Geomorphology

Geomorphology

Overview
Geomorphology is the scientific study of landform
Landform
A landform or physical feature in the earth sciences and geology sub-fields, comprises a geomorphological unit, and is largely defined by its surface form and location in the landscape, as part of the terrain, and as such, is typically an element of topography...

s and the processes that shape them. Geomorphologists seek to understand why landscape
Landscape
Landscape comprises the visible features of an area of land, including the physical elements of landforms such as mountains, hills, water bodies such as rivers, lakes, ponds and the sea, living elements of land cover including indigenous vegetation, human elements including different forms of...

s look the way they do, to understand landform history and dynamics, and to predict future changes through a combination of field observations, physical experiments, and numerical modeling
Landscape evolution model
A landscape evolution model is a physically based numerical model that simulates changing terrain over the course of time. This can be due to glacial erosion and deposition; erosion, sediment transport, and deposition in fluvial systems such as rivers; regolith production; the movement of material...

. Geomorphology is practiced within geography
Geography
Geography is the science that studies the lands, features, inhabitants, and phenomena of Earth. A literal translation would be "to describe or write about the Earth". The first person to use the word "geography" was Eratosthenes...

, geology
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...

, geodesy
Geodesy
Geodesy , also named geodetics, a branch of earth sciences, is the scientific discipline that deals with the measurement and representation of the Earth, including its gravitational field, in a three-dimensional time-varying space. Geodesists also study geodynamical phenomena such as crustal...

, engineering geology
Engineering geology
Engineering geology is the application of the geologic sciences to engineering practice for the purpose of assuring that the geologic factors affecting the location, design, construction, operation and maintenance of engineering works are recognized and adequately provided for...

, archaeology
Archaeology
Archaeology, or archeology , is the study of human society, primarily through the recovery and analysis of the material culture and environmental data that they have left behind, which includes artifacts, architecture, biofacts and cultural landscapes...

, and geotechnical engineering
Geotechnical engineering
Geotechnical engineering is the branch of civil engineering concerned with the engineering behavior of earth materials. Geotechnical engineering is important in civil engineering, but is also used by military, mining, petroleum, or any other engineering concerned with construction on or in the ground...

, and this broad base of interest contributes to a wide variety of research styles and interests within the field.

The surface of Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

 is modified by a combination of surface processes that sculpt landscapes, and geologic processes that cause tectonic uplift
Tectonic uplift
Tectonic uplift is a geological process most often caused by plate tectonics which increases elevation. The opposite of uplift is subsidence, which results in a decrease in elevation. Uplift may be orogenic or isostatic.-Orogenic uplift:...

 and subsidence
Subsidence
Subsidence is the motion of a surface as it shifts downward relative to a datum such as sea-level. The opposite of subsidence is uplift, which results in an increase in elevation...

.
Discussion
Ask a question about 'Geomorphology'
Start a new discussion about 'Geomorphology'
Answer questions from other users
Full Discussion Forum
 
Unanswered Questions
Recent Discussions
Encyclopedia
Geomorphology is the scientific study of landform
Landform
A landform or physical feature in the earth sciences and geology sub-fields, comprises a geomorphological unit, and is largely defined by its surface form and location in the landscape, as part of the terrain, and as such, is typically an element of topography...

s and the processes that shape them. Geomorphologists seek to understand why landscape
Landscape
Landscape comprises the visible features of an area of land, including the physical elements of landforms such as mountains, hills, water bodies such as rivers, lakes, ponds and the sea, living elements of land cover including indigenous vegetation, human elements including different forms of...

s look the way they do, to understand landform history and dynamics, and to predict future changes through a combination of field observations, physical experiments, and numerical modeling
Landscape evolution model
A landscape evolution model is a physically based numerical model that simulates changing terrain over the course of time. This can be due to glacial erosion and deposition; erosion, sediment transport, and deposition in fluvial systems such as rivers; regolith production; the movement of material...

. Geomorphology is practiced within geography
Geography
Geography is the science that studies the lands, features, inhabitants, and phenomena of Earth. A literal translation would be "to describe or write about the Earth". The first person to use the word "geography" was Eratosthenes...

, geology
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...

, geodesy
Geodesy
Geodesy , also named geodetics, a branch of earth sciences, is the scientific discipline that deals with the measurement and representation of the Earth, including its gravitational field, in a three-dimensional time-varying space. Geodesists also study geodynamical phenomena such as crustal...

, engineering geology
Engineering geology
Engineering geology is the application of the geologic sciences to engineering practice for the purpose of assuring that the geologic factors affecting the location, design, construction, operation and maintenance of engineering works are recognized and adequately provided for...

, archaeology
Archaeology
Archaeology, or archeology , is the study of human society, primarily through the recovery and analysis of the material culture and environmental data that they have left behind, which includes artifacts, architecture, biofacts and cultural landscapes...

, and geotechnical engineering
Geotechnical engineering
Geotechnical engineering is the branch of civil engineering concerned with the engineering behavior of earth materials. Geotechnical engineering is important in civil engineering, but is also used by military, mining, petroleum, or any other engineering concerned with construction on or in the ground...

, and this broad base of interest contributes to a wide variety of research styles and interests within the field.

Overview


The surface of Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

 is modified by a combination of surface processes that sculpt landscapes, and geologic processes that cause tectonic uplift
Tectonic uplift
Tectonic uplift is a geological process most often caused by plate tectonics which increases elevation. The opposite of uplift is subsidence, which results in a decrease in elevation. Uplift may be orogenic or isostatic.-Orogenic uplift:...

 and subsidence
Subsidence
Subsidence is the motion of a surface as it shifts downward relative to a datum such as sea-level. The opposite of subsidence is uplift, which results in an increase in elevation...

. Surface processes comprise the action of water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

, wind
Wind
Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...

, ice
Ice
Ice is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...

, fire
Wildfire
A wildfire is any uncontrolled fire in combustible vegetation that occurs in the countryside or a wilderness area. Other names such as brush fire, bushfire, forest fire, desert fire, grass fire, hill fire, squirrel fire, vegetation fire, veldfire, and wilkjjofire may be used to describe the same...

, and living things on the surface of the Earth, along with chemical reactions that form soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

s and alter material properties, the stability and rate of change of topography under the force of gravity, and other factors, such as (in the very recent past) human alteration of the landscape. Many of these factors are strongly mediated by climate
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...

