Potential of the retention capability of a Neotropical reservoir (São Paulo State, Brazil)

Author(s)

Flavia Bottino ^[1] ; Simone Pereira Casali ^[2] ; Marcela Bianchessi Cunha-Santino ^[3] ; Maria do Carmo Calijuri ^[4] ; Irineu Bianchini Júnior ^[5]

Affiliation

^[1] Instituto Federal de Educação Ciência e Tecnologia de São Paulo - Brasil

^[2] Universidade de São Paulo. Escola de Engenharia de São Carlos. Programa de Pós-Graduação em Engenharia Hidráulica e Saneamento - Brasil

^[3] Universidade Federal de São Carlos. Departamento de Hidrobiologia - Brasil

^[4] Universidade de São Paulo. Escola de Engenharia de São Carlos. Departamento de Hidráulica e Saneamento - Brasil

^[5] Universidade Federal de São Carlos. Departamento de Hidrobiologia - Brasil

• Document type: Journal article
• Source: Acta Limnol. Bras.; v. 35, 2023-03-20.

Abstract

Abstract: Aim Man-made reservoirs lead to several changes in their downstream rivers that depend on the hydraulic characteristics of the reservoirs. However, their multiple uses can also provide facilities that influence the ecosystem services that they provide. This study addressed the potential ability of a Neotropical reservoir to trap chemical species aiming to assess the role of these ecosystems to mitigate pollution. Methods Retention capability modeling was examined for a small subtropical reservoir with high hydraulic retention time (> 100 days). The temporal ranges of 9 physical and chemical water variables over a five-year period were used to calculate the mass balance and to determine the retentive capability (alpha parameter) of the Itupararanga Reservoir (São Paulo State, Brazil). To explain the long-term mass balance of these variables, it was assumed that the reservoir is a completely mixed system with a step input. Results The highest values of parametrized alpha (high retention capability) occurred in wet months (up to 500 mm) for all variables. High reaction rate constants (k) and low hydraulic flushing suggested that sink processes prevail over the export ones, mainly for total phosphorus. The rainfall pattern showed minor importance for trapping elements. Conclusions In the Neotropics, hydraulic characteristics of the ecosystem (e.g., low area:volume ratio) are a tool for pollution management in man-made reservoirs. (AU)

• FAPESP's process: 08/55636-9 - Contribution to carbon cycle in Itupararanga reservoir as subsidy for sustainability in Sorocaba watershed, São Paulo, Brazil
• Grantee: Maria do Carmo Calijuri
• Support Opportunities: Research Projects - Thematic Grants