Análise do emprego de medidas de informação para caracterização espaço-temporal das relações de dependência chuva-vazão

Abstract

Watersheds, in a simplified way, can be interpreted as systems that transform incident rain into flow through interacting processes. Ultimately, the flow series configures the product of these interactions that process rainfall within the system. The spatial-temporal characteristics of the input series and these physical interactions control the dependency relationship between rainfall and flow. The information transferred from input to output is conditioned by physical attributes and the constantly landscape changing. These factors, associated with fluctuations in time and climate, summarize the complexity of representing it. For some time, hydrologists have sought to characterize it with a view to its extrapolation and understanding of this relationship, its complexity and spatial-temporal variability that, in principle, can occur through the characterization of the information present in the rain series and which is effectively transmitted/transformed into streamflow. In the present study, this dependency relationship was analyzed using Information Theory based on two case studies in Brazil. In the first one, we sought to characterize the variation in this relationship promoted by anthropic changes that occurred in a hydrographic basin inserted in a region of intense agricultural development (MATOPIBA). In the second, the dynamics of dependence was evaluated with emphasis on the extremes of variation observed in the hydrological regime in an Amazon basin (River Acre), in view of the importance of this biome for maintaining the dynamics of the climate. The variation of the information measures made it possible to highlight the changes in the dynamics of hydrological processes in the case of the MATOPIBA region. In the Acre river basin, the conflicting pattern of spatial variation exhibited by these measurements during the analyzed flood and dry periods does not allow us to recognize changes in these dynamics and that the extension of the series and the complexity of the system justify this behavior. The study shows evidence about the hypothesis that the quantification of the information contained in the time series and the analysis of its transference can be used to identify the main hydrological processes acting in the basin, configuring a promising approach to support the construction and validation of adequate conceptual structures for hydrological models.