Definition, Nature and Scope of Geomorphology

What is Geomorphology?

Geomorphology is a combination of three words i.e. geo (earth or land) + morphous (shape or form) + logus (study). Combined, this means that geomorphology is the study of different kinds of landforms on the surface of the earth. It also explains the origin of these landforms and rate of change in the shape of these landforms. For example, what are sand dunes, what leads to their formation and what is the rate of change in their height, shape and size etc.? To answer that geomorphologists explain that deposition of sand and small rock particles by the wind leads to formation of sand dunes. The change in height, shape and size of sand dunes depends on direction, speed and consistency of wind. The geomorphologist will also explain why the deserts are located only in certain areas!

Nature of geomorphology

Geomorphology is a multidisciplinary subject where the knowledge of botany, zoology, climatology, glaciology, hydrology, chemistry, physics etc. is used to solve the mystery of landforms’ origin. It tends to provide explanations about the formation of landforms, modifying factors and rate of change in the shape of landforms through hypothesis, theories, principals and laws. Therefore, geomorphology studies the geomorphic phenomenon through scientific methods.

Nature of Sciences

There are two types of sciences i.e. Normative Science and Positive Science.

Normative Science

This type of sciences are based on norms, values, opinions, observation and judgements. The laws formed by normative science will only be fully applicable when those norms, values, opinions etc. are considered true and constant. For example in sociology, an entrepreneur will set up his/her firm at a location which is close to his hometown because he has kinship and emotional relation with his/her hometown. This theory is based on opinion and norms. Such theories might be true in some circumstances and may not be true in others. Normative sciences also explain the solution to problems and tend to change what is not good. Thus, the normative sciences are used highly in public policy. Social sciences are mostly normative science.

Positive Science

Unlike normative science, the laws, principles and theories of positive science are consistent given that their assumptions are fulfilled and other things remain constant. The laws formed by positive sciences are based on facts, data and laws of universal sciences such as physics and chemistry. Therefore, positive sciences explain what is the exact situation on ground. It only aims to study real phenomena and does not concern itself with what ought to be.

For example, the economists consider that the price of any product, say biscuits, increases as the demand for biscuits goes higher and this principle is based on quantitative data regardless of input cost remaining constant. But the laws of positive sciences are not always universal because they are dependent on certain factors remaining constant. For instance, the price of biscuits may rise due to the increase in the price of inputs such as sugar, wheat flour, refined oil etc. even if demand remains the same.

Similarly in geomorphology, it is theorized that water flowing from higher altitude has higher erosion power than water flowing from lower altitude but it is conditioned by the hardness of rock remains the same in both circumstances. This theory is based on quantitative observation and the concept of potential energy. 

Therefore, geomorphology uses the laws of universal sciences, quantitative data, formation of theories etc. for systematic analysis of landforms. Hence, geomorphology is a positive science.

Difference between geology and geomorphology

Geology is a very broad discipline concerned with the study of rocks to unravel earth’s complete history from its birth 4.6 billion years ago (bya) to present times. It is concerned with all the phenomena which are happening and which have stopped happening on the earth surface. Geology tries to unravel a complete set of factors governing earth’s environment during different geologic eras in the past such as climate, plants (flora), animals (fauna), temperature, moisture, sea level etc. Scholars collect the geomorphic information through study of chemical composition, fossils, physical visuals, strength and size of rocks etc.

Geomorphology does not concern itself with such a long period of time. It is only concerned with the formation of landforms which are visible on the surface of earth at present. It also studies the factors governing their formation. Geomorphologists do study the history of earth’s rocks, climate, flora, fauna, temperature, humidity, sea level etc. but only to a limit where these factors explain the existence of present landforms. 

Scope of Geomorphology

Following areas are the main subject matter of geomorphology.

1. Different geomorphic forces carve out different types of landforms i.e. rivers, ocean currents or waves, winds, glaciers, rain, heat and frosting. 
2. These landforms are divided based on scale i.e. First Order, Second Order and Third order.
3. First order landforms include very large scale landforms i.e. continent, oceans basins, plates etc. The second order landforms include plateaus, plains, mountains, deserts etc. The third order landforms include small landforms found within second order landforms, i.e. river valley, delta, oxbow lake.
4. Study of main factors and processes controlling the formation of these landforms. For instance, effect of seasonal and daily temperature change on rock structure etc.
5. Scholars form the theories regulating evolution of landforms under geomorphology e.g. cycle of erosion by Davis.
6. It uses Quantitative methods such as measurement of a geomorphic process and analysis of data to understand trajectory of change. For example, to understand climate change and its impact on glaciers.

Hence, Geomorphology is a very specific field concerned with spatial study of landforms through quantitative and scientific methods. Also Read What is Geography?