Assessment of digital elevation models to obtain morphometric characteristics in relief transition region

  • Kevin Nunes Ficher Universidade Federal de Viçosa (UFV), Florestal, MG, Brasil Instituto de Ciências Agrárias (IAF).
  • Donizete dos Reis Pereira Universidade Federal de Viçosa (UFV), Florestal, MG, Brasil Instituto de Ciências Agrárias (IAF).
  • Josiane Silva Oliveira Universidade Federal de Viçosa (UFV), Florestal, MG, Brasil Instituto de Ciências Agrárias (IAF).
  • André Quintão de Almeida Universidade Federal do Sergipe (UFS), São Cristovão, SE, Brasil Departamento de Engenharia Agrícola (DEAGRI).
  • Eduardo Morgan Uliana Universidade Federal de Mato Grosso (UFMT), Sinop, MT, Brasil Instituto de Ciências Agrárias e Ambientais (ICAA).
Keywords: srtm, topographical maps, topo to raster.

Abstract

The purpose of this study was to evaluate the performance of Digital Elevation Models (DEMs) in the morphometric characterization of a basin located in a transitional region between the São Francisco Plateau, São Francisco Depression and Espinhaço Range reliefs. For the study, four DEMs were generated by interpolation of the SRTM data and topographic maps, using the Topo To Raster interpolator with and without mapped hydrography support, available in ArcGIS® 9.3 software. Another DEM was obtained from the SRTM original data. From the generated DEMs, the morphometric characteristics of the basin were determined and compared to those obtained from topographic maps, denominated reference (REF), by means of percentage errors. The evaluation was also performed in a qualitative way, comparing the drainage and the basin delineations. In general, the DEMs obtained with the support of the mapped hydrography (SRTM-TRH and CT-TRH) provided the best results, with small errors, mainly for the main morphometric characteristics of the basin, drainage area and main river length, which ranged from 0.38 to 1.12% and 5.28 to 7.07%, respectively. On the other hand, the DEMs generated without the support of the mapped hydrography (SRTM-O, SRTM-TR and CT-TR) presented major errors mainly in determining the drainage area and length of the main river, which varied from 18.1 to 26.6% and 26.7 to 34.4%, respectively. These occurred due to a deviation of the main river in the São Franciscana Depression region, which allows us to conclude on the necessity and importance of evaluating DEMs before their use.


Published
21/01/2019
Section
Papers