EFFECT OF DIGITAL ELEVATION MODEL MESH SIZE ON GEOMORPHIC INDICES: A CASE STUDY OF THE IVAÍ RIVER WATERSHED – STATE OF PARANÁ, BRAZIL

Vanessa Cristina Dos Santos, Mhamad El Hage, Laurent Polidori, José Cândido Stevaux

Resumo


Geomorphometry is the science of quantitative description of land surface morphology by the mean of geomorphic indices extracted from Digital Elevation Models (DEMs). The analysis of these indices is the first and most common procedure performed in several geoscience-related subjects. This study aims to assess the impact of mesh size degradation on different local and regional geomorphic indices extracted for GDEM and TOPODATA DEMs. Thus, these  EMs,
having a mesh size of 30 m, were subsampled to 60, 120 and 240 m and then geomorphic indices were calculated using the full resolution DEM and the subsampled ones. Depending on their behavior, these indices are then classified into stable and unstable. The results show that the most affected indices are slope and hydrographic indices such as Strahler order, stream sinuosity and fractal dimension and watershed perimeter, whereas elevation remains stable. It also shows that the effect depends on the presence of the canopy and geological structures in the studied area.


Palavras-chave


Geomorphic indices; Digital Elevation Model; Mesh Size; Scale

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Direitos autorais 2017 Vanessa Cristina Dos Santos, Mhamad El Hage, Laurent Polidori, José Cândido Stevaux

Licença Creative Commons
Esta obra está licenciada sob uma licença Creative Commons Atribuição - NãoComercial 4.0 Internacional.

Boletim de Ciências Geodésicas. ISSN: 1982-2170