Numerical modelling of the topographic wetness index: an analysis at different scales
Autor(a) principal: | |
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Data de Publicação: | 2011 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da FURG (RI FURG) |
Texto Completo: | http://repositorio.furg.br/handle/1/3370 |
Resumo: | 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. |
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Numerical modelling of the topographic wetness index: an analysis at different scalesResolutionDEMGrid SizeWetness indexA 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.2013-05-06T18:45:31Z2013-05-06T18:45:31Z2011info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfRUHOFF, 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: <www.scirp.org>. Acesso em: 06 mai. 2013.http://repositorio.furg.br/handle/1/337010.4236/ijg.2011.24050engRuhoff, Anderson LuisCastro, Nilza Maria dos ReisRisso, Alfonsoinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da FURG (RI FURG)instname:Universidade Federal do Rio Grande (FURG)instacron:FURG2023-10-27T16:57:20Zoai:repositorio.furg.br:1/3370Repositório InstitucionalPUBhttps://repositorio.furg.br/oai/request || http://200.19.254.174/oai/requestopendoar:2023-10-27T16:57:20Repositório Institucional da FURG (RI FURG) - Universidade Federal do Rio Grande (FURG)false |
dc.title.none.fl_str_mv |
Numerical modelling of the topographic wetness index: an analysis at different scales |
title |
Numerical modelling of the topographic wetness index: an analysis at different scales |
spellingShingle |
Numerical modelling of the topographic wetness index: an analysis at different scales Ruhoff, Anderson Luis Resolution DEM Grid Size Wetness index |
title_short |
Numerical modelling of the topographic wetness index: an analysis at different scales |
title_full |
Numerical modelling of the topographic wetness index: an analysis at different scales |
title_fullStr |
Numerical modelling of the topographic wetness index: an analysis at different scales |
title_full_unstemmed |
Numerical modelling of the topographic wetness index: an analysis at different scales |
title_sort |
Numerical modelling of the topographic wetness index: an analysis at different scales |
author |
Ruhoff, Anderson Luis |
author_facet |
Ruhoff, Anderson Luis Castro, Nilza Maria dos Reis Risso, Alfonso |
author_role |
author |
author2 |
Castro, Nilza Maria dos Reis Risso, Alfonso |
author2_role |
author author |
dc.contributor.author.fl_str_mv |
Ruhoff, Anderson Luis Castro, Nilza Maria dos Reis Risso, Alfonso |
dc.subject.por.fl_str_mv |
Resolution DEM Grid Size Wetness index |
topic |
Resolution DEM Grid Size Wetness index |
description |
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. |
publishDate |
2011 |
dc.date.none.fl_str_mv |
2011 2013-05-06T18:45:31Z 2013-05-06T18:45:31Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
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: <www.scirp.org>. Acesso em: 06 mai. 2013. http://repositorio.furg.br/handle/1/3370 10.4236/ijg.2011.24050 |
identifier_str_mv |
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: <www.scirp.org>. Acesso em: 06 mai. 2013. 10.4236/ijg.2011.24050 |
url |
http://repositorio.furg.br/handle/1/3370 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.source.none.fl_str_mv |
reponame:Repositório Institucional da FURG (RI FURG) instname:Universidade Federal do Rio Grande (FURG) instacron:FURG |
instname_str |
Universidade Federal do Rio Grande (FURG) |
instacron_str |
FURG |
institution |
FURG |
reponame_str |
Repositório Institucional da FURG (RI FURG) |
collection |
Repositório Institucional da FURG (RI FURG) |
repository.name.fl_str_mv |
Repositório Institucional da FURG (RI FURG) - Universidade Federal do Rio Grande (FURG) |
repository.mail.fl_str_mv |
|
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1807384413915316224 |