. Geologic processes include the uplift of mountain range
Mountain range
A mountain range is a single, large mass consisting of a succession of mountains or narrowly spaced mountain ridges, with or without peaks, closely related in position, direction, formation, and age; a component part of a mountain system or of a mountain chain...

s, the growth of volcanoes, isostatic
Isostasy
Isostasy is a term used in geology to refer to the state of gravitational equilibrium between the earth's lithosphere and asthenosphere such that the tectonic plates "float" at an elevation which depends on their thickness and density. This concept is invoked to explain how different topographic...

 changes in land surface elevation (sometimes in response to surface processes), and the formation of deep sedimentary basins where the surface of Earth drops and is filled with material eroded from other parts of the landscape. The Earth surface and its topography therefore are an intersection of climatic, hydrologic
Hydrology
Hydrology is the study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability...

, and biologic
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...

 action with geologic processes.

The broad-scale topographies of Earth illustrate this intersection of surface and subsurface action. Mountain belts are uplifted
Tectonic uplift
Tectonic uplift is a geological process most often caused by plate tectonics which increases elevation. The opposite of uplift is subsidence, which results in a decrease in elevation. Uplift may be orogenic or isostatic.-Orogenic uplift:...

 due to geologic processes. Denudation
Denudation
In geology, denudation is the long-term sum of processes that cause the wearing away of the earth’s surface leading to a reduction in elevation and relief of landforms and landscapes...

 of these high uplifted regions produces sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....

 that is transported and deposited
Deposition (geology)
Deposition is the geological process by which material is added to a landform or land mass. Fluids such as wind and water, as well as sediment flowing via gravity, transport previously eroded sediment, which, at the loss of enough kinetic energy in the fluid, is deposited, building up layers of...

 elsewhere within the landscape or off the coast. On progressively smaller scales, similar ideas apply, where individual landforms evolve in response to the balance of additive processes (uplift and deposition) and subtractive processes (subsidence
Subsidence
Subsidence is the motion of a surface as it shifts downward relative to a datum such as sea-level. The opposite of subsidence is uplift, which results in an increase in elevation...

 and erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

). Often, these processes directly affect each other: ice sheets, water, and sediment are all loads that change topography through flexural isostasy. Topography can modify the local climate, for example through orographic precipitation, which in turn modifies the topography by changing the hydrologic regime in which it evolves. Many geomorphologists are particularly interested in the potential for feedbacks between climate and tectonics
Erosion and tectonics
The interplay between erosion and tectonics has been a matter of debate since the early 1990s. While tectonic effects on surface processes such as erosion have been long recognized, the reverse has only recently been addressed thanks to the availability of computer...

 mediated by geomorphic processes.

In addition to these broad-scale questions, geomorphologists address issues that are more specific and/or more local. Glacial geomorphologists investigate glacial deposits such as moraine
Moraine
A moraine is any glacially formed accumulation of unconsolidated glacial debris which can occur in currently glaciated and formerly glaciated regions, such as those areas acted upon by a past glacial maximum. This debris may have been plucked off a valley floor as a glacier advanced or it may have...

s, esker
Esker
An esker is a long winding ridge of stratified sand and gravel, examples of which occur in glaciated and formerly glaciated regions of Europe and North America...

s, and proglacial lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

s, as well as glacial erosional features, to build chronologies of both small glacier
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

s and large ice sheet
Ice sheet
An ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 km² , thus also known as continental glacier...

s and understand their motions and effects upon the landscape. Fluvial
Fluvial
Fluvial is used in geography and Earth science to refer to the processes associated with rivers and streams and the deposits and landforms created by them...

 geomorphologists focus on river
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

s, how they transport sediment
Sediment transport
Sediment transport is the movement of solid particles , typically due to a combination of the force of gravity acting on the sediment, and/or the movement of the fluid in which the sediment is entrained...

, migrate across the landscape
River channel migration
River channel migration is the lateral motion of an alluvial river channel across its floodplain due to processes of erosion of and deposition on its banks and bars. In meandering streams, channel migration typically takes place by erosion of the cut bank and deposition on the point bar...

, cut into bedrock
Bedrock river
A bedrock river is a river that typically has little to no alluvium mantling the bedrock over which it flows. Such rivers are common in upland and mountainous regions...

, respond to environmental and tectonic changes, and interact with humans. Soils geomorphologists investigate soil profiles and chemistry to learn about the history of a particular landscape and understand how climate, biota, and rock interact. Other geomorphologists study how hill
Hill
A hill is a landform that extends above the surrounding terrain. Hills often have a distinct summit, although in areas with scarp/dip topography a hill may refer to a particular section of flat terrain without a massive summit A hill is a landform that extends above the surrounding terrain. Hills...

slopes form and change. Still others investigate the relationships between ecology
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...

 and geomorphology. Because geomorphology is defined to comprise everything related to the surface of Earth and its modification, it is a broad field with many facets.

Practical applications of geomorphology include hazard
Natural hazard
A natural hazard is a threat of a naturally occurring event that will have a negative effect on people or the environment. Many natural hazards are interrelated, e.g. earthquakes can cause tsunamis and drought can lead directly to famine. It is possible that some natural hazards are...

 assessment (such as landslide
Landslide
A landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rockfalls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments...

 prediction and mitigation), river control and stream restoration
Stream restoration
Stream restoration or river restoration, sometimes called river reclamation in the UK, describes a set of activities that help improve the environmental health of a river or stream. Improved health may be indicated by expanded habitat for diverse species and reduced stream bank erosion...

, and coastal protection.

History


With some notable exceptions (see below), geomorphology is a relatively young science, growing along with interest in other aspects of the earth sciences in the mid-19th century. This section provides a very brief outline of some of the major figures and events in its development.

Ancient geomorphology


Perhaps the earliest one to devise a theory of geomorphology was the polymath Chinese
History of China
Chinese civilization originated in various regional centers along both the Yellow River and the Yangtze River valleys in the Neolithic era, but the Yellow River is said to be the Cradle of Chinese Civilization. With thousands of years of continuous history, China is one of the world's oldest...

 scientist and statesman Shen Kuo
Shen Kuo
Shen Kuo or Shen Gua , style name Cunzhong and pseudonym Mengqi Weng , was a polymathic Chinese scientist and statesman of the Song Dynasty...

