Component-I (A)- Personal Detail

Role Name Affiliation Principal Investigator Prof. Masood Ahsan Siddiqui Department of Geography,

Jamia Millia Islamia, New

Delhi

Paper Coordinator Dr.Sayed Zaheen Alam Dyal Singh College, University

of Delhi, New Delhi

Content Writer Dr.Sayed Zaheen Alam Dyal Singh College, University

of Delhi, New Delhi

Content Reviewer Prof. Masood Ahsan Siddiqui Department of Geography,

Jamia Millia Islamia, New

Delhi

Language Editor Prof. Masood Ahsan Siddiqui Department of Geography,

Jamia Millia Islamia, New

Delhi

Component-I (B) Description of Module

Items Description of Module Subject Name Geography

Paper Name Geomorphology

Module Name/Title Nature and Development of Geomorphology

Module Id GEO-1

Pre-requisites Understanding of Fundamnetal concepts of

Geomrophology

Objectives Total Six

Keywords Uniformitarianism, Lithology,Stratigraphy,

Exogenic forces,Differential Erosion,Base

Level,Cycle of Erosion, DGPS, LIDAR,

EDM,Geomorphometry, DEM, DTM and

SWOC

Nature and Development of Geomorphology

Dr.Sayed Zaheen Alam, Assistant Professor, Department of Geography, Dyal Singh College,

University of Delhi, New Delhi.

You may have been interested in Geomorphology, but without knowing it. Probably you have

seen the mountains like Himalayas or the Juhu beach in Mumbai. In these places you may have

noticed that some processes are changing the landscape although with varying intensity. Like for

example in India if you visit from Kanyakumari to Kashmir or Jaisalmer to Arunanchal Pradesh

you will find remarkable variation in the relief features.

Figure: Diversity in the Relief

This may tempt you to question why it is like this? i.e., why there is diversity in the relief

features of the earth’s surface? In the present module we are going to take you on a journey of

science of landscape that is known as Geomorphology, but before that let us see the place of

geomorphology in Geography. We know that ‘Physical Geography’ is the base of geography ‘it

unifies several branches of natural sciences for the purpose of understanding the relationship of

man to his environment’ (Strahler). We can also consider geomorphology as the base of physical

geography. We know that geography is concerned to provide accurate, orderly rational

description of the variable character of the earth’s surface. The focus of geomorphology is also

the‘surface of the earth’.Therefore we can say that it is one of the most important branche of

geography under the banner of physical geography.

In the present module we are going to cover about following aspects of geomorphology:

1. Definition of Geomorphology

2. Organization of the Subject Matter

3. Relationship of Geomorphology with other Subjects

4. Historical Development

4.1 Modern Geomorphology and the Age of Hutton and Lyell in Europe

4.2. Founders of Modern Geomorphology in America

5. Recent Trends in Geomorphology

6. Geomorphology: SWOC analysis

1. Definition of Geomorphology

A geomorphologist attempts to formulate answers to following questions: What is a landform?

What makes one landform unique from another? How are different landforms associated with

each other? Are they arranged in sequential order? How do landforms evolve? How they may

evolve in the future? Likewise what is the significance of geormorphic knowledge for human

society?

The word Geomorphology is derived from three Greek words i.e., Ge (the Earth), Morphe or

Morphi (forms) and Logos (discourse):

Therefore geomorphology represents ‘a discourse on Earth Forms’. In order to understand the

meaning of Geomorphology let us ponder over some basic definitions given by the well known

geomorphologists.

According to Worcester (1949), the “Geomorphology is the interpretative description of the

relief features of the Earth”. The term relief covers the physiography of an area such as

differences in altitude size and shape of the valley, forms and steepness of different slopes.

Therefore geomrphologistsare basically concerned with relief features of the Earth.

According to Bloom (1992) the geomorphology deals with “the systematic description and

analysis of landscapes and the processes that changed them”. Bloom added an important aspect

in the definition of Geomorphology i.e., ‘Processes’ responsible for changing the landscapes. It

should be noted that the nature and intensity of different processes vary from region to region.

