Modelos digitais de elevação na delimitação automática das sub-bacias do rio Taquari-Antas no Rio Grande do Sul

Abstract

The use of Geographic Information System for automatic generation of river basins, from Digital Elevation Models are of great importance because, while it provides a time saving automates mechanical processes, reduces the number of people involved in work and reduces the subjectivity of the definition. The goal of this work is to study and discuss the qualitative properties and the accuracy of the automatic delineation of watersheds using ASTER-GDEM (30m), TOPODATA (30m) SRTM (90m) digital elevation models, compared with a DEM interpolated with pixel resolution of 90m from topographic maps at scale 1: 50,000, in the basin of river Taquari-Antas, in southern Brazil. It was found that digital elevation models obtained by remote sensors showed quite accurate for delineation of sub-basins in areas with steep slope results, but showed limitations for the generation of drainage in the flat regions of the sub-basin Taquari-Antas. In this case, the use of digital elevation models interpolated from contour lines is a good alternative to solve the problem presented.

Este trabalho abrange a Serra Gaúcha, na região do Vale do Taquari abrangendo os seguintes municípios: Taquari, Antônio Prado, Veranópolis,Bento Gonçalves, Cambará do Sul, Carlos Barbosa, Caxias do Sul, Estrela,Triunfo, Ibiraiaras, São Francisco de Paula, Cambará do Sul, São José dos Ausentes, Arroio Jacaré, Arroio Augusta, Arroio Seca, Arroio Boa Vista, Arroio Sampaio,Arroio Estrela,Arroio Castelhano, Arroio Marrecão, Arroio Retiro, Arroio Biazus, Arroio Tega, Arroio do Inferno, Arroio Mulada, Arroio Pinheiro Alto, Arroio São Tomé, Arroio Bagual. Cobre os seguintes rios: Rio São Marcos, Rio Taquari-Antas, Rio Taquari, Rio Antas,Rio Turvo, Rio Carreiro, Rio Guaporé, Rio Forqueta, Baixo Taquari-Antas, Médio Taquari-Antas, Alto Taquari-Antas,Rio Tainhas, Rio Lageado Grande, Rio Humatã, Rio Forquetinha, ,Rio Taquari-Mirim,Rio Burati, Rio Quebra Dentes,Rio Camisas.