Classificação automatizada de elementos de relevo no estado do paraná (brasil) por meio da aplicação da proposta dos geomorphons

Abstract

The quantitative approach for landforms treatment, called geomorphometry, has been favored by the increasing availability of Digital Elevation Models (DEMs), by the advances in the development of software and hardware that base the processing in Geographic Information System (GIS) and the methodological contribution to the analysis and mapping of the landforms. In this context, the objective of this study is to carry out the automated classification of landscape elements in the state of Paraná, Brazil, through the implementation of the Geomorphons proposition, to evaluate its distribution in the morpho-sculptural subunits mapped in the Geomorphological Mapping of the State of Paraná, and to evaluate the representativeness of the landform elements supported by field recognition. The applied method, based on the geomorphons concept, analyzes the textural similarity of a DEM, considering the gray level variation between a central cell and neighboring cells from computational vision tools rather than diff erential geometry, by combining DEM's calculated variables. The DEM used was the one from elevation data provided by the project Shuttle Radar Topographic Mission (SRTM), Version 4, with spatial resolution of 3 arcs of second resampled to 90 meters. Nine landform elements distributed throughout the state were found: 1) flats, 2) peaks, 3) ridges, 4) shoulders, 5) spurs, 6) slopes, 7) hollows, 8) footslopes, 9) valley and spits. In the large compartments individualized analysis, the morpho-sculptural subunits of Serra do Mar were characterized by dissected landforms with no flat elements and by the expressive occurrence of elements such as ridges, slopes and valleys. In the Paraná's First Plateau, the most noticeable distinction appears on the high representation of flat areas and footslopes for the subunits of Castro and Alto Iguaçu Plateaus, while the others are characterized by an undulating landform mostly constituted by valleys, slopes and ridges elements. The morpho-sculptural subunits of the Second and Third Plateaus have a distinct distribution of the landform elements in their interior and the subunits of Coastal Plain, Fluvial-Marine Plains, and the River Plains were represented by the flat element. There was a limitation in the representation of Geomorphon 9 (valleys and pits) in the northwest and west of Paraná, located in the Third Plateau; with the grouping in the class of flat areas of the River Plains morpho-sculptural subunits with the interfluvials of the slopes contained in Paranavaí and Foz do Iguaçu Plateaus. In general, the geomorphons proposition implementation for automated classification of landform elements proved to be representative in the state of Paraná. When analyzed from the regional point of view, the identified elements grouping has allowed the visualization of homogeneous geomorphological compartments, and when examined from the local perspective, landform elements showed a reliable relation with the field verification, except in the aforementioned case of the Northwest region of the state.