Effects of atmospheric correction of Landsat imagery on lake water clarity assessment

BONANSEA, MATIAS; LEDESMA, CLAUDIA; RODRIGUEZ, CLAUDIA; PINOTTI, LUCIO; HOMEM ANTUNES, MAURO

ADVANCES IN SPACE RESEARCH

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2015 vol. 56 p. 2345 - 2355

0273-1177

Empirical relationships between Landsat data and water clarity expressed in terms of Secchi disk transparency (SDT) have been widely used for monitoring and assessment of water quality. The atmosphere affects differently sensor bands depending on the waveband, thus affecting the relationshipsobtained from top-of-atmosphere reflectance. The objective of this study was to evaluate whether thereliability of water clarity can be improved applying atmospheric correction of Landsat imagery. Further, a general predictive algorithm to determine water clarity in the reservoir was developed. Samples of SDTwere taken from Río Tercero reservoir (Argentina). Landsat images were atmospheric corrected using the6S code. Estimated values of SDT with and without atmospheric correction were compared for their differences. Results suggested that atmospheric corrected values of Landsat band 3 and the ratio 1/3proved to be the best predictor of water clarity in the reservoir (R2=0.84). Using the 6S code wedemonstrate the usefulness of atmospheric correction to Landsat data since water clarity algorithm usingsurface reflectance was more reliable than the top-of atmosphere reflectance model.