Abstract

In this study remote sensing was used as an early alert tool for chlorophyll-a changes in a continental aquatic ecosystem in central Chile. To this end, 14 LANDSAT images of Laja Lake (36 degrees 54 'S, 71 degrees 05' W, 1,360 meters above sea level) were taken over a 6-year period. Eleven spectral indexes were calculated. At the same time, chlorophyll-a concentrations were determined experimentally. Correlations between vegetation indices and chlorophyll-a concentrations in different monitoring zones were established. The indices that presented a good correlation were NDVI and GNDVI. A new regression model was developed that allows the primary productivity values of Laja Lake to be estimated using satellite data. Finally, chlorophyll-a maps were created.