Geographic information systems (GIS) are computer systems that allow spatial information, including aerial photographs, to be analyzed, merged and reproduced as maps.
The are 6 main steps to using a GIS tool: input, manipulation, management, query and analysis, overlay analysis and visualization.
This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities. Agenda 21 recommends developing databases and geographical information systems to store and display physical, social and economic information pertaining to agriculture, and the definition of ecological zones and development areas.
The Food and Agriculture Organisation (FAO) has developed several pilot GIS databases to carry out evaluation of marine resources, integrated terrain unit and waterbasins study in Africa. A number of GIS analysis and applications projects have also been implemented. These mainly include: estimation of available arable lands for the major FAO study Agriculture Towards 2010; Africa, South and Central America inland aquaculture site suitability analysis for fish farming potential; soil suitability analysis studies for various crops in Africa; potential food self-sufficiency at high and low input levels; dominant land resources types map for Africa; nutrition profiles map; fish distribution maps for the Mediterranean; World Food Summit support maps. Currently, remote sensing and GIS technology are also being used for Food Insecurity and Vulnerability and Poverty Mapping in FAO, in cooperation with several other agencies.