ADJUSTMENT CAPACITY TO HYDROLOGIC REGIME CHANGES IN INTERMITTENT RIVER – RIVER STYLES OF UPPER PARAIBA RIVER ON PARAÍBA SEMIARID

Abstract

Anthropogenic interventions aimed at changes, permanent or temporary, in the hydrological regime of channels alter not only fluvial processes but can also generate changes in the morphologies of channels. Thus, understanding the possibilities of adjusting the river morphology is essential for analyzing the impact of these adaptations, allowing us to identify which controlled areas were modified. In this perspective, the objective article evaluates the adjustment capacity of the different river styles of the upper course in the Paraíba semi-arid region of Paraíba. The methodology of fluvial styles was used, through which it was possible to characterize the different stretches of the channel and the adjustment capacity of each stretch based on the morphology/texture of the channel and associated morphological units. The analysis identified four river styles, reflecting the low environmental variability and highlighting the predominance of unconfined stretches with sandy bars, which have a high adjustment capacity. Thus, it is possible to understand that predominantly the area has a high capacity for lateral and vertical adjustments, with the possibility of removing/modifying the sandy bars. Among the possible modifications, the stabilization of sandy bars by vegetation stands out, allowing the formation of islands and the lateral expansion of channels, recurrent behaviour for this type of hydrological alteration.