Dynamics of self-regulatory processes in a lowland river due to seasonal changes in certain hydro-ecological and water quality factors

Abstract

This study establishes an evaluable system of relationships among the hydromorphological and water quality factors of a temperate, lowland, regulated watercourse. The aim is to investigate the effects of the environmental factors that cause temporal changes in planktonic algal communities. Measured, real-time and modelled water quality and hydrological data sets were compared during the analysis. It is observed that the same factor can have both positive and negative effects in different periods. Different physiological and morphological characteristics determine environmental tolerance. Chlorophytes, which utilize the red light living in the upper layer, closely correlate with water mirror width (top width). Diatoms need dissolved and suspended silicon and are therefore related to the factors that cause sediment mixing and increased salinity (EC). Cyanobacteria and dinophytes are also able to utilize organic matter (mixotrophy and heterotrophic photosynthesis, respectively). They multiply easily when the organic nutrients that are abundant. In the absence of inorganic nitrogen compounds, cyanobacteria are preferred because of their ability to directly or indirectly take up the N2 molecule. Hydraulic changes have a significant impact on water quality and life processes, including biodiversity.