Determination of the junction angle in fluvial channels from georeferenced aerial images from Google Earth Pro and UAV

  • Marco Alésio Figueiredo Pereira Programa de Pós-graduação em Qualidade Ambiental (PPGQA), Universidade FEEVALE (FEEVALE), ERS- 239, nº 2755, CEP 93525-075, Novo Hamburgo, RS, Brazil.
  • Bruno Lippo Barbieiro Programa de Pós-graduação em Qualidade Ambiental (PPGQA), Universidade FEEVALE (FEEVALE), ERS- 239, nº 2755, CEP 93525-075, Novo Hamburgo, RS, Brazil.
  • Marciano Carneiro Departamento de Engenharia, Universidade do Vale do Rio dos Sinos (UNISINOS), Avenida Unisinos, n° 950, CEP 93022-750, São Leopoldo, RS, Brazil.
  • Masato Kobiyama Instituto de Pesquisas Hidráulicas, Departamento de Obras Hidráulicas, Universidade Federal do Rio Grande do Sul (UFRGS), Avenida Bento Gonçalves, n° 9500, CEP 91501-970, Porto Alegre, RS, Brazil.
Keywords: georeferencing, junction angle, law of cosines.

Abstract

The junction angles in fluvial channels are determined from complex erosion and deposition processes, resulting from river-flow dynamics, bed and margin morphology, and so on. Knowledge regarding these angles is important in order to better understand the existing conditions in a basin. In this sense, the objective of the present study was to determine the junction angles on fluvial channels, called α, β and γ, applying the law of cosines. Georeferenced Google Earth Pro images and UAV images were used. Then, the values calculated from the georeferenced aerial images were compared with the values calculated from the minimum energy principle. To visualize and understand the obtained angles, the Junction Angles Diagram was used. The obtained result shows that the methodology using georeferenced aerial images have good performance for determining junction angles on fluvial channels.


Published
10/09/2019
Section
Papers