Physical geography

Physical mapmundi.

Physical geography (known at one time as physiography, a term now in disuse) is the branch of geography that studies the earth's surface systemically and spatially. considered as a whole and specifically, the natural geographic space.

It constitutes one of the three great fields of geographic knowledge; the others are human geography, whose object of study includes the humanized geographic space, and regional geography, which offers a unifying approach, studying geographic systems in an integrated manner.

Physical geography is concerned (according to Strahler) with processes that are the result of two major flows of energy: the flow of solar radiation that drives surface temperatures together with the movement of fluids, and the flow of heat from the interior of the Earth that manifests itself in the materials of the upper strata of the earth's crust. These flows interact on the earth's surface, which is the field of study of the physical geographer. There are various geographical disciplines that specifically study the relationships of the components of the earth's surface. Physical geography emphasizes the study and understanding of geographic patterns and processes in the natural environment, abstracting for methodological reasons from the cultural environment that is the domain of human geography. This means that, although the relationships between these two fields of Geography exist and are very important, when one of these fields is studied, it is necessary to exclude the other in some way, in order to deepen the focus and contents.

Geographical methodology tends to relate these fields by providing a secure framework for the location, distribution, and representation of geographic space in addition to employing tools such as geographic information systems or map development that serve both specialties.

On the other hand, the sciences with which it is related and the methods used are usually different in the three fields, although they have in common the human interest in knowing more and better the world in which we live.

Mapmundi based on a compilation of satellite images. Note that the cylindrical projections, modified or not, give an exaggerated image of the polar regions, as seen here, which appear to be the largest covered surface of clouds, which is not true.

Patterns and processes

The Great Aletsch Glacier, in the Swiss Alps south of the Jungfrau Massif, is the largest in Europe.

These two concepts are equivalent to those of structures and systems in systems theory, being that of patterns a concept similar to that of structures and that of processes one similar to that of systems. Again we tend to separate these two concepts individually for methodological reasons since they are not usually separated in nature. The difference between processes and patterns is that in the first case, the time scale is essential and in the second it is not so important: when we are studying the effects of fluvial erosion on the banks of a river, we consider erosion as a process, that is, a phenomenon that occurs over time. On the contrary, when we refer to the characteristics of a river basin, we are doing a study of spatial patterns, that is, we are referring to a certain area, with an extension, relief, climate, flow, vegetation, etc., without referring in detail to how these patterns have been modified over time by geographic processes. In the case of the Aletsch Glacier, ice tongues, intermediate moraines and other structural features of the glacier can be seen. But its slow movement and evolution constitute the current culmination of a process that needs to be analyzed over time.

Stratums discovered by river erosion in the Carpathians.

The same thing happens in the field of geology: historical geology refers to processes that have occurred in geological time, while physical geology refers to the present:^{[citation required]} stratigraphic or geological patterns of the current era and the way in which they are located on the earth's surface. In the case of the strata discovered by fluvial erosion on the left bank of a river in the Carpathians we can see the typical stratigraphic patterns of sedimentary rocks, for example, a normal stratigraphic arrangement would be when the most recent strata are the highest in a stratigraphic succession.

Geoforms in Ischigualasto, caused both by water erosion and wind, especially by the first, topics that take into account the physical geography.

Scientific research basically progresses through analysis: the detailed study of a phenomenon precedes its general understanding (synthesis), although there is no full consensus on this. Thus, many geographers who consider Geography to be a synthetic science have tried to start with the holistic methodology, relying on previous thematic research. This way you can see the definitions.

Concept

• Humboldt considered geography as a cosmology or cosmography, that is, as a physical geography. It is true that he raised in his main works the action and reaction of man to the phenomena and processes of physical geography, but always linked to this science, an idea that appears in his fundamental work Cosmos (remember that there was not yet the Antropic or Human Geography as an independent discipline although some of its subjects were already present in the corographic tradition)
• The Rioduero Geography Dictionary is limited to enumerating the topics included in the field of physical Geography (climatology, geomorphology, oceanography, and continental hydrography, including glaciology).
• The Dictionary of Geographical Terms of F. J. Monkhouse refers to physical Geography as the science that studies those aspects of geography that are embedded with the form and relief of the earth's surface, the configuration, extension and nature of the seas and oceans, the atmosphere that surrounds us and the corresponding processes, the layer of the "natural" soil and vegetation that covers it, that is, the physical environment of the landscape.
• Arthur Newell Strahler, author of a university text of Physical Geography of wide diffusion in many languages, points out that this science is concerned about the processes that are the result of two large energy flows: the flow of solar radiation that directs the temperatures of the surface along with the movements of the fluids, and the flow of heat from the inside of the Earth that is manifested in the materials of the higher strata of the earth's crust. These flows interact on the terrestrial surface that is the field of the physical geographer.
• The Geography Dictionary of Elsevier points out that physical geography studies the components of the physical environment of the Earth (lithosphere, atmosphere, hydroosphere, biosphere), the relationships between itself, its distribution on the surface of the Earth and the changes in the time experienced by natural causes or by human impact. It mentions that the branches of physical geography are geomorphology, oceanography, climatology, terrestrial hydrology, glaciology, biogeography, paleogeography, edaphogeography, including geocriology and landscape study. However, the authors acknowledge that oceanography has developed as an independent discipline.

