- A morphogenetic region is a region where the dominant geomorphic processes, under certain climatic conditions, contribute to distinctive landscape characteristics that contrast with other regions formed under different climates. - The concept is based on the idea that each climate produces characteristic landforms through its influence on processes like weathering, erosion, and runoff. - Morphogenetic regions are defined by identifying major climatic/zoogeographical regions and the diagnostic landforms within them that reflect the dominant geomorphic processes operating under those particular climatic conditions.

1. Morphogenetic region
A region in which, under certain climatic conditions, the
predominant geomorphic processes will contribute regional
characteristics of landscape that contrast with those of other
regions formed under different climatic conditions.
The concepts of climatic geomorphology and morpho-
climatic/morphogenetic landscapes and regions was
enriched by the classical work of J. Budel (1948, 1982), L.C.
Peltier (1950), C. Troll (1958), W.F. Tanner (1961), P. Birot
(1968), D.R. Stoddart (1969), L. Wilson (1969, 1973), J.
Tricart and A. Cailleux (19720 etc.
They argue that the rate of operation of weathering and
erosional processes, vegetation type, surface runoff, nature,
and rate of erosion and mechanisms of landform genesis
and development differ considerably from one climatic
region to the other but it may be pointed out that they could
not be able to present convincing evidences in support of

2. • Morphogenetic regions
• The concept of morphogenetic/morphoclimatic regions is
based on the basic concept of climatic geomorphology
that ‘each geomorphic process produces its own
characteristic assemblage of landforms, and each
geomorphic process is the result of a particular climate’
and thus, each climatic type produces its own
characteristic assemblage of distinctive landforms.
According to Chorley et. Al. (1985) morphogenetic
regions are large areal units within which distinctive
associations of geomorphic processes (weathering, frost
action, mass movements, fluvial action and wind action)
are assumed to operate, tending towards a state of
morphoclimatic equlibrium wherein regional landforms
reflect regional climates.”
• The following criteria for the determination and definition
of morphogenetic regions-
• A. Identification and classification of major
morphogenetic regions on the basis of major climatic
and zoogeographical regions.
•

3. their arguments as yet.
The concept of climatic geomorphology is based on the
following three major themes (d.R. Stoddart, 1969)-
1. Landforms differ significantly in different climatic regions.
2. Spatial variations of landforms in different climatic regions
are because of spatial variations in climatic parameters
(tempt., humidity, precipt. etc.) and their influences on
weathering, erosion and runoff.
3. Quaternary climatic changes could not obscure
relationships between landforms and climates. In other
words, there are certain diagnostic landforms which
clearly demonstrate climate-landforms relationships.
Diagnostic landforms:
The advocates of climatic geomorphology have attempted
to collect information about the characteristics of such
landforms which may be regarded as diagnostic landforms
to determine climate-landforms relationships.

4. Such typical diagnostic landforms are regarded as
representatives of a particular climate. Climatogenetic or
climatically controlled landforms are identified and
differentiated in two ways, (i) general observation of whole
landscape of each climatic region (ii) identification of
typical or distinctive landforms which represent the control
of a particular climate. Such distinctive landforms are
designated as ‘diagnostic landforms’.
Inselbergs representing steep side residual hills are
considered to be the representative landforms of hot and
arid and semi-arid climates and the end product of arid
cycle of erosion. But inselbergs are found in different parts
of the world having different ‘climatic conditions’ from
humid subtropical in Georgia, North America to humid
tropical in the Guinea coastlands, south India, Brazil and
to Desert areas in western North America, Mauretania,
and South-west Africa. It is argued that inselbergs are
structurally controlled rather than climatically controlled
and most of the present inselbergs were formed before
Quaternary epoch.

5. An inselberg is a residual relief feature--an isolated hill, ridge, or small mountain
that rises abruptly, like an island, from a gently sloping or virtually level
surrounding plain (inselberg is a German word meaning "island mountain").

6. • A tor is a rock outcrop formed by weathering, usually
found on or near the summit of a hill. In the
South West of England, where the term originated, it is
also a word used for the hills themselves – particularly
the high points of Dartmoor in Devon and Bodmin Moor
in Cornwall.

7. It may be possible that inselbergs might have been formed
when the climate was arid or semi-arid which might have
changed after their formation.
Pediments, characterised by low-angle rock-cut surfaces
surrounding mountains, are considered to be the
representative landforms of arid and semi-arid climates.
Pediments are also found in a variety of climatic conditions
e.g. tropical wet and dry climate, subtropical and temperate
climate. Penck argue that pediments are structurally and
tectonically controlled rather than climatically. King has
opined that the process of pediplanation and pedimentation
is universal and it occurs in all environmental conditions.
It may be concluded that the aforesaid diagnostic landforms
are older than Pleistocene climatic changes, so they are
definitely not related to present climates where they are
found.
Geomorphic processes and climatic controls
It is fact that different processes work different climatic

8. regions and with climatic variations there is also variability in the
nature and mode of influences of climatic parameters which affect
denudational (weathering and erosional) processes.