These different erosional agents often produce an orderly sequence of landform on the surface

of the Earth. The task of the geomorphologist is to scientifically explore and systematically

arrange the landforms in these orderly sequences. That is why perhaps Thornbury (1993) said

Geomorphology “is the science of Landforms it also includes submarine landforms”. Let ussee

why it is considered as the science of Landforms? We know aim of the science is to explain

what happens in the world. A famous philosopher of Science Hempel suggested that scientific

explanations typically have the logical structure of an argument, i.e. a set of premises followed

by a conclusion. He further said that if the explanation were spelled out in full detail, the law

would enter the picture (S.Okasha 2002). Therefore in general we can say that science beliefs in

observation, reasoning (like inductive and deductive), empirical testing, empirical measurements,

generalizations, systematic study of any phenomenon and the formulation of laws. All these

attributes are also present in geomorphology in one or the other forms. For example, Principle

of Uniformitarianism (Hutton 1785) is a great underlying principle of modern Geomorphology

and Geology. Similarly field observation and measurement is also a part of Geomorphology. For

Example,H. F. Reid of Johns Hopkins University conducted a field study following the great

1906 San Francisco earthquake. On the basis of field observation he proposed ‘Elastic Rebound

Theory’. Likewise,American geomorphologist W.M Davispresented a general theory of

landform development that is popularly known as ‘Cycle of Erosion’. His cycle of erosion was

based on careful field observations. Therefore by nature geomorphology is concerned with

science of landforms.

Did You Know?

The term Geomorphology in modern sense was probably used by Keith in the year1894.

2. Organization of the Subject Matter

In the modern world the raisen d’etre of any discipline is its subject matter and its usefulnessfor

the society. The Subject matter of Geomorphology incorporates Structure, Process, systematic

analysis and evolution of Landforms. Let us discuss in detail about the subject matter of

geomorphology.

(a) The first thing a geomorphologits wants to know is about the terrain i.e.,what is the

structure?

The term structure denotes an arrangement of interrelated elements in a material object or

system. In geomorphology it means (i) Lithology of the rock such as porosity, relative

permeability, folding and faulting; (ii) Stratigraphic arrangement of the rock; (iii) Constitution

or composition of the rock and(iv) Variation in the relief features of the continents and Ocean

basins.The nature and character ofstructures are mainly determined by endogenic or internal

forces. We shall study in detail about these forces in other modules of present paper.

(b) The second term or concept i.e.,process in geomorphology is mainly related to external or

exogenic forces. These forces contribute to shape a landscape. They are also called destructional

processes or denudational processes. A brief list of these endogenic and exogenic processes are

as follows:

It is important to note that geomorphic processes vary in intensity from one region to

another. These variations are mainly attributedto differences in climate, vegetation, and altitude.

The rate of these forces vary from a few centimeters per thousand years for surface weathering of

ancient monuments to 50 meters/second or more for an avalanche (Bloom).

(c) In the systematic analysis of landforms, agemorphologist seeks to classify landforms on the

basis of scale of relief features, genesis and evolution of landforms. It should be noted that one of

the fundamental principles of geomorphology states that “as the different erosional agents act

upon the earth’s surface there is produced an orderly sequence of landforms. Therefore we

can classify landformson in one of the following categories:

(i) Generic Classification of Landforms: Description of entire group or class of landforms i.e.,

Mountain Plateau and Plains. For example Himalayan mountain ranges, Tibetan Plateau and the

Northern plains in India

(ii) Genetic Classification of Landforms: It means classification of landforms by dominant set

of geomorphic processes. For example, Tectonic landforms, fluvial landforms, Karst landforms,

Aeolian landforms, Coastal landforms and Glacial landforms.

(iii) We can also classify the landforms on the basis of their scale and lifespan.

