Applications of quantitative analysis techniques to monitor water quality of Curuai Lake, Brazil

In this paper we discuss the advantages and limitations of the Spectral Angle Mapper (SAM), Continuum-Removal methods (CR) and Derivative Analysis (DA), to study the optically active water components. These techniques were applied to 61 samples collected at Curuai Lake, located in the Amazonian floodplain, Brazil. The data are composed of limnological variables and in situ reflectance spectra. The SAM algorithm succeeded in matching samples displaying similar spectral behavior allowing them to be classified into clusters of similar water types. In addition, measurements of depth, position, width and asymmetry of absorption bands resulting from CR application seem to be a useful tool to investigate the role of the various optical components on the absorption features.