ÍNDICE DE QUALIDADE DA ÁGUA EM CÓRREGOS COM TRECHOS URBANOS SOB INFLUÊNCIA DO USO E OCUPAÇÃO DO SOLO – ESTUDO DOS CÓRREGOS CAMPESTRE E GALINHA

Abstract

There are growing debates related to environmental issues, seeking new alternatives that reduce the impacts resulting from the various polluting sources, which in the context come to be the water quality under the use and occupation of the soil. Thus, the objective of this work was to study the relationships of land use and occupation in the water quality of the São Tomás de Baixo basin, belonging to the Campestre and Galinha streams in the municipality of Rio Verde (GO). For this, a map of the spatio-temporal evolution of land use and occupation between the years 1985, 1995, 2005, 2015 and 2021 was made for the classes defined as forest area, agricultural area, urbanized area to evaluate the urbanization process. A total of eight collection campaigns were carried out at different points of the streams, covering the periods of drought and rain. The parameters evaluated were hydrogen potential – pH, sample temperature (°C), turbidity (NTU) and dissolved oxygen (mg-L ̄¹), thermotolerant coliforms (NMP-100mL ̄¹), biochemical oxygen demand – BDO₅²° (mg-L ̄¹), total nitrogen (mg-L ̄¹), total phosphorus (mg-L ̄¹) and total solids (mg-L ̄¹) that were submitted to the statistical treatments of descriptive analysis, analysis of variance and Person's correlation, between the points collected. Subsequently, the Water Quality Index (WQI) was calculated. The forest area that in the year 1985 corresponded to 19.45% of the area of the basin, in the year 2021 reached 12.67% and the urbanized area that in 1985 corresponded to 17.45% in the year 2021 reached 48.65% of the area of the São Tomás de Baixo watershed. All the parameters analyzed had at some point in non-compliance with the legislation CONAMA 357/2005. The mean points of the parameters dissolved oxygen, pH, thermotolerant coliforms, BOD, had significant differences. The mean values of WQI at point P1 presented poor quality, at points P2 and P3 presented acceptable quality and at points P4, P5 and P6 presented good quality. The interference of land use and occupation in water quality, therefore, was observed in this study.