Calibration of mathematical water quality modeling in a river basin under critical conditions

Abstract

In order to assist with the management of water resources, this study aimed to calibrate the water quality model “Ottocoded Critical Basins Analysis” (ABaCO) in a section of the Lambari River, located in the city of Poços de Caldas, Minas Gerais, Brazil, and it is considered qualitatively critical by the “National Water Agency” (ANA). The calibration results, obtained automatically by the Microsoft Excel® tool Solver, showed good adjustments between the simulated and observed concentrations for the following parameters: total nitrogen, organic phosphorus, inorganic phosphorus, and total phosphorus, considering a visual interpretation of the graphics. The other calibrated parameters (BOD, DO, organic nitrogen, ammoniacal nitrogen, and nitrate) obtained satisfactory adjustments. When evaluating the results by coefficient of determination, it was observed that all parameters showed negative values to one or more field campaigns. However, the calibrated values of the parameters can be incorporated into the model to obtain a first view of the river's qualitative situation, aiming to plan, control, and protect water resources to assist in decision‐making and to favor performance of intervention analyses of environmental control measures. Practitioner points Calibration of water quality model in a section of a river located in Brazil considered qualitatively critical; The calibration occurred automatically and manually, when it was necessary, in an Excel® spreadsheet, generated from the water quality model; The automation process was performed by the Excel® Solver tool through the objective function; Through visual interpretation, it was noticed that the calibrated parameters were well adjusted to the data observed in the field; Sensitivity analysis showed that the studied parameters did not show significant differences in relation to the values calibrated for parameters.

Calibration of mathematical water quality modeling applied to a basin located in central region of the state of São Paulo, Brazil

“…The calibration spreadsheet consists of eight worksheets, which contain information about the section to be calibrated, the tributaries of the calibrated section, existing captures and discharges along the calibrated section, the monitoring data of the CETESB, calibration and results plotted in boxplots graphs (Nakamura et al, 2019).…”

Bayesian‐based calibration for water quality model parameters

“…Parameter calibration is a key step in water quality model development, as it determines the simulation and prediction accuracies of the model (Nakamura et al, 2019). As research into aquatic environments and ecology has increased, the structure of water quality models has become increasingly complex.…”

Modelo matemático de avaliação do processo de autodepuração de matéria orgânica em reservatórios

“…Diversos modelos foram desenvolvidos para estudo de qualidade da água em cursos lóticos com soluções analíticas. Nakamura et al (2019) calibrou um modelo matemático para observação da concentração de nitrogênio e fósforo. Em Maleewong (2013), verificam-se: Pimpunchat et al (2009), para poluição em rios ;Jha et al (2007), para balanço de oxigênio; e o já mencionado Streeter & Phelps (1925), entre outros.…”