BRIEF HISTORY & BASIC CONCEPTS

A. Introduction

• geomorphology: the study of landforms

B. Brief History

1. Uniformitarianism

• the present is the key to the past

2. W.M. Davis' Geographical Cycle

3. Process Geomorphology

• J.W. Powell

• G.K. Gilbert

C. Geomorphology Since the 1950s

1. Process geomorphology & systems analysis

2. Applied geomorphology

3. Quantification in geomorphology

D. Basic Concepts in Process Geomorphology

1. Equilibrium

• driving framework: climate, gravity & internal heat

• resisting framework: lithology & geologic structure

• equilibrium

  • results from balance between driving and resisting forces

  • implies landforms exist in an unchanging condition

  • form remains constant provided fundamental controls don't change

2. Thresholds: the limits of equilibrium

• what is temporary disequilibrium & what is geomorphologically significant disequilibrium?

• complex responses

3. Equilibrium and time

definition of equilibrium is time dependent

• static equilibrium: landforms truly don't change (hours, days, months)

• steady-state equilibrium: changes occur, but system maintains a constant average condition (100s to 1000s of years)

• dynamic equilibrium: system changes progressively (millions of years)

4. Systems approach

a. morphological systems

b. cascading systems

c. process-response systems

E. Summary

• brief history: uniformitarianism, climatic geomorphology, geographical cycle, process geomorphology

• basics to process geomorphology: equilibrium, time, thresholds, systems