 (1031-1095 AD). This was based on his observation of marine
Ocean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...

 fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

 shells in a geological stratum
Stratum
In geology and related fields, a stratum is a layer of sedimentary rock or soil with internally consistent characteristics that distinguish it from other layers...

 of a mountain hundreds of miles from the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

. Noticing bivalve
Bivalvia
Bivalvia is a taxonomic class of marine and freshwater molluscs. This class includes clams, oysters, mussels, scallops, and many other families of molluscs that have two hinged shells...

 shells running in a horizontal span along the cut section of a cliffside, he theorized that the cliff was once the pre-historic location of a seashore that had shifted hundreds of miles over the centuries. He inferred that the land was reshaped and formed by soil erosion of the mountains and by deposition of silt
Silt
Silt is granular material of a size somewhere between sand and clay whose mineral origin is quartz and feldspar. Silt may occur as a soil or as suspended sediment in a surface water body...

, after observing strange natural erosions of the Taihang Mountains
Taihang Mountains
The Taihang Mountains are a Chinese mountain range running down the eastern edge of the Loess Plateau in Henan, Shanxi and Hebei provinces. The range extends over 400 km from north to south and has an average elevation of 1,500 to 2,000 meters. The principal peak is Xiao Wutaishan...

 and the Yandang Mountain near Wenzhou
Wenzhou
Wenzhou is a prefecture-level city in southeastern Zhejiang province, People's Republic of China. The area under its jurisdiction, which includes two satellite cities and six counties, had a population of 9,122,100 as of 2010....

. Furthermore, he promoted the theory of gradual climate change
Climate change
Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...

 over centuries of time once ancient petrified bamboo
Bamboo
Bamboo is a group of perennial evergreens in the true grass family Poaceae, subfamily Bambusoideae, tribe Bambuseae. Giant bamboos are the largest members of the grass family....

s were found to be preserved underground in the dry, northern climate zone of Yanzhou, which is now modern day Yan'an
Yan'an
Yan'an , is a prefecture-level city in the Shanbei region of Shaanxi province in China, administering several counties, including Zhidan County , which served as the Chinese communist capital before the city of Yan'an proper took that role....

, Shaanxi
Shaanxi
' is a province in the central part of Mainland China, and it includes portions of the Loess Plateau on the middle reaches of the Yellow River in addition to the Qinling Mountains across the southern part of this province...

 province.

Early modern geomorphology


The first use of the word geomorphology was likely to be in the German language
German language
German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....

 when it appeared in Laumann's 1858 work. Keith Tinkler has suggested that the word came into general use in English, German and French after John Wesley Powell
John Wesley Powell
John Wesley Powell was a U.S. soldier, geologist, explorer of the American West, and director of major scientific and cultural institutions...

 and W. J. McGee used it in the International Geological Conference of 1891.

An early popular geomorphic model was the geographical cycle or the cycle of erosion
Cycle of erosion
The cycle of erosion was a model for stream erosion and landscape development proposed by William Morris Davis in the late 19th century. Davis' Stages in the fluvial cycle of erosion published in 1909 defined a young, mature, and old sequence in the development of river valleys and the landscape...

, developed by William Morris Davis
William Morris Davis
William Morris Davis was an American geographer, geologist, geomorphologist, and meteorologist, often called the "father of American geography"....

 between 1884 and 1899. The cycle was inspired by theories of uniformitarianism
Uniformitarianism (science)
In the philosophy of naturalism, the uniformitarianism assumption is that the same natural laws and processes that operate in the universe now, have always operated in the universe in the past and apply everywhere in the universe. It has included the gradualistic concept that "the present is the...

 first formulated by James Hutton
James Hutton
James Hutton was a Scottish physician, geologist, naturalist, chemical manufacturer and experimental agriculturalist. He is considered the father of modern geology...

 (1726–1797). Concerning valley
Valley
In geology, a valley or dale is a depression with predominant extent in one direction. A very deep river valley may be called a canyon or gorge.The terms U-shaped and V-shaped are descriptive terms of geography to characterize the form of valleys...

 forms, uniformitarianism depicted the cycle as a sequence in which a river cuts a valley more and more deeply, but then erosion of side valley
Side valley
The terms side valley and tributary valley refer to valleys whose brook or river is confluent to a greater one.Upstream, the valleys can be classified in an increasing order which is equivalent to the usual orographic order: the tributaries are ordered from those nearest to the source of the river...

s eventually flatten the terrain again, to a lower elevation. Tectonic uplift
Tectonic uplift
Tectonic uplift is a geological process most often caused by plate tectonics which increases elevation. The opposite of uplift is subsidence, which results in a decrease in elevation. Uplift may be orogenic or isostatic.-Orogenic uplift:...

 could start the cycle over. Many studies in geomorphology in the decades following Davis' development of his theories sought to fit their ideas into this framework for broad scale landscape evolution, and are often today termed "Davisian". Davis' ideas have largely been superseded today, mainly due to their lack of predictive power and qualitative nature, but he remains an extremely important figure in the history of the subject.

In the 1920s, Walther Penck
Walther Penck
Walther Penck was an Austrian geographer, born in Vienna as son of geographer Albrecht Penck.Walther Penck worked 1912-1914 in Argentina as a geographer, and is best known for his contributions to the field of geomorphology...

 developed an alternative model to Davis', believing that landform evolution was better described as a balance between ongoing processes of uplift and denudation, rather than Davis' single uplift followed by decay. However, due to his relatively young death, disputes with Davis and a lack of English translation of his work his ideas were not widely recognised for many years.

These authors were both attempting to place the study of the evolution of the Earth's surface on a more generalized, globally relevant footing than had existed before. In the earlier parts of the 19th century, authors - especially in Europe - had tended to attribute the form of landscape to local climate
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...

, and in particular to the specific effects of glaciation and periglacial
Periglacial
Periglacial is an adjective originally referring to places in the edges of glacial areas, but it has later been widely used in geomorphology to describe any place where geomorphic processes related to freezing of water occur...

 processes. In contrast, both Davis and Penck were seeking to emphasize the importance of evolution of landscapes through time and the generality of Earth surface processes across different landscapes under different conditions.

Quantitative geomorphology


While Penck and Davis and their followers were writing and studying primarily in Western Europe
Western Europe
Western Europe is a loose term for the collection of countries in the western most region of the European continents, though this definition is context-dependent and carries cultural and political connotations. One definition describes Western Europe as a geographic entity—the region lying in the...

, another, largely separate, school of geomorphology was developed in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 in the middle years of the 20th century. Following the early trailblazing work of Grove Karl Gilbert
Grove Karl Gilbert
Grove Karl Gilbert , known by the abbreviated name G. K. Gilbert in academic literature, was an American geologist....

 around the turn of the 20th century, a group of natural scientists, geologists and hydraulic engineers including Ralph Alger Bagnold
Ralph Alger Bagnold
Brigadier Ralph Alger Bagnold, FRS OBE, was the founder and first commander of the British Army's Long Range Desert Group during World War II. He is also generally considered to have been a pioneer of desert exploration, an acclaim earned for his activities during the 1930s...

