Definition: Geographic information
Land Use/Land Cover
Geographic information is:
· information about places on the Earth's surface
· knowledge about where something is
· knowledge about what is at a given location
Geographic information is traditionally 'stored' in analogue format on paper maps. This format has several constraints concerned with the presentation and the content of the information, depending on the scale, the grade of generalisation and the type of the map. Today, geographic information is handled like many other types of information in computerised systems.
Ideal geographic objects have spatial boundaries and a well defined set of attributes, for example land parcels with accurate and precise boundaries surveyed in the field and attributes like ownership, actual use, permitted use, tax value and so on, which apply uniformly to the whole object.
Points, lines and areas delineate these geographic objects in a defined and absolute geographic reference system. Lines are composed by points with exact co-ordinates of the absolute reference system, areas (polygons) are composed by lines. The information on the spatial delineation of such geographic phenomena is called geographic data.
Analogue geographic information systems (=Maps) present those points, lines and areas (areas=polygons) at a specified scale on a piece of paper. Digital geographic information systems store the real world co-ordinates of the geographic objects in numerical format.
Eurostat, "Manual of concepts on land cover and land use information systems (2000 Edition)", Office for Official Publications of the European Communities, Luxembourg, 2001