For example the present graph shows the systematic arrangement of landforms on the basis of

their scale and lifespan. On ‘X’ axis the areal coverage of landform is shown in square

kilometers and on ‘Y’ axis average lifespan of each landform is shown in years. For example

average lifespan of “pool” that is a small landform found in the floodplain has a lifespan of

around 10 years on the other hand on top of the graph the ‘major drainage basins’ having almost

entire group of landforms (mainly shaped by river activity) has a lifespan of more than 10

million years. The graph also reveals that the areal coverage of former less is than 0.25 square

kilometer and thecoverage of later is more than 1 million square kilometers.

iv) If we take only scale as the basis for the classification of landforms, we can rearrange the

earth’s landforms into three different orders: for example, Relief Feature of First order, it

includes Continental Platforms and Ocean Basins. Similarly on next level of hierarchy II order

landforms are grouped. The relief features of the second order are superimposed on First order

category of landforms. For example, Plains, Plateau and Mountains. The last order i.e.,III order

relief features are superimposed on II order relief features such as Valleys, Canyons and Dunes.

3. Relationship of Geomorphology with other Subjects

Contemporary geographers classify geomorphology (as a branch of geography) under the Earth

Science Group.

The present figure demonstrates that several other branches of knowledge are directly and

indirectly linked with geomorphology. These allied disciplines are having a kind of mutual

relationship with geomorphology. For example, according to Spark(1960)‘the main contribution

of geomorphology to geology is in unraveling of geographical successions, for example when

deposits are thin and scattered such conditions being most characteristic of Pliocene and

Pleistocene periods in certain areas’. Similarly geomorphologists must have good working

knowledge of geology since without knowing lithology of rock geomorphologist cannot fully

understand the formation and character of landform. One of the fundamental principles of

geomorphology also states that “Geological structure is a dominant control factor in the

evolution of land forms and is reflected in them”. Likewise meteorology provides information

related with effect of climatic elements on the rate and nature of geomorphic processes. In turn

geomorphology contributes to meteorology by disclosing effect of morphology on climatic

variables. For example, the rainfall during the Monsoon season in India is largely affected by the

orographic effect of Himalayas. On the other hand it is equally true that “an appreciation of

world climates is necessary to a proper understanding of the varying importance of the

different geomorphic processes.” (Thornbury, 1993)

4. Historical Development

According to Summerfield (1991) the way geomorphologists approach the study of landforms at

present time can only be seen in proper context if we appreciate how central concepts of

geomorphology have been developed. We can trace the development of Geomorphological ideas

into well marked four periods of history i.e., (i) Ancient Period and Medieval period; (ii) Modern

Geomorphology and the Age of Hutton and Lyell in Europe (iii) Founders of Modern

Geomorphology in America and; (iv) the recent trends

The early writings related with landforms can be traced to the times of early Greek, Roman, Arab

and Chinese thinkers. For example,the father of History Herodotus (484-425 B.C.) once said

“Egypt is the gift of the River (Nile)”. Therefore, he attributed the formation of Nile river delta

to the accumulation of river born silt (Kale and Gupta, 2001). The Aristotle (384-322 B.C.) as

pioneer of inductive reasoning talked about ‘origin of springs’. The Arab civilization during the

medieval period also contributed to the development of geomorphology. Abdullah Ibn Sina

sometimes known in the West by Latin name, Avicenna introduced the concept of “differential

erosion”. He used this term to describe formation of valleys and the altitude of mountains.

According to Thornbury (1993) “a work by a group of unknown Arabic scholars known as ‘The

Discourses of the Brothers of Purity’ (941-982 A.D.)” discussed about erosion and

transportation by streams and wind, weathering and even embryonic idea of pneneplanation.

Thereafter during the renaissance Leonardo da Vinci(1452-1519) discussed about the formation

of valleys by river erosion and presence of marine fossil shells in mountain. The Frenchman

Buffon (1707-1788) also discussed erosive power of stream till sea level.

