Precipitação e velocidade do vento na oscilação dos níveis d’água do canal São Gonçalo-RS

Abstract

São Gonçalo is an important watercourse, belonging to the Mirim-São Gonçalo hydrographic basin, which has an area of 25,000 km² and is located in the coastal region of the state of Rio Grande do Sul. The Patos lagoon, which maintains a direct connection with the Atlantic Ocean, to Mirim lagoon, considered as a large reservoir of fresh water in southern Brazil. It’s situated in a lowland lowland region and presents great complexity and sensitivity to the fluctuations of water levels, both due to the regime and direction of the winds and the rainfall regime. The objective of this work was to evaluate the influence of wind and precipitation on the oscillation of the water level downstream of the São Gonçalo channel dam. The hypothesis was that the velocity and direction of the wind, along with the precipitation, influence the oscillation of the levels of the São Gonçalo channel. To achieve the objectives, multiple linear simple regression methods were used between water level, precipitation and wind velocities at 2 and 7 m in height and at maximum velocity. To determine the significance of the linear regression models, the Student's t test was used to verify which variables are influencing the level oscillation. Finally, to indicate the degree of precision of the linear regression models evaluated, the methodology of the relative mean square error was applied. The directions of the winds that were most influential in the process of oscillation of the water levels downstream of the São Gonçalo channel were those of the southeast (SE), south (S) and west (O). The variable with the greatest influence on the oscillation process of the water levels downstream of the São Gonçalo channel dam was the maximum wind speed.