USING SPOT SATELLITE DATA AND GEOGRAPHIC INFORMATION-SYSTEMS FOR AGRICULTURE AND SILVICULTURE LAND-USE INVENTORIES

Agricultural and silvicultural inventories (which are needed for many reasons including water quality and wetland assessments, forest clear- cut monitoring, and soil moisture and hydrologic modeling) are difficu lt to achieve by conventional methods. An alternative method for obtai ning such inventories has been developed using remote sensing and a ge ographic information system (GIS). Two Systeme Probatoire de l'Observa tion de la Terre (SPOT) satellite scenes were used 1) to classify land uses (urban, water, row crops, clearings, marsh/shadehouse, hardwoods , conifers, and pasture) within portions of the Lower St. Johns River Basin and the Lake George Basin of northeast Florida, and 2) to import the classified images into a GIS database. Results showed that 75.6% of the land was forested (primarily conifers), while 19.8% was in agri culture (mainly pasture). Respective land-use percentages between the two images varied by only a few %, and the approach appears to have pr omise as a practical and reasonably low-cost method for interfacing la nd-use information with other GIS overlays. Spectral variations with s tage of reforestation and/or recropping are also discussed as well.