Seasonal analysis of aquatic water quality in a forestry area, MS, Brazil

Abstract Water quality is one of the world's greatest concerns as it is a fundamental resource for life, and it must constantly be monitored. This study aimed to carry out seasonal monitoring of water quality in the hydrographic basin of the Urutu-MS stream, which is occupied by more than 50% of eucalyptus silviculture forests. Water samples were collected from five points seasonally between autumn 2019 and summer 2020. In total, twenty-three parameters were included, including temperature (Cº), pH, Dissolved Oxygen (DO, mg/L), Conductivity (EC ), Total Alkalinity (ALK), Organic Matter (OM), Chloride (Cl), Sulfate (SO42), Total Iron (Fe Total), Color, Turbidity (NTU), Total Dissolved Solids (TDS), Total Suspended Solids (TSS), Chemical Oxygen Demand (COD), Total Phosphorus (PT), Hardness, Aluminum (Al), Manganese (Mn), Magnesium (Mg), Sodium (Na), Calcium (Ca), Copper (Cu) and Dissolved Iron (Fe). The results showed that there is a difference in water quality between the seasons of the year depending on the different concentrations of physical-chemical parameters. Among the seasons, spring was classified in class II, while the others were classified in class I, showing the influence of the onset of rains after the dry winter. Interactions between parameters also followed conventional associations such as ALK and EC, TDS and EC, Color and Turbidity, TSS and Turbidity, EC and Ca, EC and Mg. The ALK and TDS were the main parameters that showed an influence of seasonality.