Earth Surface Processes - Concepts

Earth Surface Processes - Concepts

1. What is geomorphology

   • Geomorphology is the study of landforms and the processes that form them (Huggett, 2007).
   • Why is geomorphology important
     • Landscapes
       are
       shaped
       by
       movements
       of
       mass
     • Landscape
       shaping
       processes
       are
       influenced
       by
       many
       different
       factors
     • Landscape
       processes
       operate
       at
       many
       different
       scales
     • The
       Earth's
       landscapes
       are
       dynamic
     • Landscape
       dynamics
       are
       often
       complex
     • Landscapes
       are
       archives
       of
       the
       past
     • Global
       change
       is
       influencing
       landscape
       dynamics
     • Human
       activities
       are
       influencing
       landscape
       dynamics
     • The
       Earth's
       landscapes
       are
       becoming
       more
       hazardous
     • Successful
       environmental
       management
       needs
       geomorphological
       knowledge
   • Geomorphologists may study three key aspects of landforms: their form, process and history.
     • Process Geomorphology is the study of processes responsible for landform development (Huggett, 2007) e.g. sediment transport.
     • Historical Geomorphology is the study of landform history and landscape evolution through time.
     • Applied Geomorphology is the use of geomorphological techniques and knowledge for societal benefit e.g. flood risk.

2. Approaches in geomorphology

   • Geomorphic mapping & dating of landforms
     • LiDAR: High resolution mapping can lead to landscape re-interpretation
     • Satellite derived imagery & DEMs allow large spatial scales to be studied
   • Empirical data collection on processes: Field vs Lab
     • Empirical data is data obtained by observation or experimentation
   • Modelling (process and landforms)
     • Means of identifying key variables in earth surface processes as well as simulating future landform response (e.g. applied geomorphology).
   • Theoretical approaches
     • “[A scientific theory]…where a set of linked ideas is intended to provide a general explanatory framework…” in this case for an earth surface process. e.g. Bulls balance model

3. Key terms and concepts in geomorphology

   • Systems possess three components – elements, states and relations between elements and states.
     • Because a system is a set of parts there is therefore a boundary to a system e.g. watershed is an example of a physical boundary in the landscape
   • Equilibrium is a concept commonly applied to open systems in environmental science – “systems in which the quantities of stored energy or matter are adjusted so that input of energy or matter are balanced.” (Thomas and Goudie, 2000, p179.)
   • “A threshold of landform stability that is exceeded either by intrinsic change of the landform itself, or by a progressive change of an external variable” (Schumm, 1979 cited in Thomas and Goudie, 2000, p487)
   • Equifinality is where “a particular morphology (e.g. a landform can be generated by a number of alternative processes… or process histories.” (Thomas and Goudie, 2000, p178-179).