following points and identify the principal physical feature
Lat: 40°N , Lon: 5°W
Lat: 15°N, Lon: 5°W
Lat: 10°S, Lon: 50°W
Lat: 40°N, Lon: 50°E
Lat: 20° N, Lon: 45°E
Lat: 30° S, Lon: 120°E

24. PRINCIPAL LINES
Prime Meridian
Equator
Tropic of Cancer
Tropic of Capricorn

25. CONTOUR MAPS A contour map is a map of isolines
Isoline: A line which connects points of equal value of a variable (temperature, precipitation, elevation , etc)

26. Isotherms
Isohyets

27. CONTOUR LINES INTERPRETATION
(CLIMATE VARIABLE)
Closely spaced contour lines represent a large gradient, widely spaced lines indicate small gradient
Gradient: the rate by which a variable changes spatially
Concentric circles of contour lines indicate a maximum or minimum value

28. Region with highest temperature?
Region with lowest temperature
Region with highest pressure gradient?
Region with lowest pressure gradient?
Region with strongest wind?
Region with lowest wind speed?
Regions with rainfall probability? (low pressure centers)