Geography (from the Greek words Ge (γη) or Gaea (γαια), both meaning "Earth", and graphein (γραφειν) meaning "to describe" or "to write"or "to map") is the study of the Earth's features and of the distribution of life on the earth, including human life and the effects of human activity ^[1]. There are at least four traditional views on geography among geographers where emphasis is on the spatial analysis of natural and human phenomena (geography as a study of distribution), on area studies (places and regions), on man-land relationships, and earth science (study of the earth, its waters, and the atmosphere.)^[2]

Traditionally geography and geographers have been viewed as the same as cartography and the study of place names. Although, many geographers are trained in topography and cartography this is not their main preoccupation, but rather the spatial and temporal distribution of phenomena, processes and feature as well as the interaction of humans and their environment are. ^[3] As space and place affects a variety of topics, including economics, health, climate, plants and animals, geography is highly interdisciplinary.

mere names of places...are not geography...To know by heart a whole gazeteer full of them would not, in itself, constitute anyone a geographer. Geography has higher aims than this: it seeks to classify phenomena (alike of the natural and of the political world, in so far as it treats of the latter), to compare, to generalise, to ascend from effects to causes, and, in doing so, to trace out the great laws of nature and to mark their influences upon man. This is 'a description of the world'—that is Geography. In a word Geography is a Science—a thing not of mere names but of argument and reason, of cause and effect.

— William Hughes 1863^[4]

Geography as a discipline can be split broadly into two main sub fields: human geography and physical geography. The former focuses largely on the built environment and how space is created, viewed and managed by humans as well as the influence humans have on the space they occupy. The latter examines the natural environment and how the climate, vegetation & life, soil, water and landforms and produced and interact. ^[5] As a result of the two subfields using different approaches a third field has emerged, which is environmental geography. Environmental geography combines physical and human geography and looks at the interactions between the environment and humans.^[3]

See main article: History of geography

The foundations of geography can be traced to the ancient cultures, such as the Greeks, who were the first to explore geography as both art and science, whether through Cartography, Philosophy, and Literature, or through Mathematics. There is some debate about who was the first person to assert that the Earth is spherical in shape, with the credit going either to Parmenides or Pythagoras. Anaxagoras was able to demonstrate that the profile of the Earth was circular by explaining eclipses. However he still believed that the Earth was a flat disk, as did many of his contemporaries. One of the first estimates of the radius of the Earth was made by Eratosthenes.^[6]

The first rigorous system of latitude and longitude lines is credited to Hipparchus. He employed a sexagesimal system that was derived from Babylonian mathematics. The parallels and meridians were sub-divided into 360°, with each degree further subdivided 60′ (minutes). To measure the longitude at different location on Earth, he suggested using eclipses to determine the relative difference in time.^[7] The extensive mapping by the Romans as they explored new lands would later provide a high level of information for Ptolemy to construct detailed atlases. He extended the work of Hipparchus, using a grid system on his maps and adopting a length of 56.5 miles for a degree.^[8]

During the Middle Ages, the fall of the Roman empire led to a shift in the evolution of geography from Europe to the Islamic world.^{[citation needed]} Scholars such as Idrisi (produced detailed maps), Ibn Batutta, and Ibn Khaldun provided detailed accounts of their Hajj. Further, Islamic scholars translated and inteperated the earlier works of the Romans and Greeks and established the House of Wisdom in Baghdad for this purpose. ^[9]

The Age of discovery during the 16th and 17th centuries where many new lands were discovered and accounts by explorers such as Christopher Columbus, Marco Polo and James Cook , revived a desire for both accurate geographic detail, and more solid theoretical foundations.^{[citation needed]}

The 18th and 19th centuries were the times when geography became recognized as a discrete academic discipline and became part of a typical university curriculum in Europe (especially Paris and Berlin). The development of many geographic societies also occurred during the 18th century with the foundations of the Société de Géographie in 1821^[10], the Royal Geographical Society in 1830^[11], Russian Geographical Society in 1845 ^[12] and the National Geographic Society in1888^[13]. The influence of Immanuel Kant, Alexander von Humbolt, Carl Ritter and Paul Vidal de la Blache can be seen as a major turning point in geography from a philosophy to an academic subject.