, John Hack, Luna Leopold
Luna Leopold
Luna Bergere Leopold was a leading U.S. geomorphologist and hydrologist, and son of Aldo Leopold. He received a B.S. in Civil Engineering from the University of Wisconsin, Madison in 1936; an M.S. in Physics-Meteorology from the University of California, Los Angeles in 1944; and a Ph.D...

, Thomas Maddock and Arthur Strahler began to research the form of landscape elements such as rivers and hillslopes
Mass wasting
Mass wasting, also known as slope movement or mass movement, is the geomorphic process by which soil, regolith, and rock move downslope under the force of gravity. Types of mass wasting include creep, slides, flows, topples, and falls, each with its own characteristic features, and taking place...

 by taking systematic, direct, quantitative measurements of aspects of them and investigating the scaling of these measurements. These methods began to allow prediction of the past and future behavior of landscapes from present observations, and were later to develop into what the modern trend of a highly quantitative approach to geomorphic problems. Quantitative geomorphology can involve fluid dynamics
Fluid dynamics
In physics, fluid dynamics is a sub-discipline of fluid mechanics that deals with fluid flow—the natural science of fluids in motion. It has several subdisciplines itself, including aerodynamics and hydrodynamics...

 and solid mechanics
Solid mechanics
Solid mechanics is the branch of mechanics, physics, and mathematics that concerns the behavior of solid matter under external actions . It is part of a broader study known as continuum mechanics. One of the most common practical applications of solid mechanics is the Euler-Bernoulli beam equation...

, geomorphometry
Geomorphometry
Geomorphometry is the science of quantitative land surface analysis. It gathers various mathematical, statistical and image processing techniques that can be used to quantify morphological, hydrological, ecological and other aspects of a land surface. Common synonyms for geomorphometry are...

, laboratory studies, field measurements, theoretical work, and full landscape evolution model
Landscape evolution model
A landscape evolution model is a physically based numerical model that simulates changing terrain over the course of time. This can be due to glacial erosion and deposition; erosion, sediment transport, and deposition in fluvial systems such as rivers; regolith production; the movement of material...

ing. These approaches are used to understand weathering
Weathering
Weathering is the breaking down of rocks, soils and minerals as well as artificial materials through contact with the Earth's atmosphere, biota and waters...

 and the formation of soils
Pedogenesis
Pedogenesis is the science and study of the processes that lead to the formation of soil ' and first explored by the Russian geologist Vasily Dokuchaev , the so called grandfather of soil science, who determined that soil formed over time as a consequence of...

, sediment transport
Sediment transport
Sediment transport is the movement of solid particles , typically due to a combination of the force of gravity acting on the sediment, and/or the movement of the fluid in which the sediment is entrained...

, landscape change, and the interactions between climate, tectonics, erosion, and deposition.

Contemporary geomorphology


Today, the field of geomorphology encompasses a very wide range of different approaches and interests. Modern researchers aim to draw out quantitative "laws" that govern Earth surface processes, but equally, recognize the uniqueness of each landscape and environment in which these processes operate. Particularly important realizations in contemporary geomorphology include:

1) that not all landscapes can be considered as either "stable" or "perturbed", where this perturbed state is a temporary displacement away from some ideal target form. Instead, dynamic changes of the landscape are now seen as an essential part of their nature.

2) that many geomorphic systems are best understood in terms of the stochasticity
Stochastic process
In probability theory, a stochastic process , or sometimes random process, is the counterpart to a deterministic process...

 of the processes occurring in them, that is, the probability distributions of event magnitudes and return times. This in turn has indicated the importance of chaotic determinism
Chaos theory
Chaos theory is a field of study in mathematics, with applications in several disciplines including physics, economics, biology, and philosophy. Chaos theory studies the behavior of dynamical systems that are highly sensitive to initial conditions, an effect which is popularly referred to as the...

 to landscapes, and that landscape properties are best considered statistically
Statistics
Statistics is the study of the collection, organization, analysis, and interpretation of data. It deals with all aspects of this, including the planning of data collection in terms of the design of surveys and experiments....

. The same processes in the same landscapes does not always lead to the same end results.

Processes



Modern geomorphology focuses on the quantitative analysis of interconnected processes. Modern advances in geochronology
Geochronology
Geochronology is the science of determining the age of rocks, fossils, and sediments, within a certain degree of uncertainty inherent to the method used. A variety of dating methods are used by geologists to achieve this, and schemes of classification and terminology have been proposed...

, in particular cosmogenic radionuclide dating, optically stimulated luminescence dating and low-temperature thermochronology
Thermochronology
Thermochronology is the study of the thermal evolution of a region of a planet. Thermochronologists use radiometric dating along with the closure temperatures that represent the temperature of the mineral being studied at the time given by the date recorded, to understand the thermal history of a...

 have enabled us for the first time to measure the rates at which geomorphic processes occur. At the same time, the use of more precise physical measurement techniques, including differential GPS
Differential GPS
Differential Global Positioning System is an enhancement to Global Positioning System that provides improved location accuracy, from the 15-meter nominal GPS accuracy to about 10 cm in case of the best implementations....

, remotely sensed digital terrain models and laser scanning techniques, have allowed quantification and study of these processes as they happen. Computer simulation
Simulation
Simulation is the imitation of some real thing available, state of affairs, or process. The act of simulating something generally entails representing certain key characteristics or behaviours of a selected physical or abstract system....

 and modeling may then be used to test our understanding of how these processes work together and through time.

Geomorphically relevant processes generally fall into (1) the production of regolith
Regolith
Regolith is a layer of loose, heterogeneous material covering solid rock. It includes dust, soil, broken rock, and other related materials and is present on Earth, the Moon, some asteroids, and other terrestrial planets and moons.-Etymology:...

 by weathering
Weathering
Weathering is the breaking down of rocks, soils and minerals as well as artificial materials through contact with the Earth's atmosphere, biota and waters...

 and erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

, the transport
Sediment transport
Sediment transport is the movement of solid particles , typically due to a combination of the force of gravity acting on the sediment, and/or the movement of the fluid in which the sediment is entrained...

 of that material, and its eventual deposition
Deposition (geology)
Deposition is the geological process by which material is added to a landform or land mass. Fluids such as wind and water, as well as sediment flowing via gravity, transport previously eroded sediment, which, at the loss of enough kinetic energy in the fluid, is deposited, building up layers of...

