Abstract

ROSATTO, Héctor G. et al. Accuracy determination for DEMs generated from digitized points from existing mapping: relationship with the algorithm used. Rev. Fac. Cienc. Agrar., Univ. Nac. Cuyo [online]. 2011, vol.43, n.1, pp.1-17. ISSN 1853-8665.

Basic information about watershed relief, drawn from analytical-descriptive methodologies, allows for the physical parameters necessary to the study of natural resources, such as watershed integrated management, environmental impact, soil degradation, deforestation, water resource conservation, among others. All these processes linked to a strong spatial component allow the use of geographic information systems. Digital elevation models (DEMs) and their derivatives are an important component of these data sources. In this work we evaluated DEMs generated from indirect source data (digitized points from existing contour maps) to determine whether elevation accuracy varies with DEM spatial resolution (grid size). We also assessed the possible existence of some interaction between grid size and the software used that could influence the altimetric quality of the DEM. It was concluded that spatial resolution affects DEM quality. We also found that it is possible to find an ideal grid size in terms of the altimetric accuracy and computer weight size of the generated DEM. Regarding the existence of an interaction between grid size and the software used, which could affect the quality of models obtained based on the methodology of source data acquisition, we found that this possibility does exist when the database is generated from digitized points.

Keywords : DEM; Digitalized; Ideal grid size; Grid-software interaction.

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