Numerical modelling of the topographic wetness index: an analysis at different scales
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Publication Date: | 2011 |
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Format: | Article |
Language: | eng |
Source: | Repositório Institucional da FURG (RI FURG) |
Download full: | http://repositorio.furg.br/handle/1/3370 |
Summary: | 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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Ruhoff, Anderson LuisCastro, Nilza Maria ReisRisso, Alfonso2013-05-06T18:45:31Z2013-05-06T18:45:31Z2011RUHOFF, 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.2011.24050A 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.engResolutionDEMGrid SizeWetness indexNumerical modelling of the topographic wetness index: an analysis at different scalesinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da FURG (RI FURG)instname:Universidade Federal do Rio Grande (FURG)instacron:FURGORIGINALNumerical Modelling of the Topographic Wetness Index.pdfNumerical Modelling of the Topographic Wetness Index.pdfapplication/pdf1004573https://repositorio.furg.br/bitstream/1/3370/1/Numerical%20Modelling%20of%20the%20Topographic%20Wetness%20Index.pdfbc2b5f67717ce776cef047dacd00ccdaMD51open accessLICENSElicense.txtlicense.txttext/plain; charset=utf-81724https://repositorio.furg.br/bitstream/1/3370/2/license.txt5b92b9704b4f13242d70e45ddef35a68MD52open access1/33702013-05-06 15:45:31.37open accessoai:repositorio.furg.br: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Repositório InstitucionalPUBhttps://repositorio.furg.br/oai/request || http://200.19.254.174/oai/requestopendoar:2013-05-06T18:45:31Repositório Institucional da FURG (RI FURG) - Universidade Federal do Rio Grande (FURG)false |
dc.title.pt_BR.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 Reis Risso, Alfonso |
author_role |
author |
author2 |
Castro, Nilza Maria Reis Risso, Alfonso |
author2_role |
author author |
dc.contributor.author.fl_str_mv |
Ruhoff, Anderson Luis Castro, Nilza Maria 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.issued.fl_str_mv |
2011 |
dc.date.accessioned.fl_str_mv |
2013-05-06T18:45:31Z |
dc.date.available.fl_str_mv |
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.citation.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. |
dc.identifier.uri.fl_str_mv |
http://repositorio.furg.br/handle/1/3370 |
dc.identifier.doi.pt_BR.fl_str_mv |
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 |
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http://repositorio.furg.br/handle/1/3370 |
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eng |
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eng |
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info:eu-repo/semantics/openAccess |
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openAccess |
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