. Although there is a general movement of material from uplands to lowlands, erosion, transport, and deposition often occur in closely spaced tandem all across the landscape.

The nature of the processes investigated by geomorphologists is strongly dependent on the landscape or landform under investigation and the time and length scales of interest. However, the following non-exhaustive list provides a flavor of the landscape elements associated with some of these.

Primary surface processes responsible for most topographic features include wind
Wind
Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...

, wave
Wave
In physics, a wave is a disturbance that travels through space and time, accompanied by the transfer of energy.Waves travel and the wave motion transfers energy from one point to another, often with no permanent displacement of the particles of the medium—that is, with little or no associated mass...

s, chemical dissolution
Weathering
Weathering is the breaking down of rocks, soils and minerals as well as artificial materials through contact with the Earth's atmosphere, biota and waters...

, mass wasting
Mass wasting
Mass wasting, also known as slope movement or mass movement, is the geomorphic process by which soil, regolith, and rock move downslope under the force of gravity. Types of mass wasting include creep, slides, flows, topples, and falls, each with its own characteristic features, and taking place...

, groundwater
Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...

 movement, surface water
Surface water
Surface water is water collecting on the ground or in a stream, river, lake, wetland, or ocean; it is related to water collecting as groundwater or atmospheric water....

 flow, glacial action
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

, tectonism, and volcanism
Volcanism
Volcanism is the phenomenon connected with volcanoes and volcanic activity. It includes all phenomena resulting from and causing magma within the crust or mantle of a planet to rise through the crust and form volcanic rocks on the surface....

. Other more exotic geomorphic processes might include periglacial
Periglacial
Periglacial is an adjective originally referring to places in the edges of glacial areas, but it has later been widely used in geomorphology to describe any place where geomorphic processes related to freezing of water occur...

 (freeze-thaw) processes, salt-mediated action, or extraterrestrial impact.

Fluvial processes




Rivers and streams are not only conduits of water, but also of sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....

. The water, as it flows over the channel bed, is able to mobilize sediment and transport it downstream, either as bed load
Bed load
The term bed load or bedload describes particles in a flowing fluid that are transported along the bed. Bed load is complementary to suspended load and wash load.Bed load moves by rolling, sliding, and/or saltating ....

, suspended load
Suspended load
Suspended load is the portion of the sediment that is carried by a fluid flow which settle slowly enough such that it almost never touches the bed...

 or dissolved load
Dissolved load
Dissolved load is the term for material, especially ions from chemical weathering, that are carried in solution by a stream. The dissolved load contributes to the total amount of material removed from a catchment. The amount of material carried as dissolved load is typically much smaller than the...

. The rate of sediment transport depends on the availability of sediment itself and on the river's discharge
Discharge (hydrology)
In hydrology, discharge is the volume rate of water flow, including any suspended solids , dissolved chemical species and/or biologic material , which is transported through a given cross-sectional area...

.

Rivers are also capable of eroding into rock and creating new sediment, both from their own beds and also by coupling to the surrounding hillslopes. In this way, rivers are thought of as setting the base level for large scale landscape evolution in nonglacial environments. Rivers are key links in the connectivity of different landscape elements.

As rivers flow across the landscape, they generally increase in size, merging with other rivers. The network of rivers thus formed is a drainage system
Drainage system (Geomorphology)
In geomorphology, a drainage system is the pattern formed by the streams, rivers, and lakes in a particular drainage basin. They are governed by the topography of the land, whether a particular region is dominated by hard or soft rocks, and the gradient of the land. Geomorphologists and...

 and is often dendritic, but may adopt other patterns depending on the regional topography and underlying geology.

Aeolian processes



Aeolian processes pertain to the activity of the wind
Wind
Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...

s and more specifically, to the winds' ability to shape the surface of the Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

. Winds may erode, transport, and deposit materials, and are effective agents in regions with sparse vegetation
Vegetation
Vegetation is a general term for the plant life of a region; it refers to the ground cover provided by plants. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characteristics. It is broader...

 and a large supply of unconsolidated sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....

s. Although water and mass flow tend to mobilize more material than wind in most environments, aeolian processes are important in arid environments such as desert
Desert
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...

s.

Hillslope processes



Soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

, regolith
Regolith
Regolith is a layer of loose, heterogeneous material covering solid rock. It includes dust, soil, broken rock, and other related materials and is present on Earth, the Moon, some asteroids, and other terrestrial planets and moons.-Etymology:...

, and rock
Rock (geology)
In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...

 move downslope under the force of gravity via creep, slides, flows, topples, and falls. Such mass wasting
Mass wasting
Mass wasting, also known as slope movement or mass movement, is the geomorphic process by which soil, regolith, and rock move downslope under the force of gravity. Types of mass wasting include creep, slides, flows, topples, and falls, each with its own characteristic features, and taking place...

 occurs on both terrestrial and submarine slopes, and has been observed on Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

, Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

, Venus
Venus
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows...

, Titan
Titan (moon)
Titan , or Saturn VI, is the largest moon of Saturn, the only natural satellite known to have a dense atmosphere, and the only object other than Earth for which clear evidence of stable bodies of surface liquid has been found....

 and Iapetus
Iapetus (moon)
Iapetus ), occasionally Japetus , is the third-largest moon of Saturn, and eleventh in the Solar System. It was discovered by Giovanni Domenico Cassini in 1671...

.

Ongoing hillslope processes can change the topology of the hillslope surface, which in turn can change the rates of those processes. Hillslopes that steepen up to certain critical thresholds are capable of shedding extremely large volumes of material very quickly, making hillslope processes an extremely important element of landscapes in tectonically active areas.

On Earth, biological processes such as burrowing or tree throw
Tree throw
A tree throw or tree hole is a bowl-shaped cavity or depression created in the subsoil by a tree.They are formed either by the long term presence and growth of tree roots or when a large tree is blown over or has its stump pulled out which tears out a quantity of soil along with the roots...

 may play important roles in setting the rates of some hillslope processes.

Glacial processes



Glacier
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

s, while geographically restricted, are effective agents of landscape change. The gradual movement of ice
Ice
Ice is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...

 down a valley causes abrasion
Abrasion (geology)
Abrasion is the mechanical scraping of a rock surface by friction between rocks and moving particles during their transport by wind, glacier, waves, gravity, running water or erosion. After friction, the moving particles dislodge loose and weak debris from the side of the rock...

 and plucking
Plucking (glaciation)
Glacial plucking exploits pre-existing fractures in the bedrock. This plays a key role in opening and creating new fractures but has only provided small segments of loose material. This is then followed by the entrainment of the loosened rock by the ice. During the process of entrainment, loose...

 of the underlying rock
Rock (geology)
In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...

