PROPENSION TO RIVERS MODIFICATION FROM THE SENSITIVITY OF FLUVIAL STYLES IN A HYDROGRAPHIC BASIN IN THE SEMI-ARID OF PARAÍBA

Abstract

The concept of sensitivity has been lost in recent years among works that deal with the theme of evolution and recovery of semi-arid river environments. The concept and methodology of sensitivity identifies and comprises river sections that are prone to change. The objective of this research was to understand the propensity to change channels based on the identification of the levels of sensitivity in each river style in the hydrographic basin of the upper course of the Piranhas River, a semi-arid region in Paraíba. Some geoindicators were analyzed that allowed to point out the possible changes in the fluvial environment of each style, which were: the channel morphology, channel plan and the bed characteristics. It was possible to identify six fluvial styles, according to their valley characteristics, geomorphic units and texture. The confined styles showed low sensitivity due to the controls on the banks and bedrock. EFNCRC showed high sensitivity, due to moderate flow energy and moving margins. Finally, a statistical analysis was made based on the data of the sinuosity index applied in each style, which provided a greater understanding of the different changes in the plan shape of the analyzed river styles, seeking to quantify the river adjustments.