4.1 Modern Geomorphology and the Age of Hutton and Lyell in Europe

A paper presented by Hutton in the year 1785 before the ‘Royal Society of Edinburgh’ changed

the discourse of the history of Earth’s formation. Hutton proposed that landsurface is evolved by

slow, unremitting erosive power of moving water (Summerfield).He also challenged the

religious viewpoint of a particular faith about the formation of the Earth. Hutton is best known

for his two statements:(i) The present is the key to the past and , (ii) No vestige of a beginning

no prospect of an end. Thus he established the principle or doctrine of Uniformitarianism. His

idea about the ‘Theory of Earth’or formation of earth was more popularised by John Playfair

(1748-1819) and Sir Charles Leyell (1797-1875). Leyelllater became the great follower of

uniformitarianism in Europe.His book ‘Principles of Geology’ was based on Hutton’s principle

of Uniformitarianism.

The discovery of Pleistocene Ice Age by Louis Agassiz (1807-1873) in Europe and the genetic

classification of landscape by Arthur Penk (1894)also created sufficient knowledge base for the

development of physographic geology in Europe. Later Alfred Lothar Wegener in 1912 – a 32

year old lecturer in meteorology and astronomy in Germany propounded the Continental Drift

theory.

Figure: Alfred Lothar Wegener (1880-1930), Propounded Continental Drift theory.

Figure: Pangaea Surrounded by Panthalassa during Upper Carboniferous Period.

This theory was based on sound scientific evidences which ultimately gave birth to the plate

tectonic theory.Todayplate tectonic theory is of a great significance in understanding of the

global distribution of earthquakes, volcanoes and identification of disaster prone areas. We will

also study this theory in detail in a separate module of the present paper.

4.2 Founders of Modern Geomorphology in America

The period between 1875 and 1900 are considered as “the heroic age in American

geomorphology” (Thornbury, 1993). The champions of this period were Major J.W.Powell

(1834-1902), G.Gilbert (1843-1918) and the C.E. Dutton (1841-1912).

Powell is known for the concept of ‘base level’ i.e., a level below which the dry lands cannot be

eroded. The present laws of landscape development are built around Gilbert’s dynamic

equilibrium mechanism. Gilbert also attempted to develop quantitative approachin

geomorphology. The purpose of his quantitative approach was to explainthe relationship between

stream load, volume and velocity of water vis a vis gradient factor. Dutton applied the concept

of ‘base level’ to analyse the ‘Great Denudation’ in Colorado Plateaus area in United Sates of

America. W.M. Davis (1850-1934) associated with Harvard University quickly grasped the idea

of ‘base level’ given by Powell, great denudation discovered by Dutton and the quantitative

approach proposed by Gilbert. On the basis of their ideas Davis proposed the ‘cycle of erosion’.

He described the evolution oflandforms in terms of structure, process and time.

It should be noted that W.M. Davis theory was extremely popular in geomorphology for a

long time, but it was ultimately superseded by new datasets and the development of plate

tectonic theory (Goudie and Viles, 2010). We shall study geomorphic cycle and plate tectonic

theory in separate modules of present paper.

5. Recent Trends in Geomorphology

The present day geomorphologists are largely influenced by two important revolutions occurred

in the discipline of Geography i.e., ‘Quantitative revolution’ and the ‘Process revolution’. The

former introduced explicit emphasis on the use of scientific methods and later developed the

greater understanding of the processes responsible for the creation of variable character of the

earth surface.

The measurement, monitoring, analysis and modelling of the formative processes have become

integral part of present day geomorphology. For example, Differential GPS (or DGPS) is now

commonly used by geomorphologists to identify precise location of topographical features. This

prices measurement is also extremely useful for the changes happening in the glacier areas

especially to monitor climate change. It is equally helpful for the identification of hazards

related with landslides and slope failures. The Ground based Light Detection and Ranging

(LIDAR) is another instrument to identify precise location of third order landforms especially in

inaccessible areas of the earth. The modern day sensitive instruments can even track the relative

movement of different plates, glaciers as well as lava flow in a volcanic region.