9. • Temperature and humidity have emerged as the most
significant climatic parameters of the control of
geomorphological processes in different climatic regions. High
mean annual temperature and rainfall favour deep chemical
weathering in humid tropics.
• Besides, vegetation also plays important role in controlling
geomorphic processes in tropical humid areas, because the
combination of high mean annual temperature and rainfall
favour dense vegetation even on steeper slopes with the result
the processes of soil erosion, sheetwash and physical
weathering are considerably slowed down.
• Dense vegetation of humid tropics also reduces surface runoff
because a sizeable portion of rainfall is intercepted by forest
canopy and thus rainwater reaches the ground surface in the
form of aerial streamlets through the leaves, twigs, branches
and stems of trees and thus allows more infiltration.

12. • T. C. Chamberlin and R. T. Chamberlin (1910) differentiated
landforms of humid tropics from those of the mid-latitude
temperate landforms. Different rock types respond
differently to the combinations of water and temperature in
different climates. Limestones become chemically weak to
weathering and erosion in hot and humid climate because
chemical weathering becomes more active but these
become resistant to chemical weathering in hot and arid
climate because of scarcity of water and humidity.
• Direct controls of climate
• The different morphogenetic processes operate in different
climatic variation. The mode and rate of operation of
geomorphic processes also differ from one climatic region to
the other. Besides weathering, climate also influences the
mechanisms of transportation and deposition.
• Temperature is a very significant climatic parameter which
not only influences but also controls the mechanisms of
different morphogenetic processes. It is known to all that

13. • Temperature varies considerably in different climatic
regions. If temperature of a region is below freezing point
during night but rises above freezing point during day time
then there occurs diurnal freeze and thaw cycle which
leads to alternate processes of contraction and expansion.
The repetition of this mechanism causes frost weathering
in periglacial climate ( solifluction) during transitional
periods of summer and winter seasons.
• Exfoliation…
• Indirect climate controls
• (Climate vegetation Morphogenetic processes)
• Climate influences and controls morphogenetic processes
indirectly through 1. vegetation and 2. soils. The world
distribution of vegetation is azonal which is closely related
to climate zones. Climate and soils are so intimately
interrelated that influence each other. Vegetation
determines pedogenesis while soils determine vegetation
types which again depend on climate. Vegetation, in turn,

15. • In geology, solifluction, also known as soil fluction, is a type of
mass wasting where waterlogged sediment moves slowly
downslope, over impermeable material.

16. • Also influences floral characteristics. These interactions
between climate, soils and vegetation, in turn, influence
and control nature, type and mode of operation of different
denudational processes.
• The kinetic energy of rainfall (say raindrop) and its
geomorphic significance is greatly controlled by
interception capacity of vegetation. It may be pointed out
that the areas devoid of vegetation (open areas) are
directly affected by falling raindrops with maximum kinetic
energy and causes splash erosion wherein loose particles
are resettled on the ground surface which discourages
infiltration of rainwater and favours increased surface
runoff. On the other hand, densely vegetated areas mainly
of forests are characterised by least splash erosion
because of maximum interception of rainwater. There is
maximum interception of rainwater in equatorial rainforests
of humid tropics wherein ‘aerial streams’ become most
effective.

17. • Climate vegetation Soil and
Morphogenetic processes
• It may be mentioned that climate influences vegetation and
in turn vegetation influences soils and morphogenetic
processes. It may be pointed out that it is not necessary that
climate always influences morphogenetic processes via
vegetation and soils. Thus, the following relationships
between these variables may be identified 1. climate
vegetation morphogenetic processes landforms
• 2. climate soils morphogenetic processes landforms
• 3. climate morphogenetic processes landforms

18. • Morphogenetic regions
• The concept of morphogenetic/morphoclimatic regions is
based on the basic concept of climatic geomorphology
that ‘each geomorphic process produces its own
characteristic assemblage of landforms, and each
geomorphic process is the result of a particular climate’
and thus, each climatic type produces its own
characteristic assemblage of distinctive landforms.
According to Chorley et. Al. (1985) morphogenetic
regions are large areal units within which distinctive
associations of geomorphic processes (weathering, frost
action, mass movements, fluvial action and wind action)
are assumed to operate, tending towards a state of
morphoclimatic equlibrium wherein regional landforms
reflect regional climates.”
• The following criteria for the determination and definition
of morphogenetic regions-
• A.Identification and classification of major morphogenetic
regions on the basis of major climatic and
zoogeographical regions.
•

19. • B. Subdivision of major morphogenetic region on the
basis of present climatic, zoogeographical and
paleoclimatic factors.
• On the basis of these two criteria they divided the globe
into 4 major morphogenetic regions and 9 sub-regions as
follows:
• 1. Cold zone morphogenetic regions
• a. glacial zone –characterized by runoff in solid form e.g.
glaciers
• b. periglacial zone- characterized by runoff in liquid form-
water during summer.
• 2. Forested zone morphogenetic regions
• a. Maritime zone: normal winter season, no significant
frost action, more influence of Pleistocne glacial and
periglacial relict features.
• b. continental zone: winter severely cold, effects of
Pleistocene and present frost most dominant.

