Topographic Wetness Index calculation guidelines based on measured soil moisture and plant species composition

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985939%3A_____%2F21%3A00547082" target="_blank" >RIV/67985939:_____/21:00547082 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/60460709:41320/21:89417 RIV/60460709:41330/21:89937

Výsledek na webu

<a href="https://doi.org/10.1016/j.scitotenv.2020.143785" target="_blank" >https://doi.org/10.1016/j.scitotenv.2020.143785</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.scitotenv.2020.143785" target="_blank" >10.1016/j.scitotenv.2020.143785</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Topographic Wetness Index calculation guidelines based on measured soil moisture and plant species composition

Popis výsledku v původním jazyce

Soil moisture controls environmental processes and spedes distributions, but it is difficult to measure and interpolate across space. Topographic Wetness Index (TWI) derived from digital elevation model is therefore often used as a proxy for soil moisture. However, different algorithms can be used to calculate TWI and this potentially affects TWI relationship with soil moisture and species assemblages. To disentangle insufficiently-known effects of different algorithms on TWI relation with soil moisture and plant species composition, we measured the root-zone soil moisture throughout a growing season and recorded vascular plants and bryophytes in 45 temperate forest plots. For each plot, we calculated 26 TWI variants from a LiDAR-based digital terrain model and related these TWI variants to the measured soil moisture and moisture-controlled species assemblages of vascular plants and bryophytes. A flow accumulation algorithm determined the ability of the TWI to predict soil moisture, while the flow width and slope algorithms had only a small effects. The TWI calculated with the most often used single-flow D8 algorithm explained less than half of the variation in soil moisture and species composition explained by the TWI calculated with the multiple-flow FD8 algorithm. Flow dispersion used in the 1D8 algorithm strongly affected the TWI performance, and a flow dispersion dose to 1.0 resulted in the TWI best related to the soil moisture and spedes assemblages. Using downslope gradient instead of the local slope gradient can strongly decrease TWI performance. Our results clearly showed that the method used to calculate TWI affects study conclusion. However, TMI calculation is often not specified and thus impossible to reproduce and compare among studies. We therefore provide guidelines for TWI calculation and recommend the FD8 flow algorithm with a flow dispersion close to 1.0, flow width equal to the raster cell size and local slope gradient for TWI calculation.

Název v anglickém jazyce

Topographic Wetness Index calculation guidelines based on measured soil moisture and plant species composition

Popis výsledku anglicky

Soil moisture controls environmental processes and spedes distributions, but it is difficult to measure and interpolate across space. Topographic Wetness Index (TWI) derived from digital elevation model is therefore often used as a proxy for soil moisture. However, different algorithms can be used to calculate TWI and this potentially affects TWI relationship with soil moisture and species assemblages. To disentangle insufficiently-known effects of different algorithms on TWI relation with soil moisture and plant species composition, we measured the root-zone soil moisture throughout a growing season and recorded vascular plants and bryophytes in 45 temperate forest plots. For each plot, we calculated 26 TWI variants from a LiDAR-based digital terrain model and related these TWI variants to the measured soil moisture and moisture-controlled species assemblages of vascular plants and bryophytes. A flow accumulation algorithm determined the ability of the TWI to predict soil moisture, while the flow width and slope algorithms had only a small effects. The TWI calculated with the most often used single-flow D8 algorithm explained less than half of the variation in soil moisture and species composition explained by the TWI calculated with the multiple-flow FD8 algorithm. Flow dispersion used in the 1D8 algorithm strongly affected the TWI performance, and a flow dispersion dose to 1.0 resulted in the TWI best related to the soil moisture and spedes assemblages. Using downslope gradient instead of the local slope gradient can strongly decrease TWI performance. Our results clearly showed that the method used to calculate TWI affects study conclusion. However, TMI calculation is often not specified and thus impossible to reproduce and compare among studies. We therefore provide guidelines for TWI calculation and recommend the FD8 flow algorithm with a flow dispersion close to 1.0, flow width equal to the raster cell size and local slope gradient for TWI calculation.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10618 - Ecology

Projekt

<a href="/cs/project/GA17-13998S" target="_blank" >GA17-13998S: Lesní mikroklima - přehlížený článek mezi diverzitou rostlin a klimatickou změnou</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Science of the Total Environment

ISSN

0048-9697

e-ISSN

1879-1026

Svazek periodika

757

Číslo periodika v rámci svazku

25 February

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

10

Strana od-do

143785

Kód UT WoS článku

000604432900063

EID výsledku v databázi Scopus

2-s2.0-85096555917