Climatic geomorphology
27
and soil charts, but evidently there are clear relationships between them. A map of
morphoclimatic areas should be an original map in which the morphoclimate constitutes a
peculiar category of the natural phenomena (Tricart and Cailleux, 1965; Bfidel, 1977,
1982). It is also necessary to take into account that, except for the case of coastal
environments, the morphoclimatic boundaries are hardly sharp. There are, however,
physiographical areas, like the Black Forest, the Po plain and the Appalachian Mountains
that can be clearly differentiated (Btidel, 1977, 1982). In contrast, some transitional areas
(i.e. those between the savannas and semiarid areas on the African continent) can reach
huge dimensions. Only those areas corresponding to the cores of the different
morphoclimatic zones have no problems for their identification.
The main reviews on climatic geomorphology are those written by Btidel (1948, 1963,
1977) and Tricart and Cailleux (1965), which elaborated different maps of the postulated
morphoclimatic areas. Biidel (1948), using climatic and morphologic approaches,
divided the Earth into seven climatomorphological zones, illustrating this work with a
map of the distribution of these morphoclimatic zones in the "Old World" (Europe, Asia
and Africa). Tricart and Cailleux (1965) criticized this global zonation due to: (1) its
lack of homogeneity; (2) the segregation of three different permafrost regions; (3) the
consideration of the Mediterranean area as a single zone and (4) the use of a blurred
terminology. Bi.idel (1963) considered that the aclimatic factors (i.e. petrovariance or
change of bedrock resistance, epeirovariance or epeirogenesis, distance from base level,
topography), and human influences would play a relevant role in landscape evolution if
the Earth climate was uniform. These influences occur because the existing differences
between climatic zones are superior to these five aclimatic factors. For Btidel, on each
point on the Earth, climate determined the elemental combination of working
morphogenetic processes. From the effects produced in each climatic region, in which
these active complex morphogenetic processes operate, the Earth's surface can be
divided into five morphoclimatic zones (Fig. 1.11) not including the altitudinal climatic
gradient effects. This differentiation uses the morphologic approach as its main criteria,
which in turn is correlated to the climate. These morphoclimatic zones are denoted by
the modem climate, but for mid-latitude zones the influence of the past climates may be
relevant, because these zones undergo a slower geomorphic evolution.
The classification proposed by Tricart and Cailleux (1965) is based on two main
criteria: (1) The large climatic and biogeographic natural areas that provide the main
zonal boundaries; and (2) some subdivisions, assisted by the aforementioned set of criteria,
combined with palaeoclimatic differences. They differentiated the following areas, but
were only concerned with low-elevation zones where the altitudinal climatic gradient is
not relevant:
(1) Cold Zone.
(a) Glacier domain.
(b) Periglacial domain.
(2) Mid-latitude Forest Zone.
(a) Maritime domain with Quaternary glacial and periglacial landform heritage.
(b) Continental domain with the great influence of Quaternary and present-day ice
caps, with the possible occurrence of permafrost at depth.
(c) Mediterranean domain with a smaller influence of relict Quaternary landforms.
27
and soil charts, but evidently there are clear relationships between them. A map of
morphoclimatic areas should be an original map in which the morphoclimate constitutes a
peculiar category of the natural phenomena (Tricart and Cailleux, 1965; Bfidel, 1977,
1982). It is also necessary to take into account that, except for the case of coastal
environments, the morphoclimatic boundaries are hardly sharp. There are, however,
physiographical areas, like the Black Forest, the Po plain and the Appalachian Mountains
that can be clearly differentiated (Btidel, 1977, 1982). In contrast, some transitional areas
(i.e. those between the savannas and semiarid areas on the African continent) can reach
huge dimensions. Only those areas corresponding to the cores of the different
morphoclimatic zones have no problems for their identification.
The main reviews on climatic geomorphology are those written by Btidel (1948, 1963,
1977) and Tricart and Cailleux (1965), which elaborated different maps of the postulated
morphoclimatic areas. Biidel (1948), using climatic and morphologic approaches,
divided the Earth into seven climatomorphological zones, illustrating this work with a
map of the distribution of these morphoclimatic zones in the "Old World" (Europe, Asia
and Africa). Tricart and Cailleux (1965) criticized this global zonation due to: (1) its
lack of homogeneity; (2) the segregation of three different permafrost regions; (3) the
consideration of the Mediterranean area as a single zone and (4) the use of a blurred
terminology. Bi.idel (1963) considered that the aclimatic factors (i.e. petrovariance or
change of bedrock resistance, epeirovariance or epeirogenesis, distance from base level,
topography), and human influences would play a relevant role in landscape evolution if
the Earth climate was uniform. These influences occur because the existing differences
between climatic zones are superior to these five aclimatic factors. For Btidel, on each
point on the Earth, climate determined the elemental combination of working
morphogenetic processes. From the effects produced in each climatic region, in which
these active complex morphogenetic processes operate, the Earth's surface can be
divided into five morphoclimatic zones (Fig. 1.11) not including the altitudinal climatic
gradient effects. This differentiation uses the morphologic approach as its main criteria,
which in turn is correlated to the climate. These morphoclimatic zones are denoted by
the modem climate, but for mid-latitude zones the influence of the past climates may be
relevant, because these zones undergo a slower geomorphic evolution.
The classification proposed by Tricart and Cailleux (1965) is based on two main
criteria: (1) The large climatic and biogeographic natural areas that provide the main
zonal boundaries; and (2) some subdivisions, assisted by the aforementioned set of criteria,
combined with palaeoclimatic differences. They differentiated the following areas, but
were only concerned with low-elevation zones where the altitudinal climatic gradient is
not relevant:
(1) Cold Zone.
(a) Glacier domain.
(b) Periglacial domain.
(2) Mid-latitude Forest Zone.
(a) Maritime domain with Quaternary glacial and periglacial landform heritage.
(b) Continental domain with the great influence of Quaternary and present-day ice
caps, with the possible occurrence of permafrost at depth.
(c) Mediterranean domain with a smaller influence of relict Quaternary landforms.