REMOTE-SENSING AND GEOGRAPHIC INFORMATION-SYSTEM TECHNIQUES FOR AQUATIC RESOURCE EVALUATION

The spread of aquatic plants in Lake Marion, South Carolina, necessitated an assessment of the trends in vegetation growth and water quality. Aquatic vegetation maps at 1:10,000 and 1:24,000 scale were produced by photogrammetric techniques from color infrared aerial photographs recorded on six dates between 1972 and 1985. These and other vector map products depicting bathymetry and herbicide applications were converted to raster format (25-m grid cells) to form a cartographic database for the 170 km**2 study area. Statistical data on nutrients, dissolved oxygen, biological oxygen demand, and turbidity obtained from South Carolina Department of Health and Environmental Control and U. S. Environmental Protection Agency records were also input to the database. A PC-based GIS was then used to relate macrophyte distributions to environmental factors influencing aquatic plant growth.