Simulação da dinâmica da biomassa fitoplanctônica em um reservatório do semiárido brasileiro através da aplicação de modelo quali-quantitativo

Abstract

The global problem involving water quality, especially in continental water bodies, has been aggravated in recent years. The eutrophication process caused by the enrichment of nutrients, mainly phosphorus and nitrogen, can result in the excessive growth of algal biomass, being accelerated, many times, by the impacts of anthropic activities. The dynamics of this biomass depends on the availability of resources, light and nutrients, which are influenced by the hydrology of the system, especially the fluctuation of the stored water volume, being of fundamental importance to understand the drivers of this dynamic. Thus, the objective of this study was to apply a mathematical and ecological model with qualitative-quantitative water simulations, developed based on the characteristics of the Brazilian tropical semi-arid region, in a water supply, considering that the availability of light and the variation of volume water act as the main limiting factors in the growth of the phytoplankton community. The results obtained showed that the model follows a trend of the observed data and that it responded well to changes in the amount of water stored and the availability of light in the water column, during the monitoring carried out in the reservoir between 2012 and 2014. The decrease in the volume stored in the reservoir favored the development and growth of primary productivity, and the model proved to be able to work more adequately under eutrophication conditions at intermediate levels of chlorophyll-a, proving to be relevant in decision-making on water resources management in periods of water crisis due to prolonged drought events.