Revision Lecture

Question 1

who said ‘geography is primarily concerned to describe … the variable character of areas as formed by existing features in interrelationships’ ?

Answer 1

Hartshorne, 1939

Question 2

who said ‘Geography has to be conceived as the science concerned with the formulation of the laws governing the spatial distribution of certain features on the surface of the earth’

Answer 2

Schaefer, 1953

Question 3

What is Physical Geography?

Answer 3

Sub-discipline of Geography concerned with the study of processes and spatial patterns in the natural environment like the atmosphere, hydrosphere, cryosphere, biosphere, and geosphere, as opposed to the cultural or built environment, the domain of human geography.

Question 4

when was catastrophism?

Answer 4

until 1830s

Question 5

when was uniformitarianism?

Answer 5

1830-1930

Question 6

when was Davies’ Cycle of erosion

Answer 6

1890-1950

Question 7

what is ‘catastrophism’?

Answer 7

Ascribes the origin of Earth’s landforms to one or more “catastrophic” themes:

George Cuvier (1769-1832)
Robert Jameson (1774-1854)
Archbishop Ussher, 1650

Question 8

what is ‘uniformitarianism’?

Answer 8

Also termed Gradualism

“The present is the key to the past”
(coined by Whewell, 1832):

Natural processes shape landforms through
gradual changes over long periods of time.

Question 9

what is Davisian cycle of Erosion?

Answer 9

(a) young uplifted stage with very limited incision
(b) mature stage with deep valley incision and complex topography
(c) old eroded landscape with few topographic features

Question 10

what is ‘glacial theory’?

Answer 10

1846 - louis agassiz

• multiple glaciations
• most of northern europe in N America, N Asia, had been covered by ice sheets during a period later termed the pleistocene

Question 11

Dynamic equilibrium in stream flow (Gilbert 1877)

Question 12

Quantitative revolution (1950s): move to quantitative and statistical approaches (e.g. Arthur Strahler)

Question 13

Rejuvenation of equilibrium concept (Hack 1960)

Question 14

The Equilibrium Concept

Answer 14

Equilibrium over three timescales:
(a) dynamic equilibrium; b) steady-state equilibrium; (c) static equilibrium

Question 15

Climatic geomorphology (Julius Büdel, 1960s)

Question 16

1950s Advance in quantitative geography

Empiricism

Question 17

Cause – effect relationships (1970s)

The Scientific Method

Question 18

Magnitude – Frequency concept

Question 19

fieldwork strengths

Answer 19

• Measurements in ‘real world conditions’
• Gives better understanding of the system
• Observation together with measurements
• Changeable conditions
• No major limitations with scale of experiment

Question 20

fieldwork weaknesses

Answer 20

• Environmental conditions difficult to control
• Even for long-term experiments conditions may be non-representative (odd year)
• Equipment sometimes vandalised
• Challenging conditions: cold, hot, wet, insects..

Question 21

Lab work strengths

Answer 21

• Measurements in ‘controlled conditions’
• Very precise measurements of properties
• Not so restricted by logistics and time

Question 22

lab work weaknesses

Answer 22

• Difficulties in scaling up results from the laboratory to the field
• The simplicity of experiments ignore complex feedbacks and inter-linkages in the real world (similar to models)
• Difficult to judge how representative it is in real conditions

Question 23

remote sensing advantages

Answer 23

-Spatial coverage - Global
& Increasingly high resolution
- Regular repeat observations - Frequency depends on instrument and orbit
- Easy access to data - Most data is available over the internet
- Huge archive of data - Multi-decadal for some missions
- Variety of derived products

Question 24

remote sensing limitations

Answer 24

- Trade off between spatial and temporal resolution
Polar orbiting v geostationary
Swath width v resolution
- Large amount of data to handle
Can take time to download and process
- Length of time series
May not be as long as in-situ observations
- Continuity of observations
Instrument failure or mission lifetime

Question 25

what is modelling?

Answer 25

• Physical (process-based) and empirical (observation-based) models
• Tool for calculating consequences of a theory

Question 26

advantages of modelling

Answer 26

Allows testing of theories of how a system works

Question 27

disadvantages of modelling

Answer 27

• Simplified version of real world: ignore complex feedbacks and inter-linkages
• Models may predict correctly for the wrong reason

Question 28

Good” and “Bad Science”

Answer 28

• The dangerous powers of preconception
• Problems with statistical errors
• Problems with not using original, reliable sources
• Problems with being selective
• Be critical and examine all evidence

Question 29

what are scale issues?

Answer 29

Scale expansion via aerial and satellite remote sensing

BUT predictions at local scales remain uncertain, due to large spatial variability of natural environment.

Advance in fine-resolution techniques (microscopy including SEM and AFM)

BUT: problems of representativeness (up/down-scaling)

Key issue of establishing spatial and temporal representativeness

Number of samples depends on system variability

Sampling techniques
Random
Systematic
Stratified

Expanding the temporal scale

Space-for-time substitution