Comparação entre modelos digitais de elevação para aplicação em mapeamento digital de solos

Abstract

The Digital Elevation Models (DEMs) are representative models of the earth's surface which, among its many applications can generate core geomorphometric variables to explain the variability of soils in a given location. These models should be compatible with the scale of mapping adopted to achieve a better understanding of soil-landscape relationships. The aim of this study was to evaluate different DEMs (ASTER and model derived from topographic maps of the DSG), to support the choice of the most appropriate model to provide terrain attributes for use in a digital soil mapping in scale 1: 50000. The study area was the perimeter of Carajazinho topographic map in scale 1: 50000 (sheet: SH.21-XB-VI-1, MI - 2930/1), this includes the municipalities of São Miguel das Missões, Eugenio de Castro, Entre-Ijuís and Jóia. Located in the physiographic region known missions in the northwest of the state of Rio Grande do Sul, Brazil. The DEMs were manipulated in a GIS environment. The evaluation of the DEMs was carried out by determining the square root of the mean squared error of the elevation (RMSE) as the Cartographic Accuracy Standards (PEC), and evaluation of the characteristics of the hydrographic features of the original database of the letters and the IBGE drainage derived. The DEM LETTER got a better representation of the ground surface, and can be used to obtain geomorphometric for application in digital soil mapping in the study area.