FIGURE 6
IGN has imported suspended sediments brought by the flood tide to Araguari River during the dry season. Thus, the input and output mass balance between URU1 and URU2 has shown sediment accumulation in the floodplain (approximately 6,679 t tidal cycle-1) (Figure 7A). Part of these sediments was likely transported to Gurijuba-Igarapé Novo Channel and, again, to Araguari River (Figure 7A). Qss balance between Araguari River and Urucurituba Channel has shown insignificant SSC contribution upstream river (ARA1) in comparison to the load carried downstream, since the river has clear water and solids get retained by three series of dams (Santos and Cunha, 2015). Therefore, the main sources of solids in lower Araguari River come from URU1 and from Igarapé Tabaco region (Figure 7A). Thus, most sediment load is transported from these two areas via ARA2 during ebb tides.