Agricultural influence on the hydrogeochemistry of the sub‐basins of the Verde, Entre Ribeiros and Escuro Rivers of Paracatu Hydrographic Basin (MG) – Brazil

Abstract

PurposeOf the numerous hydrogeochemical river‐water transformations provoked by intense and irrational soil practices, heavy metal contamination by agrochemical usage is the most worrisome. Long‐term metal accumulation can be transported by rainwater, during storms, contaminating rivers. Data on this type of contamination are still scarce, principally in developing countries, such as Brazil. This paper aims to evaluate the influence of agricultural activities on the hydrogeochemistry of the Paracatu River's sub‐basins.Design/methodology/approachFrom a total of 77 points along three sub‐basins, water samples were taken for heavy metal and trace element analyses using spectrometry of atomic emission through plasma (ICP‐OES, Spectro Ciros CCD). The principal water‐quality parameters, such as pH, turbidity, conductivity, oxi‐reduction potential, total dissolved solids (TDS), temperature and dissolved oxygen were measured in situ.FindingsBy incorporating a small drainage area at the monitoring points, it was possible to perceive agriculture's influence (in the form of heavy metal contamination from fertilizers and pesticides) on the water courses.Research limitations/implicationsAlthough the research was carried out at a total of 77 points for water collection, data are from just one wet season, and need to be repeated.Practical implicationsThe results demonstrate a need for monitoring the areas involved with agricultural activities, not only along the main river, but also along small streams that compose the Paracatu Basin.Originality/valueThere is no published literature on this subject regarding the three studied basins.