Physical geography

Physical geography, also called physiography, is one of the three major branches of geography. It is a natural science focused on the processes and patterns found in the natural environment, including the atmosphere, hydrosphere, biosphere, and geosphere. This sets it apart from human geography, which studies the built environment, and technical geography, which deals with the development and application of tools for gathering, analyzing, interpreting, and understanding spatial data. Still, these three branches often overlap significantly.

Physical geography itself splits into several sub-branches. Geomorphology studies Earth’s surface and the processes—both past and present—that shape it. It includes specialized fields like desert and fluvial geomorphology, but all are linked by core driving forces such as tectonic or climatic activity. Geomorphologists use field observation, physical experiments, and numerical modeling (geomorphometry) to understand landform history and dynamics and to predict future changes. Early work in this area laid the groundwork for pedology, one of the two main branches of soil science.

Hydrology focuses on the movement and storage of water on land, in soils, and in near-surface rocks, with the hydrological cycle as its central concept. It covers rivers, lakes, aquifers, and, to some extent, glaciers, examining the processes and dynamics within these water bodies. Historically tied to engineering, hydrology has developed largely quantitative methods, but it also has an earth science side that uses a systems approach. Subfields include limnology and ecohydrology.

Glaciology is the study of glaciers, ice sheets, and the broader cryosphere—any ice and related phenomena. It groups ice sheets as continental glaciers and valley glaciers as alpine glaciers. Research on ice sheets tends to focus on their interaction with current climate, while glacier research emphasizes their impact on the landscape. Subfields include snow hydrology and glacial geology.

Biogeography examines the geographic patterns of species distribution and the processes behind them. Alfred Russel Wallace helped establish this field, but until the late twentieth century it was largely historical and descriptive. Key drivers of the field have been evolution, plate tectonics, and island biogeography theory. It is divided into five main subfields: island biogeography, paleobiogeography, phylogeography, zoogeography, and phytogeography.

Climatology studies climate, defined as average weather conditions over a long period. It looks at both local (micro) and global (macro) climates, as well as natural and human influences on them. The field is often split into regional climates and the study of specific phenomena or time periods, such as tropical cyclone rainfall climatology and paleoclimatology.

Soil geography deals with the spatial distribution of soils across the landscape. Sitting between geography and soil science, it is essential to both physical geography and pedology. Pedology examines soils in their natural environment, covering pedogenesis, soil morphology, and soil classification. Soil geography looks at how soil distribution relates to topography, climate (water, air, temperature), soil life (microorganisms, plants, animals), and mineral materials within soils (biogeochemical cycles).

Palaeogeography is a cross-disciplinary field that uses preserved material in the stratigraphic record to map the distribution of continents through geologic time. Most evidence for past continental positions comes from fossils or paleomagnetism. This data has supported theories of continental drift, plate tectonics, and supercontinents, and has underpinned palaeogeographic concepts like the Wilson cycle.

Coastal geography studies the dynamic boundary between ocean and land, combining physical geography (coastal geomorphology, geology, and oceanography) with human geography. It covers coastal weathering processes, especially wave action, sediment movement, and weathering, as well as human interactions with the coast. While primarily geomorphological in research, it also addresses the causes and effects of sea level change.

Oceanography is the branch of physical geography that investigates Earth’s oceans and seas. It covers a broad range of topics: marine organisms and ecosystem dynamics (biological oceanography); ocean currents, waves, and geophysical fluid dynamics (physical oceanography); plate tectonics and seafloor geology (geological oceanography); and the fluxes of chemical substances and physical properties within the ocean and across its boundaries (chemical oceanography).