Physio-Géo (Dec 2008)

La géomatique au service de la caractérisation automatique des réseaux hydrographiques

  • Adrien Paget,
  • Julien Perret,
  • Jean-François Gleyze

DOI
https://doi.org/10.4000/physio-geo.1031
Journal volume & issue
Vol. 2
pp. 147 – 160

Abstract

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Analyzing territorial phenomena is made easier today by Geographical Information Systems, which make it possible to integrate within the same platform geographical and thematic data related to the phenomena under study. In practice, tools and methods provided by GIS propose an integrated way to analyze the phenomena, without explicitly distinguishing the spatial from the contextual factors which explain the phenomena. Nonetheless, geographical data do not amount to a simple cartographic support representing the territorial phenomena, but potentially contain information making the undelying spatial mechanisms of these phenomena explicit. In particular, the geographical data related to the river networks describe the shape and topology of these networks and, for this reason, can provide additional details on their morphometric types. Thanks to the networks typology and the geometric characterizations provided by previous research in geomorphometry, this article shows that it is possible to extract semantic information relative to the various network types by automating their recognition, thanks to quantitative structural indicators built on their topographic representation. This process is implemented on parallel networks, starting from the observation of the angles formed by the networks edges around the junction nodes. By considering the average directions taken by the edges around these nodes, and by studying the angles distributions on the whole study area, it is possible to implement a segmentation method for hydrographic networks, dinstinguishing parallel networks from the other network types.

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