Abstract

The fractal characterization of the catchment drainage network arises from the need to better understand how hydrological phenomena occurs, taking into account the influence of geomorphological factors. Thus, physical and fractal characteristics of a catchment integrate important elements to analyze its hydrological behavior. Thus, the objective of this work was to estimate the fractal dimension of 6 sub-catchments with different characteristics by the Box-Counting method and to verify the relationship between fractal dimension of river courses (df) and drainage network (Df) and other watershed characteristics such as main river length, area, perimeter, drainage density and catchment declivity .The study area was a set of six sub-catchments, from the Malacara, Leao, Pavao, Faxinalzinho, Arroio Josafaz, and Forno rivers, which belong to the Mampituba catchment (RS/SC). The form factor (F) and the compactness coefficient (Kc) of the catchments where analyzed and the Box-Counting method was applied to calculate the fractal dimension. The F values found were less than 0.50, and the highest values were for the Faxinalzinho (F = 0.27) and Leao (F = 0.21) catchment and the lowest value for the Malacara catchment (F = 0.09). Kc values were all higher than 1.50, indicating a low tendency to flooding. Given the values of df and Df obtained by the Box-Counting method, it was possible to verify that they were satisfactory, observing that there are significant positive correlations between the fractal dimension with average basin width, area and perimeter of the basins explored in this study. In this sense, the application of the fractal geometry analysis method proved to be a viable methodology, being an important tool in the geometric assessment of a catchment.

Highlights

  • The fractal characterization of the catchment drainage network arises from the need to better understand how hydrological phenomena occurs

  • the objective of this work was to estimate the fractal dimension of 6 subcatchments with different characteristics

  • study area was a set of 6 subcatchmentsof the Malacara

Read more

Summary

INTRODUÇÃO

A bacia hidrográfica é utilizada como a unidade geomorfológica fundamental, em consequência de suas características físicas que governam o fluxo superficial da água. O uso da geometria fractal é uma alternativa para identificar quantitativamente as características de uma bacia hidrográfica e permitir, dessa maneira, conhecer as relações existentes entre os processos hidrológicos (Rodríguez-Iturbe & Rinaldo, 1997). Tarboton et al (1988) confirmam que os fractais fornecem uma estrutura matemática para o tratamento de formas irregulares e complexas, pois exibem padrões semelhantes em diversas escalas (Figura 1). Diversos trabalhos aplicaram o conceito de dimensão fractal na análise da rede de drenagem de bacias hidrográficas, correlacionando com a aplicação das leis de Horton, destacando-se os trabalhos de La Barbera & Rosso (1987), Tarboton et al (1988), Rosso et al (1991), Veltri et al (1996), Agnese et al (1996), Tarboton (1996), Roth et al (1996), Kobiyama & Bueno Junior (2002), Bueno Junior (2002), Silveira (2006), Vestena & Kobiyama (2010) e Tavares et al (2017). O objetivo principal deste trabalho foi estimar a dimensão fractal de 6 sub-bacias com diferentes características (declividade, densidade de drenagem) pelo método de Box-Counting (Contagem de Caixas) e verificar a relação existente entre dimensão fractal e outras características da bacia hidrográfica como declividade e densidade de drenagem

MATERIAL E MÉTODOS
Caracterização das sub-bacias
Dimensão Fractal
Relações entre a dimensão fractal e características físicas das bacias
DISCUSSÃO
Findings
CONCLUSÕES
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call