8
Climatic Geomorphology
out by Walther Penck (in 1920). At the beginning of the 20th century the prevailing idea
was that the wind was the main geomorphologic agent in the development of planation
surfaces in deserts (i.e. Hedin, Passarge, Walther). Bryan (1922), however, highlighted the
idea that wind action only introduces small modification to these planation surfaces.
Research on the work of wind carried out by Bagnold in the Egyptian desert was compiled
in his classic dissertation entitled The physics of aeolian sands and desert dunes. This work
constitutes a basis for the understanding of aeolian processes and the fundamentals of
aeolian geomorphology.
The work of the North American scientist Dana (in 1849) on the landforms developed
in the volcanic islands of the Central Pacific was the key for the initiation of tropical
geomorphology (Chorley et al., 1964). Previously, Thomson (in 1822) had pointed out
the occurrence of numerous isolated hills upstanding from the plains located in the
region of the Mozambique - Tanzania border (Douglas and Spencer, 1985a,b,c). Similar
observations were made by Bornhardt (in 1900) in eastern Africa, who introduced the term
inselberg to denote this kind of isolated hill. On the other hand, Darwin (in 1890) and
Branner (in 1896) highlighted the occurrence of thick weathering horizons, but previously
Buchanan (in 1807) had made the first scientific descriptions of laterite weathering
horizons developed in India. During the first half of the 20th century, concurring with the
exploration of new territories all around the world's climatic zones, different works on
tropical geomorphology were published (i.e. Cushing, Falconer, Grund, Hayes, Hubert,
Passarge, Sapper) (Douglas, 1978). In 1926 Thorbecke presided over the first meeting on
climatic geomorphology (Diisseldorf, Germany) in which the bases of morphoclimatic
classifications were established. The more relevant works of this period may be those
undertaken by the German scientist Freise during the decade of the 1930s in the State of
Rio de Janeiro (Brazil), and that of Sapper (in 1935) on the Geomorphology of the Humid
Tropics, which constituted the most relevant review of the time.
2.3. The impact of landscape evolution models on climatic geomorphology
The three existing models of landscape evolution, developed by Davis, Penck and King,
were proposed during different periods of the first half of the 20th century. The models of
Davis and King were particularly constrained to a specific climate, whereas the Penckian
model emphasized the role of tectonic and climatic factors together. Knowledge of all
the scientific works of these authors can lead to a better understanding of the content,
progressive development and criticisms represented by their models.
The life and work of William Morris Davis (1850-1934), emblematic geomorphologist and Professor of Geology at Harvard University, have been the subject of copious
analytic studies, some of them made with considerable extension and depth (Chorley
et al., 1973; King and Schumm, 1980). His more essential works, carried out until 1906,
were compiled in a Special Volume (Davis, 1954), but the scientific production of this
prolific scientist continued up to 1938, the date in which his last paper was published,
long after the first one published in 1880.
Davis graduated from Harvard University. After a 3-year long stay in Crrdoba,
Argentina and a journey around the world, he began his lectures at Harvard University in
1875. His research work was copious, always written in a clear and brilliant language,
Climatic Geomorphology
out by Walther Penck (in 1920). At the beginning of the 20th century the prevailing idea
was that the wind was the main geomorphologic agent in the development of planation
surfaces in deserts (i.e. Hedin, Passarge, Walther). Bryan (1922), however, highlighted the
idea that wind action only introduces small modification to these planation surfaces.
Research on the work of wind carried out by Bagnold in the Egyptian desert was compiled
in his classic dissertation entitled The physics of aeolian sands and desert dunes. This work
constitutes a basis for the understanding of aeolian processes and the fundamentals of
aeolian geomorphology.
The work of the North American scientist Dana (in 1849) on the landforms developed
in the volcanic islands of the Central Pacific was the key for the initiation of tropical
geomorphology (Chorley et al., 1964). Previously, Thomson (in 1822) had pointed out
the occurrence of numerous isolated hills upstanding from the plains located in the
region of the Mozambique - Tanzania border (Douglas and Spencer, 1985a,b,c). Similar
observations were made by Bornhardt (in 1900) in eastern Africa, who introduced the term
inselberg to denote this kind of isolated hill. On the other hand, Darwin (in 1890) and
Branner (in 1896) highlighted the occurrence of thick weathering horizons, but previously
Buchanan (in 1807) had made the first scientific descriptions of laterite weathering
horizons developed in India. During the first half of the 20th century, concurring with the
exploration of new territories all around the world's climatic zones, different works on
tropical geomorphology were published (i.e. Cushing, Falconer, Grund, Hayes, Hubert,
Passarge, Sapper) (Douglas, 1978). In 1926 Thorbecke presided over the first meeting on
climatic geomorphology (Diisseldorf, Germany) in which the bases of morphoclimatic
classifications were established. The more relevant works of this period may be those
undertaken by the German scientist Freise during the decade of the 1930s in the State of
Rio de Janeiro (Brazil), and that of Sapper (in 1935) on the Geomorphology of the Humid
Tropics, which constituted the most relevant review of the time.
2.3. The impact of landscape evolution models on climatic geomorphology
The three existing models of landscape evolution, developed by Davis, Penck and King,
were proposed during different periods of the first half of the 20th century. The models of
Davis and King were particularly constrained to a specific climate, whereas the Penckian
model emphasized the role of tectonic and climatic factors together. Knowledge of all
the scientific works of these authors can lead to a better understanding of the content,
progressive development and criticisms represented by their models.
The life and work of William Morris Davis (1850-1934), emblematic geomorphologist and Professor of Geology at Harvard University, have been the subject of copious
analytic studies, some of them made with considerable extension and depth (Chorley
et al., 1973; King and Schumm, 1980). His more essential works, carried out until 1906,
were compiled in a Special Volume (Davis, 1954), but the scientific production of this
prolific scientist continued up to 1938, the date in which his last paper was published,
long after the first one published in 1880.
Davis graduated from Harvard University. After a 3-year long stay in Crrdoba,
Argentina and a journey around the world, he began his lectures at Harvard University in
1875. His research work was copious, always written in a clear and brilliant language,