ASSESSING THE THERMAL BEHAVIOR REPRESENTATION OF A SMALL-POLIMITIC-TROPICAL LAKE WITH AN ONE-DIMENSIONAL MODEL

Código

XXIV-SBRH0429

Autores

Barbara Pozzan dos Santos Duarte, Ariel Ali Bento Magalhães, José Rodolfo Scarati Martins, Fábio Paiva da Silva, Fábio Ferreira Nogueira, JOSÉ CARLOS DE MELO BERNARDINO, Maria Cristina Santana Pereira, Lais Ferrer Amorim de Oliveira

Tema

SE04.C - Engenharia Limnológica e Mecânica dos Fluidos Ambiental

Resumo

The thermal behavior of lakes and reservoirs determines the occurrence of stratification and mixing events, on a daily or seasonal pattern. In order to properly use and rely on mathematical models for the assessment of current or future scenarios, the model's performance, limitation and biases must be well known by the modelist. This paper aims to evaluate the capability of a 1DV hydrodynamical model to reproduce reliably the thermal behavior of a small-polimitic-tropical lake. The case study was focused on the Hedberg Dam, located about 90 km from Sao Paulo city, Brazil. It is a 0.23 km²-4.5m depth pond, built in the beginnings of the 19th century. Its hydrological catchment area is partially protected with some sparse urban occupations. The General Lake Model (GLM) was applied for the simulation. With an hourly time-step, the model used morphology characteristics, atmospheric variables and flow as input data. Thermal profiles from high-frequency sensor data were used for the calibration and validation of the model, 2017 and 2018, respectively, during dry and wet periods, and its results were assessed in the light of the model's performance, limitation and biases. The simulation indicate that the reservoir is well represented by the model, responding to the daily and seasonal patterns observed in a tropical-polimitic-shallow lake, suggesting, however, limitations over the hydraulic representation of extreme flood events and the thermal representation after the occurrence of long-term mixing conditions. The model also seems to overestimate the number of short-term mixing events, mainly during the wet season.