Mistura e estratificação das águas do açude pereira de Miranda-CE, operando próximo ao volume morto

Abstract

In the semi-arid Northeast region of Brazil, where precipitations are seasonal and irregular in the spatio-temporal scales, the aquatic ecosystems are subjected to marked variation in the water level and are vulnerable to the mixing regime and the stratification of water bodies. The aim of this paper is to evaluate the influence of climatic and hydrological factors on the mixing and stratification processes of water body of the Pereira de Miranda weir (Pentecoste, Ceará). The vulnerability to the thermal and chemical stratification processes and the circulation of the water bodies were verified from the data of water temperature, dissolved oxygen, pH and electrical conductivity observed in the pelagic region, and associated with the values of hydraulic retention time, maximum and average depths and precipitation. The Pereira de Miranda weir presented termal and chemical stratifications conditions in the months of March and April. In the other months, there is circulation of the water bodies, with a complete homogenization of the temperature and the DO in the water column, due to the weir decrease. From the results, it was observed that the prolongation and intensification of the drought conditions resulted in changes in the morphometrics, physical and chemical characteristics of the weir, favoring the predominance of the circulation of the water bodies.