FIGURE 2
The IGN station recorded considerable Qnet increase (891
m³s-1) during the rainy season. In this case, it is
essential emphasizing that positive Qnet has indicated
water outflow inversely proportional to what happened during the dry
season. ARA1 station recorded Qnet = 3,137
m³s-1 and maintained positive discharge values during
the tidal cycle, even during the flood phase. On the other hand, URU2
station recorded maximum Qnet value = 3,688
m³s-1, whereas URU1 station reached maximum
Qnet value of the same order (3,165
m³s-1). Qnet recorded for URU2 and
URU1 in the rainy season were 6.7 and 4.1 times higher than the ones
recorded in the dry period, respectively. This outcome suggests
progressively increased loss of flow from Araguari River to Amazon
River.
The dry season at URU1 section has significantly varied in comparison to
the rainy season (Figure 2). However, this variation was even greater in
comparison to results observed by Santos et al. (2018), who recorded
Qnet = 897 m³s-1 during the rainy
season (March 2015) (Figure 3). Thus, Qnet recorded in
the present study, in May 2018, was approximately 353% higher than that
of 3 years before. There was also considerable Qnetincrease of approximately 162% in IGN between two dry seasons
(September 2014 and October 2017), although on a smaller scale (Figure
3). This outcome suggests dynamic and progressive hydrological and
hydrosedimentary processes.