Application of satellite remote sensing to North Carolina. Development of a monitoring methodology for trophic states of lakes in North Carolina
Conjunctive study of four shallow coastal plain lakes in northeastern North Carolina and their LANDSAT-2 images demonstrates that it is possible to differentiate between the lakes and their respective trophic states on the basis of the multispectral scanner imagery. The year-long investigation established that monitoring of the trophic states of the lakes on a seasonal basis through application of color additive imagery enchancement techniques is possible. Utilizing a standard setting of the color additive viewer, an investigator can normalize the imagery to an internal standard of constant reflectance characteristics. By comparison of the false color renditions with a standard interference color chart combined with brightness measurements made on the viewer screen, one can relate the lake reflectances to their trophic states. Two or more bands of the imagery are required, and the present study established that for the lakes studied, Band 5 and Band 6 form a good combination.