20. • c. mediterranean zone: dry summer, wet winter, insignificant effects of
Quaternary periglacial relict feature.
• 3. Semi-arid and Arid morphogenetic regions:
• (A) on the basis of aridity
• (a) stepe regions
• (b) xerophytic region
• (c) desert region
• (B) on the basis of winter temperature
• (a) middle latitude region
• (b) subtropical region
• (c) tropical region
• 4. Humid Tropical morphogenetic regions
• (a) savana region: dry and wet seasons, seasonal rainfall, moderate
vegetation cover, enough overland flow, active chemical weathering
during wet season.
• (b) forest region: humid tropical region, rainfall throughout
• The year, maximum vegetation cover, chemical and biological
weathering most dominant.

22. The Köppen climate classification is one of the most widely used
climate classification systems. It was first published by Crimea
German climatologist W. Köppen in 1884.
• Köppen's scheme uses five basic types of climate:
• A: humid tropical
• B: dry
• C: humid mesothermal
• D: humid microthermal
• E: polar/arctic
• Taking into account temperature and precipitation, some 23 more-
precise categories can be devised.
• A-- tropical (coldest 18°C) --Af: moist, Am: monsoon; Aw: winter dry
period
• B-- no temperature limitation ; BS: steppe; BW: desert
• C-- mesothermal (-3°C to 18°C); Cf: moist; precipitation distributed
throughout year; Cw: winter dry period; Cs: summer dry period
• D-- microthermal ( < -3°C to 18°C) ; Df: moist; precipitation distributed
throughout year, Dw: winter dry period
• E-- arctic (warmest < 10°C)

24. • Glaciers
• Types of Glaciers
• An ice age is a period
of time when much of
earth's land is covered
in glaciers.
• A glacier is a thick ice
mass that forms over
hundreds of thousands
of years.

25. • Valley
Glaciers
• Valley Glaciers
are ice masses
that slowly
advance down
valleys that
were originally
occupied by
streams. It is a
stream with ice
that flows
between steep
rock walls from
a place near
the top of a
mountain
valley.

26. • Horns
• Horns are sharp pyramid like peaks

30. Alluvial fans are fan-shaped deposits of water-transported material
(alluvium). They typically form at the base of topographic features
where there is a marked break in slope. Consequently, alluvial fans
tend to be coarse-grained, especially at their mouths. At their
edges, however, they can be relatively fine-grained.

31. • Most Desert stream dry up before they reach the ocean.
• Interior drainage into basin produces:
• - alluvial fans- a cone of debris

32. • Playa lakes- a flat area on the floor of an
undrained desert basin that fills and
becomes a lake after heavy rain.
Bajada: Gently sloping depositional plain between pediments and playa
is called bajada.

33. • Landscapes Shaped by Wind
• Wind Erosion
• Wind erodes in the desert 2 ways:
• - deflation, is the lifting and removal of loose particles
such as clay and silt.
• - abrasion, happens when wind blown sand cuts and
polishes exposed rock surfaces.
• Wind Deposits
• The wind can create landforms when it deposits its
sediments especially in deserts and along coast. both
layers of loess and sand dunes are landscape features
deposited by wind.
• Loess is windblown silt the blankets the landscape.
• Unlike deposits of loess which form blanket-like layers
over broad areas, winds commonly deposit sand in
mound or ridges called dunes.

34. • Badlands occur where weak clays or
shales are exposed to rapid erosion by
running water in semiarid regions.

35. • Types of Sand Dunes
• What form sand dunes assume
depends on the wind direction and
speed, how much sand is available,
and the amount of vegetation.
• Barchan dunes- solitary dunes
chaped like crescent

36. • Wind Erosion
• Wind can be effective agent of erosion anywhere that it is strong
enough to act. Wind can erode by deflation and abrasion.
• Deflation is the lowering of the land surface due to removal of
fine-grained particles by the wind. Deflation concentrates the
coarser grained particles at the surface, eventually resulting in
a surface composed only of the coarser grained fragments
that cannot be transported by the wind. Such a surface is
called desert pavement.

37. • Glacio-fluvial landforms:
• Eskers: Eskars are long, narrow and sinuous of sands
and gravels and are situated in the middle of ground
morains.
• kettle holes
description - This is a small hollow on the landscape.
These are often filled with water (kettle lakes).
• outwash plains
description - These are vast fairly level areas located to
the 'front' of a terminal moraine.
explanation - As a glacier or ice sheet melted (ablated)
then the meltwater carried deposits of gravel, sand ,silt
and clay.

39. • Erosive activity at
different stream
gradient

40. • Floodplain: Floodplains are simply the areas of land that
river floods onto when they exceed bankfull discharge.
Floodplains are created by the constant movement of
meanders. Floodplains tend to be a lot wider in a river's
lower course.