Fields of study of physical geography

The geographical sciences that study a specific component of the natural space in its relationship with the others are numerous and among the most important can be mentioned:

• Orography. Part of the physical geography that deals with the description and study of the mountains.
• Hydrography and hydrology. The study of the continental waters (basically, rivers, lakes and groundwaters): rivers and their basins, (cauces, flow, hydrographic networks, upper, medium and lower course of the rivers, hydraulic use, river regime, river dynamics, etc.)

• Glaciology, unlike hydrography, is concerned about the bodies of solid water, such as glaciers, polar caps, icebergs, ice rigs, etc.
• The geocriology dedicated to the study of permahielo.
• Oceanography. Ocean study: hydrological, physical, biological, economic characteristics; movements of ocean waters such as waves, tides and ocean currents, etc. In addition, the action of the oceans and seas on the hydrological cycle and on the atmospheric dynamics, which constitute the basis, directly, of meteorology and indirectly, of the weather.
• Coastal geography. It is dedicated to the study of the dynamics of coastal landscapes.
• Biogeography, with its phytogeography branches or geography of plants, zoogeography or geography of animals and landscape ecology.
• Pedology or edaphogeography or geography of soils, which studies soils from a geographical point of view.
• The weather, a science that studies the weather from weather information. An old and valuable handbook of this science is Austin Miller. The development and dissemination of free access programs with satellite images of the earth's surface, including atmospheric patterns and processes (Centers of Action such as anticyclones and depressions) have rapidly increased this science and its interpretation, although the results of new technologies are still to be seen in a more comprehensive and coherent way.
• Geomorphology is the study of the forms of relief on the terrestrial surface (mountains, plateaus or altiplanes, plains and sedimentary basins, volcanoes, etc.). It also includes processes that originated these forms of relief and current geomorphological processes: meteorization, erosion, sedimentation, mass slides, etc. Founded at the beginning of the centuryXX. by U.S. geographer William Morris Davis, today numerous geographers of many nationalities have been developing this discipline, such as the French Jean Tricart, Emmanuel de Martonne, Max Derruau and many others.
• The paleogeography, which is responsible for investigating and rebuilding the geography of past times and their evolution, of great importance to the rest of the physical geography as it serves to better understand the current dynamics of the geography of our planet.
• The study of natural hazards, since despite the fact that the number of natural disasters has not increased significantly in recent years, the number of people affected has increased. It's a subject of human geography, too.

Sciences related to physical geography

The top of the Roraima, the highest tepuy of the Venezuelan Guiana. The curious forms have been produced by erosion, a subject studied by geomorphology.

Due to the wide field of study of physical geography, there are numerous sciences that are related to it, among which we can cite:

• Earth sciences or geosciences, which serve to integrate the knowledge we have of our planet.
• Geology, both historical and structural geology. Also stratigraphy or stratigraphic geology, sedimentology and vulcanology.
• The mathematical geography, commissioned by the study of the Earth as a planet, especially in terms of its form, dimensions, and characteristics, knowledge also linked to the treaties by Geodesy.
• Physics, especially with regard to the meteorology or physics of the atmosphere, also use concepts of basic physics for the study of oceans, lithosphere, geomorphological concepts and processes (or geomorphic) and each of the physical sciences - natural of geographical interest.
• Ecology, as a science that studies the mutual relations between living beings and the terrestrial surface (habitat and ecosystems) with respect to animals (animal ecology), plants (plant ecology) and even human beings (human ecology, cultural ecology).
• Environmental sciences.

Historical evolution of physical geography

Map of Europe by Estrabón.

From the birth of geography as a science during classical Greek times and until the end of the XIX century with the birth From anthropogeography or human geography, geography was in part a natural science: the descriptive study of location and toponymy of all places in the known world. Various works among the best known during that long period could be cited as an example, from those of Strabo (Geography), Eratosthenes (Geography) or Dionysus Periegeta (Periegesis Oiceumene ) in the Ancient Age to those of Alexander of Humboldt (Cosmos) in the XIXth century, in which Geography was considered as a physical-natural science; of course, going through the work Summa de Geografía by Martín Fernández de Enciso () from the early XVI century , where the New World is indicated for the first time.