. Abrasion produces fine sediment, termed glacial flour. The debris transported by the glacier, when the glacier recedes, is termed a moraine
Moraine
A moraine is any glacially formed accumulation of unconsolidated glacial debris which can occur in currently glaciated and formerly glaciated regions, such as those areas acted upon by a past glacial maximum. This debris may have been plucked off a valley floor as a glacier advanced or it may have...

. Glacial erosion is responsible for U-shaped valleys, as opposed to the V-shaped valleys of fluvial origin.

The way glacial processes interact with other landscape elements, particularly hillslope and fluvial processes, is an important aspect of Plio-Pleistocene
Plio-Pleistocene
The term Plio-Pleistocene refers to the geological period more recent than circa 5 million years ago, incorporating both the formally defined epochs of the Pliocene and the Pleistocene...

 landscape evolution and its sedimentary record in many high mountain environments. Environments that have been relatively recently glaciated but are no longer may still show elevated landscape change rates compared to those that have never been glaciated. Nonglacial geomorphic processes which nevertheless have been conditioned by past glaciation are termed paraglacial
Paraglacial
Paraglacial means unstable conditions caused by a significant relaxation time in processes and geomorphic patterns following glacial climates. Rates of landscape change and sediment output from the system are typically elevated during paraglacial landscape response.When a large mass of ice melts,...

 processes. This concept contrasts with periglacial
Periglacial
Periglacial is an adjective originally referring to places in the edges of glacial areas, but it has later been widely used in geomorphology to describe any place where geomorphic processes related to freezing of water occur...

 processes, which are directly driven by formation or melting of ice or frost.

Tectonic processes


Tectonic
Plate tectonics
Plate tectonics is a scientific theory that describes the large scale motions of Earth's lithosphere...

 effects on geomorphology can range from scales of millions of years to minutes or less. The effects of tectonics on landscape are heavily dependent on the nature of the underlying bedrock
Bedrock
In stratigraphy, bedrock is the native consolidated rock underlying the surface of a terrestrial planet, usually the Earth. Above the bedrock is usually an area of broken and weathered unconsolidated rock in the basal subsoil...

 fabric that more less controls what kind of local morphology tectonics can shape. Earthquake
Earthquake
An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...

s can, in terms of minutes, submerge large extensions creating new wetlands. Isostatic rebound can account for significant changes over thousand or hundreds of years, and allows erosion of a mountain belt to promote further erosion as mass is removed from the chain and the belt uplifts. Long-term plate tectonic dynamics give rise to orogenic belts
Orogeny
Orogeny refers to forces and events leading to a severe structural deformation of the Earth's crust due to the engagement of tectonic plates. Response to such engagement results in the formation of long tracts of highly deformed rock called orogens or orogenic belts...

, large mountain chains with typical lifetimes of many tens of millions of years, which form focal points for high rates of fluvial and hillslope processes and thus long-term sediment production.

Features of deeper mantle
Mantle (geology)
The mantle is a part of a terrestrial planet or other rocky body large enough to have differentiation by density. The interior of the Earth, similar to the other terrestrial planets, is chemically divided into layers. The mantle is a highly viscous layer between the crust and the outer core....

 dynamics such as plumes
Mantle plume
A mantle plume is a hypothetical thermal diapir of abnormally hot rock that nucleates at the core-mantle boundary and rises through the Earth's mantle. Such plumes were invoked in 1971 to explain volcanic regions that were not thought to be explicable by the then-new theory of plate tectonics. Some...

 and delamination
Delamination (geology)
In geophysics, delamination refers to the loss and sinking of the portion of the lowermost lithosphere from the tectonic plate to which it was attached.This can occur when the lower portion of the lithosphere becomes more dense than the surrounding mantle...

 of the lower lithosphere have also been hypothesised to play important roles in the long term (> million year), large scale (thousands of km) evolution of the Earth's topography. Both can promote surface uplift through isostasy as hotter, less dense, mantle rocks displace cooler, denser, mantle rocks at depth in the Earth.

Igneous processes



Both volcanic (eruptive) and plutonic (intrusive) igneous processes can have important impacts on geomorphology. The action of volcanoes tends to rejuvenize landscapes, covering the old land surface with lava
Lava
Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...

 and tephra
Tephra
200px|thumb|right|Tephra horizons in south-central [[Iceland]]. The thick and light coloured layer at center of the photo is [[rhyolitic]] tephra from [[Hekla]]....

, releasing pyroclastic
Pyroclastic flow
A pyroclastic flow is a fast-moving current of superheated gas and rock , which reaches speeds moving away from a volcano of up to 700 km/h . The flows normally hug the ground and travel downhill, or spread laterally under gravity...

 material and forcing rivers through new paths. The cones built by eruptions also build substantial new topography, which can be acted upon by other surface processes.

Biological processes



The interaction of living organisms with landforms, or biogeomorphologic processes
Biogeomorphology
thumb|right|Slope stabilization by [[Chilean rhubarb]] on the coasts of [[Chacao Channel]]. Vegetation have mostly a protective effect on slopes.Biogeomorphology and ecogeomorphology are the study of interactions between organisms and the development of landforms, and are thus fields of study...

, can be of many different forms, and is probably of profound importance for the terrestrial geomorphic system as a whole. Biology can influence very many geomorphic processes, ranging from biogeochemical processes controlling chemical weathering, to the influence of mechanical processes like burrowing and tree throw
Tree throw
A tree throw or tree hole is a bowl-shaped cavity or depression created in the subsoil by a tree.They are formed either by the long term presence and growth of tree roots or when a large tree is blown over or has its stump pulled out which tears out a quantity of soil along with the roots...

 on soil development, to even controlling global erosion rates through modulation of climate through carbon dioxide balance. Terrestrial landscapes in which the role of biology in mediating surface processes can be definitively excluded are extremely rare, but may hold important information for understanding the geomorphology of other planets, such as Mars.

Scales in geomorphology


Different geomorphological processes dominate at different spatial and temporal scales. Moreover, scales on which processes occur may determine the reactivity or otherwise of landscapes to changes in driving forces such as climate or tectonics. These ideas are key to the study of geomorphology today.

To help categorize landscape scales some geomorphologists might use the following taxonomy
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...

