RELATIONSHIP BETWEEN CHLOROPHYLL-A CONCENTRATION AND CYANOBACTERIA CELL DENSITY IN SÃO PAULO RESERVOIRS: A STATISTICAL AND REMOTE SENSING APPROACH

Cyanobacterial blooms pose a significant threat to the quality and availability of water in São Paulo’s public supply reservoirs. These organisms hold medical importance, and their monitoring is mandatory and regulated by specific legislation. Given that existing monitoring programs lack sufficient coverage in terms of frequency and spatial extent across the entire state, this study developed models to estimate cyanobacteria cell density from chlorophyll-a concentration data. The models provided instantaneous results through developed algorithms. Two algorithms were created: the General model and the Hyper ESH model. Both models demonstrated good fit, indicated by R² values of 0.82 and 0.85, respectively. Nevertheless, adjustments are required to enhance the robustness of these estimates. The primary necessary adjustment relates to establishing a method to effectively isolate cyanobacteria cell density data from other algal groups presented in CETESB's Water Quality Reports.