On the calculation of the topographic wetness index: evaluation of different methods based on field observations
The topographic wetness index (TWI, ln(a/tanβ)), which combines local upslope contributing area and slope, is commonly used to quantify topographic control on hydrological processes. Methods of computing this index differ primarily in the way the upslope contributing area is calculated. In this stud...
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fttriple:oai:gotriple.eu:oai:doaj.org/article:16954219e2cd486cb9b318e062c34bee 2023-05-15T17:44:45+02:00 On the calculation of the topographic wetness index: evaluation of different methods based on field observations R. Sørensen U. Zinko J. Seibert 2006-01-01 http://www.hydrol-earth-syst-sci.net/10/101/2006/hess-10-101-2006.pdf https://doaj.org/article/16954219e2cd486cb9b318e062c34bee en eng Copernicus Publications 1027-5606 1607-7938 http://www.hydrol-earth-syst-sci.net/10/101/2006/hess-10-101-2006.pdf https://doaj.org/article/16954219e2cd486cb9b318e062c34bee undefined Hydrology and Earth System Sciences, Vol 10, Iss 1, Pp 101-112 (2006) envir geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2006 fttriple 2023-01-22T19:12:02Z The topographic wetness index (TWI, ln(a/tanβ)), which combines local upslope contributing area and slope, is commonly used to quantify topographic control on hydrological processes. Methods of computing this index differ primarily in the way the upslope contributing area is calculated. In this study we compared a number of calculation methods for TWI and evaluated them in terms of their correlation with the following measured variables: vascular plant species richness, soil pH, groundwater level, soil moisture, and a constructed wetness degree. The TWI was calculated by varying six parameters affecting the distribution of accumulated area among downslope cells and by varying the way the slope was calculated. All possible combinations of these parameters were calculated for two separate boreal forest sites in northern Sweden. We did not find a calculation method that performed best for all measured variables; rather the best methods seemed to be variable and site specific. However, we were able to identify some general characteristics of the best methods for different groups of measured variables. The results provide guiding principles for choosing the best method for estimating species richness, soil pH, groundwater level, and soil moisture by the TWI derived from digital elevation models. Article in Journal/Newspaper Northern Sweden Unknown |
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English |
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envir geo R. Sørensen U. Zinko J. Seibert On the calculation of the topographic wetness index: evaluation of different methods based on field observations |
topic_facet |
envir geo |
description |
The topographic wetness index (TWI, ln(a/tanβ)), which combines local upslope contributing area and slope, is commonly used to quantify topographic control on hydrological processes. Methods of computing this index differ primarily in the way the upslope contributing area is calculated. In this study we compared a number of calculation methods for TWI and evaluated them in terms of their correlation with the following measured variables: vascular plant species richness, soil pH, groundwater level, soil moisture, and a constructed wetness degree. The TWI was calculated by varying six parameters affecting the distribution of accumulated area among downslope cells and by varying the way the slope was calculated. All possible combinations of these parameters were calculated for two separate boreal forest sites in northern Sweden. We did not find a calculation method that performed best for all measured variables; rather the best methods seemed to be variable and site specific. However, we were able to identify some general characteristics of the best methods for different groups of measured variables. The results provide guiding principles for choosing the best method for estimating species richness, soil pH, groundwater level, and soil moisture by the TWI derived from digital elevation models. |
format |
Article in Journal/Newspaper |
author |
R. Sørensen U. Zinko J. Seibert |
author_facet |
R. Sørensen U. Zinko J. Seibert |
author_sort |
R. Sørensen |
title |
On the calculation of the topographic wetness index: evaluation of different methods based on field observations |
title_short |
On the calculation of the topographic wetness index: evaluation of different methods based on field observations |
title_full |
On the calculation of the topographic wetness index: evaluation of different methods based on field observations |
title_fullStr |
On the calculation of the topographic wetness index: evaluation of different methods based on field observations |
title_full_unstemmed |
On the calculation of the topographic wetness index: evaluation of different methods based on field observations |
title_sort |
on the calculation of the topographic wetness index: evaluation of different methods based on field observations |
publisher |
Copernicus Publications |
publishDate |
2006 |
url |
http://www.hydrol-earth-syst-sci.net/10/101/2006/hess-10-101-2006.pdf https://doaj.org/article/16954219e2cd486cb9b318e062c34bee |
genre |
Northern Sweden |
genre_facet |
Northern Sweden |
op_source |
Hydrology and Earth System Sciences, Vol 10, Iss 1, Pp 101-112 (2006) |
op_relation |
1027-5606 1607-7938 http://www.hydrol-earth-syst-sci.net/10/101/2006/hess-10-101-2006.pdf https://doaj.org/article/16954219e2cd486cb9b318e062c34bee |
op_rights |
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1766147028512931840 |