Particulate heavy metal transport in the lower Paraíba do Sul River basin, southeastern Brazil

Abstract

In the present study an attempt has been made to calculate the mass transfers of suspended particulate matter andassociated heavy metal within the lower portion of the Para ́ıba do Sul River drainage basin and the contribution ofits tributaries. The highest metal loads were related with the highest water flows and, consequently, with the highestsuspended particulate matter loads, which increased both by surface runoff and sediment resuspension. The highestflow month for the total transported load contributed between 34 and 66% of the total metal transported per year.The total load transported during the entire rainy season ranges from 82 to 93% of the total transported load. Theimportance of the tributary input for the total transported load of the Para ́ıba do Sul River was generally lower than10%, although in some months, when the Para ́ıba do Sul River had low water discharge and strong local rain occurred,this increased upto 40%.