Between the 18th and 19th centuries, a polemic taken from Geology, between supporters of James Hutton (Thesis of uniformitarianism) and Georges Cuvier (catastrophism) powerfully influenced the field of Geography.

Two processes developed during the 19th century were of great importance in the later development of physical geography: the first was It deals with European colonial imperialism in Asia, Africa, Australia and even the Americas, in search of the raw materials demanded by the Industrial Revolution, which contributed to the creation and investment in the geography departments of the universities of the colonial powers and to the birth and development of national geographical societies, thus giving rise to the process identified by Horacio Capel as the institutionalization of Geography (). One of the most prolific empires in this sense was the Russian. In the middle of the XVIII century numerous geographers are sent by the Russian admiralty on different occasions to carry out geographical surveys in the Siberian Arctic area. Among these is who is considered the patriarch of Russian geography: Mikhail Lomonosov who in the mid-1750s began working at the Department of Geography of the Academy of Sciences to conduct research in Siberia; His contributions in this sense are notable: he demonstrates the organic origin of soils, develops a general law on the movement of ice that still applies in basic terms, thus founding a new geographical branch: glaciology. In 1755, at his initiative, the University of Moscow, which now bears his name, was founded, where he promoted the study of geography and the training of geographers. In 1758 he was appointed director of the Department of Geography of the Academy of Sciences, a position from which he would elaborate a work methodology for geographical surveying, which would guide the most important expeditions and geographical studies in the extensive territory of Russia for a long time. In this way, Lomonosov's line continued and the contributions of the Russian school multiplied through his disciples; already in the XIX century we have great geographers such as Vasili Dokucháyev who carried out works of great relevance as "principle of comprehensive analysis of the territory" and "The Russian Chernozem", the latter being the most important, where he introduces the geographical concept of soil, distinguishing it from a simple geological stratum, and thus founding a new area of geographical study: Pedology or Edaphology. Climatology would also receive a strong boost from the Russian school through Wladimir Peter Köppen whose main contribution, his climatic classification, is still valid today, although with some modifications and improvements. On the other hand, this great physical geographer also contributed to paleogeography through his work & # 34; The climates of the geological past & # 34; for which he is considered the father of the Paleoclimatology. Other Russian geographers who made great contributions to the discipline in this period were N.M. Sibirtsev, Piotr Semiónov, K. D. Glinka, Neustrayev, among others.

The second important process deals with the theory of evolution formulated by Darwin in the middle of the century (which decisively influenced the work of Ratzel, who had an academic training as a zoologist and was a follower of Darwin's ideas) which meant an important impulse in the development of Biogeography.

Another important event in the late 19th century and early XX will give a major impetus to the development of geography and will take place in the United States. This is the work of the famous geographer William Morris Davis, who not only made important contributions to the establishment of the discipline in his country, but also revolutionized the field by developing the theory of the geographic cycle, which he proposed as a paradigm for geography in general, although in reality served only as a paradigm for physical geography. His theory explained that mountains and other geographical features are modeled by the influence of a series of factors that manifest themselves in the geographical cycle. He explained that the cycle begins with the lifting of the relief by geological processes (faults, volcanism, tectonic uplift, etc.). Geographical factors such as rivers and surface runoff begin to create the V-shaped valleys between the mountains (the stage called "youth"). During this first stage, the relief is steeper and more irregular. Over time, streams may carve out wider valleys ('maturity') and then begin to meander, protruding only gently rolling hills ('senescence'). Eventually, it all comes down to what is a flat plain, flat at the lowest possible elevation (called the "base level"). This plain was called by Davis "peneplain" which means "almost a plain". So, the "rejuvenation" it happens and there is another uplift of mountains and the cycle continues. Although Davis's theory is not entirely accurate, it was absolutely revolutionary and exceptional in its time and helped to modernize geography and create the subfield of geomorphology. Its implications prompted countless investigations in different branches of physical geography. In the case of paleogeography, this theory provided a model to understand the evolution of the landscape. For hydrology, glaciology and climatology, it was an impulse as soon as it was investigated as the geographical factors that study, model the landscape and influence the cycle. The bulk of the works of William Morris Davis led to the development of a new branch of physical geography: geomorphology, whose contents until then did not differ from the rest of geography. Soon this branch would present a great development. Some of his disciples made important contributions to different branches of physical and human geography such as Curtis Marbut with his invaluable legacy for pedology, Mark Jefferson, Isaiah Bowman, among others.

