Impact of Infiltration Rate on Residual Air Distribution and Hydraulic Conductivity

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F19%3A00332781" target="_blank" >RIV/68407700:21110/19:00332781 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68407700:21720/19:00332781

Výsledek na webu

<a href="https://doi.org/10.2136/vzj2019.01.0003" target="_blank" >https://doi.org/10.2136/vzj2019.01.0003</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.2136/vzj2019.01.0003" target="_blank" >10.2136/vzj2019.01.0003</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Impact of Infiltration Rate on Residual Air Distribution and Hydraulic Conductivity

Popis výsledku v původním jazyce

The dynamics of water infiltration into soil have a strong influence on the subsequent distribution of air trapped inside pores. We present results of two infiltration experiments conducted on an artificially prepared sample under ponding and drip irrigation boundary conditions, with concurrent neutron imaging of the sample. A cylindrical sample was packed with two grades of sand and disks of fine porous ceramic in an axially symmetrical geometry. The configuration of the sample provided a number of interfaces between regions of higher and lower hydraulic conductivity. Infiltration was started in dry media. The bottom boundary condition was seepage face. Water was applied on the sample surface during the experiment with drip irrigation at a water application rate about one order of magnitude lower than the minimum flux reached during the ponding experiment. Despite this low application rate, ponding eventually occurred on the top of the sample due to an unexpectedly low infiltration rate. Neutron tomographic imaging revealed massive air entrapment in the coarse sand regions of the sample during slow infiltration under drip irrigation conditions. In contrast, during the ponded infiltration experiment, the air was mostly flushed out from the coarse sand regions by gravity-driven water flow due to greater hydraulic head. Neutron imaging showed that the capillary barrier effect, air entrapment, and entrapped air redistribution were responsible for the observed low infiltration capacity of the sample during the slow-infiltration-dominated drip irrigation experiment. It is reasonable to assume that similar phenomena can occur in natural soils having highly heterogeneous structures.

Název v anglickém jazyce

Impact of Infiltration Rate on Residual Air Distribution and Hydraulic Conductivity

Popis výsledku anglicky

The dynamics of water infiltration into soil have a strong influence on the subsequent distribution of air trapped inside pores. We present results of two infiltration experiments conducted on an artificially prepared sample under ponding and drip irrigation boundary conditions, with concurrent neutron imaging of the sample. A cylindrical sample was packed with two grades of sand and disks of fine porous ceramic in an axially symmetrical geometry. The configuration of the sample provided a number of interfaces between regions of higher and lower hydraulic conductivity. Infiltration was started in dry media. The bottom boundary condition was seepage face. Water was applied on the sample surface during the experiment with drip irrigation at a water application rate about one order of magnitude lower than the minimum flux reached during the ponding experiment. Despite this low application rate, ponding eventually occurred on the top of the sample due to an unexpectedly low infiltration rate. Neutron tomographic imaging revealed massive air entrapment in the coarse sand regions of the sample during slow infiltration under drip irrigation conditions. In contrast, during the ponded infiltration experiment, the air was mostly flushed out from the coarse sand regions by gravity-driven water flow due to greater hydraulic head. Neutron imaging showed that the capillary barrier effect, air entrapment, and entrapped air redistribution were responsible for the observed low infiltration capacity of the sample during the slow-infiltration-dominated drip irrigation experiment. It is reasonable to assume that similar phenomena can occur in natural soils having highly heterogeneous structures.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20101 - Civil engineering

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2019

Kód důvěrnosti údajů

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

Název periodika

Vadose Zone Journal

ISSN

1539-1663

e-ISSN

—

Svazek periodika

18

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

15

Strana od-do

—

Kód UT WoS článku

000480304100001

EID výsledku v databázi Scopus

2-s2.0-85070670337