LINKING SATELLITE AND FIELD SURVEY DATA, THROUGH THE USE OF GIS, AS IMPLEMENTED IN GREAT-BRITAIN IN THE COUNTRYSIDE-SURVEY 1990 PROJECT

The Institute of Terrestrial Ecology (ITE) has been studying land use and the effects of land use on ecology for two decades. A series of na tional field surveys have been undertaken by the Land Use Section of I TE since 1978, the most recent being Countryside Survey 1990 (CS 1990) . The three-year project brought together field survey and remote sens ing data which were analyzed using Geographical Information Systems (G IS). National and regional land-cover patterns were described and chan ges estimated. The data collected by the field survey part of CS1990 r ecorded stratified samples based on a land classification. Thematic ma ps for surveyed 1-km squares covered physiography, agriculture and sem i-natural vegetation, forestry, structures and boundaries. The same si tes were surveyed in 1984 and 1990 with 14 000 digital maps produced d escribing both years. GIS was used to generate stock figures for each year, and overlay allowed change between survey dates to be estimated. GIS was used to compare data collected from both field survey and sat ellite imagery so that both sets of information could be qualified whe n expressed as national figures. This paper describes the historical d evelopment of the ITE Land Classification, examines the way in which d ata were collected for surveys, with particular reference to Countrysi de Survey 1990, and shows how satellite and field survey data can be l inked through GIS.