Determination of water quality parameters and their usefulness on lake modelling

Abstract

The successful launch of ENVISAT in March 2002 has given a great opportunity to understand the optical changes of water surfaces, including inland waters such as lakes and reservoirs, through the use of the Medium Resolution Imaging Spectrometer (MERIS). The potential of this instrument to describe variations of optically active substances has been examined in the Alqueva reservoir, located in the south of Portugal, where satellite spectral radiances are corrected for the atmospheric effects to obtain surface spectral reflectance. In order to validate these spectral reflectances, several field campaigns were carried out, with a portable spectroradiometer, during the satellite overpasses. The retrieved lake surface spectral reflectance was combined with limnological laboratory data to obtain empirical algorithms and with the resulting equations, spatial maps of biological quantities and turbidity were built up.