Geography is much more than space and place; it is a way of learning about the world by examining spatial patterns and relationships. Of particular interest to geographers is how physical/natural systems, such as weather and climate, and human activities and features such as politics, culture, and economics, vary and relate to one another over space. The nexus between human activities and natural systems is also therefore an important part of the geographic discipline (an area that overlaps significantly with environmental science).
Major Branches of Geography: The three-legged stool
Geography is considered by many to have three major branches or components: 1) human geography, which involves the study of human activities and their spatial patterns, 2) physical geography, which concentrates on natural systems, and 3) geographic techniques, such as geographic information systems (GIS), remote sensing, and spatial statistics, which are used to analyze and understand spatial patterns (either human, physical, or environmental). Environmental geography concerns the interactions between elements of human and physical geography, and often involves the use of geographic techniques.
Physical geographers study a wide variety of natural phenomena and their spatial patterns such as landscape features (geomorphology and landscape ecology), surface waters (hydrology), living organisms and ecosystems (biogeography), atmospheric dynamics (meteorology and climatology), and ocean currents and ecology (oceanography). There is some overlap with geology as well, particularly in regard to soils (pedology) and patterns of surface-level fracturing of rock.
Human geographers concentrate on the built environment and the activities and interactions of people over space. Primary sub-branches of human geography include political geography, economic geography, cultural geography, health/medical geography, demography, and urban geography. Many of these categories overlap and interact with one another. In urban geography, for example, one can examine the political, economic, or cultural features of a single city or multiple cities. A frequent challenge for those studying human geography is collecting data in a controlled setting; it’s possible to set up an hydrology experiment in the lab and tweak the conditions, for example, but nearly impossible to alter just one factor affecting a human population in order to observe the effects.
Qualitative vs. Quantitative Methods
Depending on what a geographer is studying, they might use qualitative or quantitative methods, or a mix of both. Prior to the 1950s, geography was primarily a descriptive endeavor; regions and places were compared and contrasted in an attempt to understand variations over space and the processes giving rise to those variations. Today, a variety of qualitative methods including observations, surveys, and interviews (when human subjects are involved) are still frequently used in geographic research. Quantitative methods are often employed alongside or in place of qualitative data collection, and generally involve some form of statistical analysis. There are a variety of spatial statistics that can be applied to better understand spatial patterns — a particularly powerful ability in the age of ‘big data’.
The creation of maps is often a critical step in analyzing and understanding spatial patterns, as well as communicating those spatial patterns and their implications to others. The art and science of map-making is known as cartography. Almost all mapping today is done on the computer using a GIS.
Within the GIS software program it is possible to overlay several different data layers to examine potential spatial relationships. For example, by overlaying precipitation and vegetation data one can see that grasslands tend to arise in semi-arid environments, while forests need more rainfall. Any number of data layers can be combined, analyzed, and ultimately displayed as a map using a GIS. Map projections can also be easily applied within a GIS to most accurately represent the shape and size of spatial features. Other software packages such as Adobe Illustrator can be used to enhance a map’s aesthetic beyond what’s possible today with the most popular GIS programs.
Geographers often perform their analyses over large areas of the Earth’s surface. For these broad scale investigations it is simply impractical to collect all the necessary data on the ground and out in the field. Remote sensing, or the collection of data at a distance, is therefore often employed by geographers. Most often, a sensor is placed on an aircraft or satellite and the imaging device records light reflecting off the surface of the Earth, essentially taking a photograph of a defined area. The recorded data can then be analyzed using a GIS or other software. Remotely-sensed data has proven invaluable in tracking large-scale changes in the Earth system, such as those associated with climate change.
While geographers use many of the same techniques to examine spatial patterns, the subject can be far ranging. Ranging from the physical sciences to the humanities, geography has one of the broadest scopes of any discipline. This is seen as a strength as it tends to bring different people together with varying interests and backgrounds to tackle complex and urgent problems. It may also be a weakness, however, as those working in particular areas of physical geography may find little common ground with those working on the socio-cultural side of geography, and vice versa. There is therefore often a tension within the field of geography that is seldom seen in the other physical or social sciences.