Spatial objects can be classified into three categories: point objects, line objects, and area objects. A point object is an object with no length (L0), a line object has length (L1), and an area object is the space bounded by lines i.e. length squared (L2). Fields are continuous data varying across the land surface such as topography.
O’Sullivan, David, and David J. Unwin. Geographic Information Analysis. Hoboken, NJ: John Wiley & Sons, Inc., 2003. 5-9.
Geomorphic, or physiographic, regions are broad-scale subdivisions based on terrain texture, rock type, and geologic structure and history. Nevin Fenneman's (1946) three-tiered classification of the United States - by division, province, and section - has provided an enduring spatial organization for the great variety of physical features.
Use forms on this site to obtain rise, set, and transit times for the Sun and Moon; civil twilight beginning and end times; and, lunar phase information.
Since the Quantitative Revolution in geography began in the 1950s, research in the discipline has incorporated more rigorous empirical approaches to methodology and analysis than had previously been employed, particularly in regional subfields. This direction has been further enhanced by the availability of a vast body of spatial data from systems of satellites and other remote sensing technology, and the development of powerful GIS software capable of performing difficult cartographic applications and the realization of mathematical modeling of spatial phenomena in map form. Today, the careers available to college undergraduates majoring in geography trend towards specialized technical positions in government and the private sector; and as a result, many universities have responded with core courses in GIS applications and programming, remote sensing, and spatial analysis. The purposes to which these geographers apply their skills are pragmatic and relevant to conditions that exist today: to name a few, geographic skills are used in city and regional planning, economic development, land management, stewardship of natural and historical resources, demographic research, and emergency management.
Some geographers have expressed concern that the interdisciplinary nature of geography, not crossing disciplines, but crossing within the discipline between physical and human, threatens the identity of geography. However, geography has a wide range of audience with different interests.
Download the essay below which discusses how the field of geography may in fact be strengthened by these interdisciplinary perspectives.