Objective: To evaluate different models for characterizing eutrophication in a reservoir located in the semi-arid region of Araras. Methodology: The assessment of the Trophic Status Index and the risk of eutrophication was carried out using five Trophic Status Index models. The calculation of eutrophication risk using the Probability Density Function was applied to the TSI multi-model assessment to generate the representative value of the Trophic State. Originality/Relevance: The development of the research and the data processing corroborate the need for monitoring reservoirs, combined with integrated water management as a way to allow multiple uses and clarify the influence of hydrological and water quality parameters of water on the Trophic Status Index. Results: The results indicated that, in the period from 2009 to 2022, the Reservoir Volume variable influenced water quality, specifically in its levels of nitrogen, total phosphorus, and chlorophyll, indicating an increased risk of eutrophication as the reservoir emptied. All models used showed discrepancies in the classification of the Trophic State; however, the multi-model assessment associated with the calculation of eutrophication risk proved to be a consistent tool for evaluating the eutrophication of the Araras reservoir. Social/Management Contribuitions: The monitoring of reservoirs and the multi-model assessment provide reliable and consistent information for the adequate management of water quality in reservoirs in the tropical semi-arid region of Brazil.
Raulino et al. (Mon,) studied this question.