Assinaturas topográficas humanas (ATH´S) no contexto dos canais derivados multifuncionais e suas repercussões hidrogeomorfológicas

Abstract

This thesis aims to present the study of hydrogeomorphological forms and processes associated with drainage systems altered by artificial open channels. The surveys, in different landscapes, pointed out the multifunctional condition of these channels, guaranteeing regularity of the flows and maintenance that promote the evolution of their anthropic marginal dikes. These structures guarantee to the artificial channels, besides to the expected connections with the natural drainage network, interactions with the dynamics of the slopes. In order to better understand these issues, upper Dourados river (Patrocínio-MG / Brazil) was chosen for analysis, so that in four artificial river channels, 12 monthly scenarios for flow, suspended sediment, turbidity, pH, and physical parameters (temperature, total dissolved solids, conductivity and resistivity) were monitored. The hydrosediment results show the interference of the artificial channels from their dams to the slopes where the surface circulation dynamics are changed, with artificial base levels forming deposits in the slopes. Marginal anthropic dikes interfere on slopes runoff, retaining part of the flows along the channels, and promoting adjacent depositions that (re)model surfaces. In some sections, these structures exceed one meter tall, also isolating the channel of artificial slopes. The vegetation, developed within the channels, revealed an important role in the particle contention and reduction of flows speed so that they generate water with lower turbidity indexes and interesting to the users. The water parameters indicated alterations promoted by these channels in the drainage systems, by the reduction of flows, promoting changes of the acidity, increase in total solids dissolved and changes in the ecosystemic axes. The results allow us to understand the role of open artificial channels in the promotion of artificialized dynamics in the hydrogeomorphological interrelationships (forms / processes) through the accumulation of raised factors. The need for these structures to be addressed in studies related to environmental planning is suggested, allowing a better understanding of watersheds, and the real circulation within them, when carrying these channels, interfering in scientific analysis and management plans.