:
  • 1st - Continent
    Continent
    A continent is one of several very large landmasses on Earth. They are generally identified by convention rather than any strict criteria, with seven regions commonly regarded as continents—they are : Asia, Africa, North America, South America, Antarctica, Europe, and Australia.Plate tectonics is...

    , ocean basin, climatic zone (~10,000,000 km2)
  • 2nd - Shield, e.g. Baltic Shield
    Baltic Shield
    The Baltic Shield is located in Fennoscandia , northwest Russia and under the Baltic Sea. The Baltic Shield is defined as the exposed Precambrian northwest segment of the East European Craton...

    , or mountain range
    Mountain range
    A mountain range is a single, large mass consisting of a succession of mountains or narrowly spaced mountain ridges, with or without peaks, closely related in position, direction, formation, and age; a component part of a mountain system or of a mountain chain...

     (~1,000,000 km2)
  • 3rd - Isolated sea
    Sea
    A sea generally refers to a large body of salt water, but the term is used in other contexts as well. Most commonly, it means a large expanse of saline water connected with an ocean, and is commonly used as a synonym for ocean...

    , Sahel
    Sahel
    The Sahel is the ecoclimatic and biogeographic zone of transition between the Sahara desert in the North and the Sudanian Savannas in the south.It stretches across the North African continent between the Atlantic Ocean and the Red Sea....

     (~100,000 km2)
  • 4th - Massif, e.g. Massif Central
    Massif Central
    The Massif Central is an elevated region in south-central France, consisting of mountains and plateaux....

     or Group of related landforms, e.g., Weald
    Weald
    The Weald is the name given to an area in South East England situated between the parallel chalk escarpments of the North and the South Downs. It should be regarded as three separate parts: the sandstone "High Weald" in the centre; the clay "Low Weald" periphery; and the Greensand Ridge which...

     (~10,000 km2)
  • 5th - River valley, Cotswolds
    Cotswolds
    The Cotswolds are a range of hills in west-central England, sometimes called the Heart of England, an area across and long. The area has been designated as the Cotswold Area of Outstanding Natural Beauty...

     (~1,000 km2)
  • 6th - Individual mountain
    Mountain
    Image:Himalaya_annotated.jpg|thumb|right|The Himalayan mountain range with Mount Everestrect 58 14 160 49 Chomo Lonzorect 200 28 335 52 Makalurect 378 24 566 45 Mount Everestrect 188 581 920 656 Tibetan Plateaurect 250 406 340 427 Rong River...

     or volcano
    Volcano
    2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...

    , small valleys (~100 km2)
  • 7th - Hillslopes, stream channels, estuary
    Estuary
    An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....

     (~10 km2)
  • 8th - gully
    Gully
    A gully is a landform created by running water, eroding sharply into soil, typically on a hillside. Gullies resemble large ditches or small valleys, but are metres to tens of metres in depth and width...

    , barchannel (~1 km2)
  • 9th - Meter-sized features

Overlap with other fields


There is a considerable overlap between geomorphology and other fields. Deposition of material is extremely important in sedimentology
Sedimentology
Sedimentology encompasses the study of modern sediments such as sand, mud , and clay, and the processes that result in their deposition. Sedimentologists apply their understanding of modern processes to interpret geologic history through observations of sedimentary rocks and sedimentary...

. Weathering
Weathering
Weathering is the breaking down of rocks, soils and minerals as well as artificial materials through contact with the Earth's atmosphere, biota and waters...

 is the chemical and physical disruption of earth materials in place on exposure to atmospheric or near surface agents, and is typically studied by soil scientists
Soil science
Soil science is the study of soil as a natural resource on the surface of the earth including soil formation, classification and mapping; physical, chemical, biological, and fertility properties of soils; and these properties in relation to the use and management of soils.Sometimes terms which...

 and environmental chemists
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....

, but is an essential component of geomorphology because it is what provides the material that can be moved in the first place. Civil
Civil engineering
Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including works like roads, bridges, canals, dams, and buildings...

 and environmental
Environmental engineering
Environmental engineering is the application of science and engineering principles to improve the natural environment , to provide healthy water, air, and land for human habitation and for other organisms, and to remediate polluted sites...

 engineers are concerned with erosion and sediment transport, especially related to canal
Canal
Canals are man-made channels for water. There are two types of canal:#Waterways: navigable transportation canals used for carrying ships and boats shipping goods and conveying people, further subdivided into two kinds:...

s, slope stability
Slope stability
The field of slope stability encompasses the analysis of static and dynamic stability of slopes of earth and rock-fill dams, slopes of other types of embankments, excavated slopes, and natural slopes in soil and soft rock...

 (and natural hazard
Natural hazard
A natural hazard is a threat of a naturally occurring event that will have a negative effect on people or the environment. Many natural hazards are interrelated, e.g. earthquakes can cause tsunamis and drought can lead directly to famine. It is possible that some natural hazards are...

s), water quality
Water quality
Water quality is the physical, chemical and biological characteristics of water. It is a measure of the condition of water relative to the requirements of one or more biotic species and or to any human need or purpose. It is most frequently used by reference to a set of standards against which...

, coastal environmental management, transport of contaminants, and stream restoration
Stream restoration
Stream restoration or river restoration, sometimes called river reclamation in the UK, describes a set of activities that help improve the environmental health of a river or stream. Improved health may be indicated by expanded habitat for diverse species and reduced stream bank erosion...

. Glaciers can cause extensive erosion and deposition in a short period of time, making them extremely important entities in the high latitudes and meaning that they set the conditions in the headwaters of mountain-born streams; glaciology
Glaciology
Glaciology Glaciology Glaciology (from Middle French dialect (Franco-Provençal): glace, "ice"; or Latin: glacies, "frost, ice"; and Greek: λόγος, logos, "speech" lit...

 therefore is important in geomorphology.

See also



  • Badlands
    Badlands
    A badlands is a type of dry terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded by wind and water. It can resemble malpaís, a terrain of volcanic rock. Canyons, ravines, gullies, hoodoos and other such geological forms are common in badlands. They are often...

  • Base level
    Base level
    The base level of a river or stream is the lowest point to which it can flow, often referred to as the 'mouth' of the river. For large rivers, sea level is usually the base level, but a large river or lake is likewise the base level for tributary streams...

  • Bioerosion
    Bioerosion
    Bioerosion describes the erosion of hard ocean substrates – and less often terrestrial substrates – by living organisms. Marine bioerosion can be caused by mollusks, polychaete worms, phoronids, sponges, crustaceans, echinoids, and fish; it can occur on coastlines, on coral reefs, and...

