Show simple item record Ruhoff, Anderson Luis Castro, Nilza Maria dos Reis Risso, Alfonso 2013-05-06T18:45:31Z 2013-05-06T18:45:31Z 2011
dc.identifier.citation RUHOFF, Luis Anderson; CASTRO, Nilza Maria Reis; RUSSO, Alfonso. Numerical modelling of the topographic wetness index: an analysis at different scales. International Journal of Geosciences, v. 2, n. 4, p. 476-483, 2011. Disponível em: <>. Acesso em: 06 mai. 2013. pt_BR
dc.description.abstract A variety of landscape properties have been modeled successfully using topographic indices such as topog-raphic wetness index (TWI), defined as ln(a/tanβ), where a is the specific upslope area and β is the surface slope. In this study, 25 m spatial resolution from digital elevation models (DEM) data were used to investi-gate the scale-dependency of TWI values when converting DEMs to 50 and 100 m. To investigate the impact of different spatial resolution, the two lower resolution DEMs were interpolated to the original 25 m grid size. In addition, to compare different flow-direction algorithms, a second objective was to evaluate differences in spatial patterns. Thus the values of TWI were compared in two different ways: 1) distribution functions and their statistics; and 2) cell by cell comparison of DEMs with the same spatial resolution but different flow- directions. As in previous TWI studies, the computed specific upstream is smaller, on average, at higher resolution. TWI variation decreased with increasing grid size. A cell by cell comparison of the TWI values of the 50 and 100 m DEMs showed a low correlation with the TWI based on the 25 m DEM. The results showed significant differences between different flow-diretction algorithms computed for DEMswith 25, 50 and 100 m spatial resolution. pt_BR
dc.language.iso eng pt_BR
dc.rights open access pt_BR
dc.subject Resolution pt_BR
dc.subject DEM pt_BR
dc.subject Grid Size pt_BR
dc.subject Wetness index pt_BR
dc.title Numerical modelling of the topographic wetness index: an analysis at different scales pt_BR
dc.type article pt_BR
dc.identifier.doi 10.4236/ijg.2011.24050 pt_BR

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