Introduction to Geomorphology

1
Introduction to Geomorphology

• Geography 2106 Geomorphology
• Nipissing University
• 2008

2
Overview

• What is Geomorphology?
• Development of Geomorphology
• Process Geomorphology
• Systems Approach
• Driving and Resisting Forces

3
What is Geomorphology?

• a) The study of the morphology or form of the
  Earths surface
• b) Defn
• The study of landforms on or near the Earths
  surface and the processes working on them.

4
What is Geomorphology?

• c) A discipline w/ close ties to other
  sub-disciplines in Physical Geography and the
  Earth Sciences
• d) It is a science, but it has strong
  "connections" w/ the humanities
• e) Taught w/in Geography or Geology

5
Development of Geomorphology

• a) In the 17th early 18th century, surface
  features of the earth were commonly attributed
  to catastrophic, often biblical-like events
• - a school of thought referred to as
  "catastrophism"

6
Development of Geomorphology

• b) During the late 18th 19th century, the
  works of Hutton, Playfair, Lyell introduced the
  concept of uniformitarianism
• c) By the late 19th century, Gilbert postulated
  that landforms reflect an adjustment btwn
  geomorphic processes and geology

7
Development of Geomorphology

• d) But geomorphologists were lured away by the
  Davisian model of landform development (see fig
  1.1)

8
Development of Geomorphology

• e) By the mid 20th century, there was a return to
  the importance of the relationship btwn form and
  process
• - fuelled in large part by the quantitative
  revolution

9
Development of Geomorphology

• f) The concept of dynamic equilibrium was
  re-born, as landforms were seen as adjusting to
  the processes operating on the geology
• - and consequently, process and form share a
  cause and effect relationship
• g) The emphasis on form and process led to the
  development of Process Geomorphology

10
Process Geomorphology

• a) A dynamic equilibrium exists btwn landforms
  and processes, but it is continually being
  adjusted
• - driving forces vs. resisting forces
• b) Major changes in the driving forces may
  disrupt the equilibrium temporarily or result in
  a new equilibrium

11
Process Geomorphology

• c) Processes are multivariate and interrelated
• d) Process Magnitude Frequency
• e) Different time frames for the study of
  geomorphic systems see fig 1.5

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Process Geomorphology

• f) Complexities
• i) Thresholds
• ii) Stores
• iii) Non-linear relationships
• iv) Multiple relationships

13
Systems Theory

• Defn
• A system is a collection of related components
  interconnected by flows of energy and matter
• - e.g. a drainage basin
• The flows of energy and matter are dynamically
  balanced by the system w/in certain thresholds,
• i.e. a dynamic equilibrium

14
Systems Theory

• c) Types of Thresholds
• Extrinsic threshold
• Intrinsic threshold
• d) Responses
• Negative Feedback
• Positive Feedback
• Complex Responses
• (see fig 1.4)

15
Systems Theory

• e) Advantages for Geomorphology
• i) Emphasis can be placed on the relationship
  btwn form and process
• ii) Stresses the multivariate nature of
  geomorphology
• iii) Balance is a dynamic concept
• iv) Time