VARIATION OF BOTTOM SEDIMENTS AND MORPHOLOGICAL EVOLUTION ALONG THE PARAGUAY RIVER’S CORRIDOR, CÁCERES - MATO GROSSO

Abstract

The fluvial processes of erosion and deposition confirm the dynamism of the Paraguay River, highlighting the progressive evolution in the confluence environments with Sepotuba and Cabaçal Rivers, and complexes of bays and fluvial islands. On the fieldwork, vertical and horizontal gratifications were identified with the succession of pioneer vegetation. As well as, the incorporation of sandy deposits to the plain, lateral bars and old fluvial islands from visual analysis of images - temporal scale. Therefore, the bottom sediments play an important role in the dynamics of this system, mainly due to its granulometric variation. In the flooding period, it presented greater heterogeneity, different from that recorded in the ebbing period (sandy material of fine texture). In this case, there is greater sediment mobility in the rainy season (water and sediment entry into the system), while in the drought period, consolidation of the channel deposits. Therefore, the spatial-temporal monitoring of its evolution, from field, cabinet and laboratory techniques, becomes essential, mainly, due to the importance of the morphodynamics of its rivers and the repercussions of its evolution on regional environmental and socioeconomic aspects, such as navigability in the channel and associated activities.