Over the past two centuries the advancements in technology such as computers, has led to the development of geomatics and new practices such as participant observation and geostatistics being incorporated into geography's portofilio of tools. In the West during the 20th century, the discipline of geography went through four major phases: environmental determinism, regional geography, the quantitative revolution, and critical geography. The strong interdisciplinary links between geography and the sciences of geology and botany, as well as economics, sociology and demographics have also grown greatly especially as a result of Earth System Science that seeks to understand the world in a Holistic view.

Physical geography (or physiogeography) focuses on geography as an Earth science. It aims to understand the physical features of the Earth, its lithosphere, hydrosphere, atmosphere, pedosphere and global flora and fauna patterns (biosphere). Physical Geography can be divided into the following broad categories:

• Geomorphology
• Coastal/Marine studies
• Hydrology/Hydrography
  • Glaciology
  • Limnology
  • Oceanography/Oceanology
• Climatology
• Pedology
• Biogeography
• Geodesy
• Palaeogeography and paleoclimatology
• Environmental Geography and management
• Landscape ecology
• Astronomical Geography/Cosmography

Human geography is a branch of geography that focuses on the study of patterns and processes that shape human interaction with various environments. It encompasses human, political, cultural, social, and economic aspects. While the major focus of human geography is not the physical landscape of the Earth (see physical geography), it is hardly possible to discuss human geography without referring to the physical landscape on which human activities are being played out, and environmental geography is emerging as a link between the two.

Human geography can be divided into many broad categories, such as:

• Economic geography
• Transportation geography
• Development geography
• Population geography or Demography*
• Urban geography
• Social geography
• Behavioral geography
• Cultural geography
• Political geography, including Geopolitics*
• Historical geography
• Time geography
• Regional geography
• Tourism geography
• Strategic geography
• Military geography
• Feminist geography
• Children's geographies

* Distinction between these fields of study have become increasingly blurred over time and the above list should not be considered definitive.

During the time of environmental determinism, geography was defined not as the study of spatial relationships, but as the study of how humans and the natural environment interact. Though environmental determinism has lost support, there remains a strong tradition of geographers addressing the relationships between people and nature. There are two main subfields of socio-environmental geography:

• Cultural and Political ecology (CAPE): Cultural ecology grew out of the work of Carl Sauer in geography and a similar school of thought in anthropology. It examined how human societies adapt themselves to the natural environment. Sustainability science has been one important outgrowth of this tradition. Political ecology arose when some geographers used aspects of critical geography to look at relations of power and how they affect people's use of the environment. For example, an influential study by Michael Watts argued that famines in the Sahel are caused by the changes in the region's political and economic system as a result of colonialism and the spread of capitalism.

• Risk-hazards research: Research on hazards began with the work of geographer Gilbert F. White, who sought to understand why people live in disaster-prone floodplains. Since then, the hazards field has expanded to become a multidisciplinary field examining both natural hazards (such as earthquakes) as well as technological hazards (such as nuclear reactor meltdowns). Geographers studying hazards are interested in both the dynamics of the hazard event and how people and societies deal with it. (See main article: Disaster management)

Urban planning, regional planning and spatial planning use the science of geography to assist in determining how to develop (or not develop) the land to meet particular criteria, such as safety, beauty, economic opportunities, the preservation of the built or natural heritage, and so on. The planning of towns, cities and rural areas may be seen as applied geography although it also draws heavily

In the 1950s the regional science movement led by Walter Isard arose, to provide a more quantitative and analytical base to geographical questions, in contrast to the descriptive tendencies of traditional geography programs. Regional science comprises the body of knowledge in which the spatial dimension plays a fundamental role, such as regional economics, resource management, location theory, urban and regional planning, transport and communication, human geography, population distribution, landscape ecology, and environmental quality.

While the discipline of geography is normally concerned with the Earth, the term can also be informally used to describe the study of other worlds, such as the planets of the solar system, and even beyond. The study of systems larger than the earth itself usually forms part of Astronomy or Cosmology. The study of other planets is usually called planetology. Alternative terms such as areology (the study of Mars) have been proposed but are not widely used.

As spatial interrelationships are key to this synoptic science, maps are a key tool. Classical cartography has been joined by a more modern approach to geographical analysis, computer-based geographic information systems (GIS).