  • Biogeology
    Biogeology
    Biogeology is the study of the interactions between the Earth's biosphere and the lithosphere.Biogeology examines biotic, hydrologic, and terrestrial systems in relation to each other, to help understand the Earth's climate, oceans, and other effects on geologic systems.For example, bacteria are...

  • Biogeomorphology
    Biogeomorphology
    thumb|right|Slope stabilization by [[Chilean rhubarb]] on the coasts of [[Chacao Channel]]. Vegetation have mostly a protective effect on slopes.Biogeomorphology and ecogeomorphology are the study of interactions between organisms and the development of landforms, and are thus fields of study...

  • Biorhexistasy
    Biorhexistasy
    The Theory of Biorhexistasy describes climatic conditions necessary for periods of soil formation separated by periods of soil erosion. Proposed by pedologist H...

  • Coastal erosion
    Coastal erosion
    Coastal erosion is the wearing away of land and the removal of beach or dune sediments by wave action, tidal currents, wave currents, or drainage...

  • Community Surface Dynamics Modeling System
    Community Surface Dynamics Modeling System
    The Community Surface Dynamics Modeling System deals with the Earth's surface and the observable and projected changes constantly taking place...

  • Drainage basin
    Drainage basin
    A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

  • Drainage system (Geomorphology)
    Drainage system (Geomorphology)
    In geomorphology, a drainage system is the pattern formed by the streams, rivers, and lakes in a particular drainage basin. They are governed by the topography of the land, whether a particular region is dominated by hard or soft rocks, and the gradient of the land. Geomorphologists and...

  • Engineering geology
    Engineering geology
    Engineering geology is the application of the geologic sciences to engineering practice for the purpose of assuring that the geologic factors affecting the location, design, construction, operation and maintenance of engineering works are recognized and adequately provided for...

  • Erosion prediction
    Erosion prediction
    There are dozens of erosion prediction models. Most have been developed for agricultural areas and are design to compare predicted annual rates of soil loss from broad areas under various cropland and rangeland management techniques. Some are purely statistical models, others mechanistic...

  • Fluvial landforms of streams
    Fluvial landforms of streams
    The fluvial landforms of streams, stream beds, and river valleys have various landforms.-Classification:*Consequent streams are streams whose course is a direct consequence of the original slope of the surface upon which it developed, i.e., streams that follow slope of the land over which they...

  • Geologic modelling
    Geologic modelling
    Geologic modelling or Geomodelling is the applied science of creating computerized representations of portions of the Earth's crust based on geophysical and geological observations made on and below the Earth surface. A Geomodel is the numerical equivalent of a three-dimensional geological map...

  • Geomorphometry
    Geomorphometry
    Geomorphometry is the science of quantitative land surface analysis. It gathers various mathematical, statistical and image processing techniques that can be used to quantify morphological, hydrological, ecological and other aspects of a land surface. Common synonyms for geomorphometry are...

  • Geotechnics
    Geotechnics
    Geotechnics is the application of scientific methods and engineering principles to the acquisition, interpretation, and use of knowledge of materials of the Earth's crust and earth materials for the solution of engineering problems...


  • Hack's law
    Hack's law
    Hack's law is an empirical relationship between the length of streams and the area of their basins. If L is the length of the longest stream in a basin, and A is the area of the basin, then Hack's law may be written asL = C A^h\...

  • Hydrologic modeling
    Hydrology
    Hydrology is the study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability...

    , behavioral modeling in hydrology
    Behavioral modeling in hydrology
    In hydrology, behavioral modeling is a modeling approach that focuses on the modeling of the behavior of hydrological systems.The behavioral modeling approach makes the main assumption that every system, given its environment, has a most probable behavior...

  • Landscape
    Landscape
    Landscape comprises the visible features of an area of land, including the physical elements of landforms such as mountains, hills, water bodies such as rivers, lakes, ponds and the sea, living elements of land cover including indigenous vegetation, human elements including different forms of...

  • Lithosphere
    Lithosphere
    The lithosphere is the rigid outermost shell of a rocky planet. On Earth, it comprises the crust and the portion of the upper mantle that behaves elastically on time scales of thousands of years or greater.- Earth's lithosphere :...

  • Mound
    Mound
    A mound is a general term for an artificial heaped pile of earth, gravel, sand, rocks, or debris. The most common use is in reference to natural earthen formation such as hills and mountains, particularly if they appear artificial. The term may also be applied to any rounded area of topographically...

  • Physical geography
    Physical geography
    Physical geography is one of the two major subfields of geography. Physical geography is that branch of natural science which deals with the study of processes and patterns in the natural environment like the atmosphere, biosphere and geosphere, as opposed to the cultural or built environment, the...

  • Physiographic regions of the world
    Physiographic regions of the world
    The physiographic regions of the world are a means of defining the Earth's landforms into distinct regions based upon classic 1916 three-tiered approach defining divisions, provinces, and sections...

  • Regolith
    Regolith
    Regolith is a layer of loose, heterogeneous material covering solid rock. It includes dust, soil, broken rock, and other related materials and is present on Earth, the Moon, some asteroids, and other terrestrial planets and moons.-Etymology:...

  • Sediment transport
    Sediment transport
    Sediment transport is the movement of solid particles , typically due to a combination of the force of gravity acting on the sediment, and/or the movement of the fluid in which the sediment is entrained...

  • Soil
    Soil
    Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

  • Soil conservation
    Soil conservation
    Soil conservation is a set of management strategies for prevention of soil being eroded from the Earth’s surface or becoming chemically altered by overuse, acidification, salinization or other chemical soil contamination...

  • Soil mechanics
    Soil mechanics
    Soil mechanics is a branch of engineering mechanics that describes the behavior of soils. It differs from fluid mechanics and solid mechanics in the sense that soils consist of a heterogeneous mixture of fluids and particles but soil may also contain organic solids, liquids, and gasses and other...

  • Soil morphology
    Soil morphology
    Soil morphology is the field observable attributes of the soil within the various soil horizons and the description of the kind and arrangement of the horizons. C.F...

  • Soils retrogression and degradation
    Soils retrogression and degradation
    Soil retrogression and degradation are two regressive evolution processes associated with the loss of equilibrium of a stable soil. Retrogression is primarily due to erosion and corresponds to a phenomenon where succession reverts back to pioneer conditions . Degradation is an evolution,...

  • Stream capture
  • List of important publications in geology


External links