The high resolution satellite imageries, Computer aided Cartography, Electronic Distance

Measurement (EDM), Global Positioning System (GPS) and GIS softwares haveimmensely

contributed to the development of a new specialized branch of geomorphology i.e.,

Geomorphometry.

Now within a fraction of a second gemorphologists can compute topographic elements through

Digital Elevation Models (DEMs) and Digital Terrain Models (DTMs).

The freely available Google Earth satellite imageries have given new tool to explore the

inaccessible parts of the world. Now a volcanologist can virtually explore an active volcano

through the near real time satellite imageries. For example the present imagery is showing an

areal view of a crater at the summit of Mt St. Helens (USA).This image has been taken by

satellite.

Figure: Areal view of a crater at the summit of Mt St. Helens (USA). Image credit: ©Google

earth 2015).

A wealth of data on the quantities of sediments found in the deep sea basins of the planet earth

by ‘Integrated Ocean drilling project’ has lured several young researchers to go deep into the

field of geomorphology or specifically oceanography. The drilling projects have also contributed

to applied geomorphology. For example identification of oil exploration sites require application

of geomorphic knowledge. The use of geomorphic knowledge to find answers to the problems

faced by human beings is called ‘applied geomorphology’. For example geomorphicknowledge

is prerequisitefor managing and preventing natural hazards, land resource planning,

Environmental Impact Assessment, site suitability analysis for House, Industry and dams.It

is more advantageous that we know, for instance, something of the discharge and sediment load

of streams, than they are ‘young’ or ‘mature’, as Davis described them (Bryant, 1992). We will

also attempt to discuss applied geomorphology in separate module of this paper. At present with

the advent of the internet and improved access to many sources, the research literature in

geomorphology has increased rapidly. In 2013 alone, the Journal of Geomorphology published

369 research papers, most of a highly technical nature (Gregory and Lewin, 2014).

6. The State of Geomorphology: SWOC analysis:

Let us see the state of geomorphology through SWOC analysis i.e., Strength, Weaknesses,

opportunities and challenges:

Geomorphology: Strength and Opportunities

Geomorphology is enriched with well developed fundamental concepts. There is no dearth of

books related to geomorphology.

(b) Geomorphology is scientific in nature. The techniques like EDM, GPS and GIS, Numerical

Analysis and Laboratory analysis of rocks and sediments, and several instruments used in filed

investigations makes scientific identity of the discipline.

(c) Several developments in the field of science and technology has opened many specialized

branches of geomorphology such as, remote-sensing geomorphology, experimental

geomorphology, extraterrestrial (planetary) geomorphology, engineering geomorphology and

anthropogenic-geomorphology. One can also become an expert in these branches. For example,

Fluvial Geomorphologist,Karst Geomorphologists, Coastal Geomorphologists,

Biogeomorphologist, Tropical Geomorphologist, Mountain Geomorphologist. The applied

geomorphology also offers many job opportunities in specialized fields. For example,expert in

disaster management, EIA expert and Environmental Specialist.

Geomorphology: Weaknesses and Challenges

Geomorphology requires a rigorous understanding of the fundamentals concepts of the

discipline. It is basically a heterogeneous science; therefore it requires expertise in various filed

of sciences. The instruments required for geomorphometric analysis are very costly. Therefore,

the field work is very expensive. Thisbranch of physical geography hasalso not captured the

interest of general public except in case of random news events related to volcanic eruptions

and earthquakes. Recent massive 7.9 magnitude shallow focus Nepalearthquake on 25, April,

2015 at 11.48 AM (IST) hasshocked the world. It claimed the life of more than 9,000 people in

our neighboring country Nepal, which is one of the worst in Nepal’s history. Nepal is still coping

with the aftermath of the earthquake. Therefore geomorphic literacy is extremely important not

only to understand the phenomena but also for disaster. We will also study in detail about the

earthquakes and geomorphic hazards in different modules of present paper.

Thank you