• Cartography studies the representation of the Earth's surface with abstract symbols (map making). Although other subdisciplines of geography rely on maps for presenting their analyses, the actual making of maps is abstract enough to be regarded separately. Cartography has grown from a collection of drafting techniques into an actual science. Cartographers must learn cognitive psychology and ergonomics to understand which symbols convey information about the Earth most effectively, and behavioral psychology to induce the readers of their maps to act on the information. They must learn geodesy and fairly advanced mathematics to understand how the shape of the Earth affects the distortion of map symbols projected onto a flat surface for viewing. It can be said, without much controversy, that cartography is the seed from which the larger field of geography grew. Most geographers will cite a childhood fascination with maps as an early sign they would end up in the field.

• Geographic information systems (GIS) deal with the storage of information about the Earth for automatic retrieval by a computer, in an accurate manner appropriate to the information's purpose. In addition to all of the other subdisciplines of geography, GIS specialists must understand computer science and database systems. GIS has revolutionized the field of cartography; nearly all mapmaking is now done with the assistance of some form of GIS software.

• Geostatistics deal with quantitative data analysis, specifically the application of statistical methodology to the exploration of geographic phenomena. Geostatistics is used extensively in a variety of fields including: hydrology, geology, petroleum exploration, weather analysis, urban planning, logistics, and epidemiology. The mathematical basis for geostatistics derives from cluster analysis, discriminant analysis, and non-parametric statistical tests, and a variety of other subjects. Applications of geostatistics rely heavily on Geographic Information Systems, particularly for the interpolation (estimate) of unmeasured points.

• Geographic qualitative methods, or ethnographical; research techniques, are used by human geographers. In cultural geography there is a tradition of employing qualitative research techniques also used in anthropology and sociology. Participant observation and in-depth interviews provide human geographers with qualitative data.

In their study, geographers use four interrelated approaches:

• Systematic - Groups geographical knowledge into categories that can be explored globally.
• Regional - Examines systematic relationships between categories for a specific region or location on the planet.
• Descriptive - Simply specifies the locations of features and populations.
• Analytical - Asks why we find features and populations in a specific geographic area.

• Eratosthenes (276BC - 194BC) - calculated the size of the Earth
• Ptolemy (c.90–c.168) - compiled Greek and Roman knowledge into the book Geographia
• Alexander Von Humboldt (1769–1859) - published the Kosmos and founder of the sub-field biogeography. Founder of modern geography
• Carl Ritter (1779-1859) - Occupied the first chair of geography at Berlin University, founder of modern geography
• William Morris Davis (1850-1934) - father of american geography and developer of the cycle of erosion
• Paul Vidal de la Blache (1845-1918) - founder of the French school of geopolitics and wrote the principles of human geography
• Walter Christaller (1893-1969) - human geographer and inventor of Central Place Theory
• David Harvey (1935-) - Marxist geographer and author on theories on space and urban geography.
• Arnold Henry Guyot (1807-1884) - noted the structure of glaciers and advanced understaning in glacier motion espoecially fast ice flow
• Nigel Thrift (1949-) - originator of non-representational theory
• Michael Frank Goodchild (1944-) - prominent GIS scholar and winner of the RGS founder's medal in 2003
• Colleen Mctague Storrs (1952-) - A doctor of geography at the University of Cincinnati, Storrs revolutionized the field with her views on political geography.

• List of geography topics
• Geographical terms
• List of countries
• Geography reference tables
• Map
• Geographical renaming
• National Geographic Society (United States)
• National Geographic Bee (United States)
• Royal Geographical Society (United Kingdom)
• List of geographers

• Teaching Geography
  • Juicy Geography
  • The Geography-Site
  • Discussion Forum for Geography Teachers
  • Teaching Geography at School and Home. ERIC Digest.
  • ATLAS OF THE WORLD

• Multimedia Geography Resources
  • Google Earth: View the World from your Desktop
  • Flash Animations on Geographical Themes
  • Geography Movies free for download
  • Images of Life on Earth
  • World in the Balance (PBS)

• Geographical Associations and Pressure Groups
  • National Geographic Online
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  • Give Geography its Place
  • Royal Canadian Geographical Society