The study, proposed within the framework of the cooperation with Kenyan Authorities, has been carried out on the
Kenyan part of the Lake Victoria. This lake is one of the largest freshwater bodies of the world where, over the last few
years, environmental challenges and human impact have perturbed the ecological balance. Pollution and sediments loads
from the tributaries rivers and antrophic sources caused a worrying increase of the turbidity level of the lake water.
Secchi transparency index has declined from 5 meters in the 1930s to less than one meter in the 1990s. With the aim of
providing an inexpensive way to gather information linked to the water clarity and quality, a method for remotely sensed
data interpretation, devoted to produce chl (chlorophyll), CDOM (coloured dissolved organic matter) and TSS (total
suspended solids) maps, has been assessed. At this purpose a bio-optical model, based on radiative transfer theory in
water bodies, has been refined. The method has been applied on an image acquired on January 2004 by
ENVISAT/MERIS sensor just a week after an in situ campaign took place. During the in situ campaign a data set for
model refinement and products validation has been collected. This data comprise surface radiometric quantity and
samples for laboratory analyses. The comparison between the obtained maps and the data provided by the laboratory
analysis showed a good correspondence, demonstrating the potentiality of remote observation in supporting the
management of the water resources.