Physical geography and its applications

Physical geography integrates the knowledge developed by the most specialized geographic sciences such as geomorphology, climatology, hydrography and hydrology, oceanography, pedology, and many others. All these sciences usually have an applied perspective. On the other hand, new even more specific disciplines have come to develop applied fields within physical geography. Some examples: the geocryology that has been developed in Russia and Canada specializes in the study of permafrost. Coastal geography focuses on the specific study of coastal dynamics, the geography of risks, an approach summarized in an article by Francisco Calvo García-Tornel (), studies the implications of natural risks on human beings.

In general, the greatest applications of physical geography take place in the development of specific subjects of this discipline such as geomorphology, especially fluvial geomorphology; climatology, coastal geomorphology and even oceanography understood as a geography of the sea and not as a physics or geology of the sea, and many other more specific sciences.

Notable Physical Geographers

• Eratosthenes (276-194 BC), who made the first reliable estimate of the known size of the Earth, in addition to being considered the father of the geography.
• Ptolemy (c.90 - c.168), who compiled Greek and Roman knowledge to produce the book Geographia'.
• Abu Rayhān Bīrūnī (973 - 1048 AD), considered the father of geodesy.
• Ibn Sina (Avicena, 980-1037), who formulated the law of superposition and the concept of uniformism in The Book of healing
• Muhammad al-Idrisi (Dreses, 1100 – c.1165), who made the Rogeriana Tabula, the most accurate map of the world in the middle ages.
• Piri Reis (1465 – c.1554), one of its maps is the oldest preserved world map including America and Antarctica.
• Gerardus Mercator (1512–1594), innovated in the field of cartography and was the creator of Mercator's projection.
• Bernhardus Varenius (1622-1650), wrote his important work "General Geography" (1650), the first general vision of geography, which meant the foundation of modern geography.
• Mikhail Lomonosov (1711–1765), father of the Russian geography and founder of glaciology.
• Alexander Von Humboldt (1769–1859) published his book Kosmos and founded the biogeography study.
• Arnold Henry Guyot (1807-1884), who highlighted the structure of glaciers and has allowed to know more about the glacier movement, especially in the fixed ice flow.
• Louis Agassiz (1807-1873), author of a glacial theory that discusses the notion of a stationary cooling land.
• Alfred Russel Wallace (1823-1913), founder of modern biogeography and the Wallace line.
• Vasily Dokuchaev (1840-1903), patriarch of Russian geography and founder of Pedology.
• Wladimir Peter Köppen (1846-1940), the creator of the most important climatic classification and founder of paleoclimatology.
• William Morris Davis (1850–1934), father of the American geography, founder of the American Association of Geographers, co-founder of the National Geographic Society, founder of geomorphology and developer of the geographical cycle theory.
• Sir Ernest Shackleton (1874-1922), Antarctic scout during the heroic age of Antarctic exploration.
• Robert E. Horton (1875–1945), founder of modern hydrology and creator of basic hydrological concepts such as infiltration capacity and runoff.
• J. Harlen Bretz (1882-1981), pioneer of research in the formation of landscapes for catastrophic floods, especially for the floods of Bretz (Missoula).
• Luis García Sainz (1894-1965), one of the precursors of physical geography in Spain.
• Willi Dansgaard (born in 1922), paleoclimatologo and quaaternarist, played a decisive role in the use of oxygen isotopes for dating and was co-identifier of Dansgaard-Oeschger events.
• Hans Oeschger (1927-1998), paleoclimatologist and pioneer in research of ice cores, co-identifier of Dansgaard-Orschger events.
• Richard Chorley (1927-2002), a key element for quantitative revolution and the use of systems theory in geography.
• Sir Nicholas Shackleton (1937–2006), who suggested that climate oscillations over the past millions of years could be related to variations in the orbital and positional relationship between the Earth and the Sun.

Bibliographic sources

• Francisco Calvo García-Tornel: Some issues about risk geography. Barcelona: University of Barcelona, Scripta Nova Magazine Number 10, 15 November 1997.
• MONKHOUSE, F. J. Dictionary of geographical terms. Barcelona: Oikos - Tau, Editors, 1978.
• SAN MIGUEL DE LA CÁMARA, M. Physical Geography. Part one of the work Physical Geology. Barcelona: Manuel Marín & Cía, Publishers, 1958.
• STRAHLER, Arthur N. Physical Geography. New York: John Wiley & Sons, 1960 (Third edition). There is a Spanish translation of Oikos - Tau Editores, Barcelona: 1974, 2007.
• STRAHLER, A. Visualizing Physical Geography. New York: John Wiley & Sons in collaboration with The National Geographic Society, 2008, 626 pp.
• ROJAS, O.(2007). Portal Geography Physical.[online]. University of Concepción, Chile.
• VLADIMIR KOTLYOKOV and ANNA KOMAROVA Elsevier's Dictionary of Geography (in English, Russian, French, Spanish and German). Moscow: Elsevier, 2007.