Hillslope hydrograph separation: The effects of variable isotopic signatures and hydrodynamic mixing in macroporous soil

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F18%3A00322710" target="_blank" >RIV/68407700:21110/18:00322710 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1016/j.jhydrol.2018.05.054" target="_blank" >http://dx.doi.org/10.1016/j.jhydrol.2018.05.054</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jhydrol.2018.05.054" target="_blank" >10.1016/j.jhydrol.2018.05.054</a>

Result language

angličtina

Original language name

Hillslope hydrograph separation: The effects of variable isotopic signatures and hydrodynamic mixing in macroporous soil

Original language description

The prevailing opinion on the temporal origin of water in a hillslope stormflow hydrograph is that the pre-event water represents a dominant fraction. Such conclusion is usually based on hydrograph separation techniques using stable water isotopes (or other conservative tracers) in conjunction with a mass balance approach. In this study, a two-dimensional dual-continuum model was used to study preferential flow of water and transport of Oxygen-18 (O-18) in a vertical cross-section of a hillslope located in a temperate spruce forest. The effects of hydrodynamic mixing and the spatiotemporal variability of isotopic signatures on estimated pre-event/event water fractions in the hillslope discharge were studied by means of numerical simulation experiments. Pre-event and event water contributions to hillslope stormflow were evaluated using a two-component mass balance approach combined with the 2D flow and transport simulations involving real as well as synthetic O-18 signatures. Long-term simulations of O-18 transport in the hillslope segment were compared with the observed O-18 content in soil water and in the hillslope effluent. The results of the long-term simulations indicated significant mixing of pre-event and event water occurring near the subsurface trench and in the soil above the soil bedrock interface where the transfer of O-18 from the soil matrix to the preferential pathways takes place. Despite the dominant role of preferential flow in the generation of hillslope stormflow, the pre-event water formed 52-84% of total subsurface stormflow. The analysis showed that spatially and temporally variable exchange of O-18 between the soil matrix and preferential pathways exerted a primary control on the estimates of the temporal origin of water in the hillslope runoff. It was demonstrated that the degree of hydrodynamic mixing in the flow domain played an important role in the interpretation of the isotope-based hydrograph separation.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10501 - Hydrology

Project

<a href="/en/project/GC17-00630J" target="_blank" >GC17-00630J: Preferential transport in structured soils - multiscale approach</a><br>

Continuities

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

Publication year

2018

Confidentiality

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

Name of the periodical

Journal of Hydrology

ISSN

0022-1694

e-ISSN

1879-2707

Volume of the periodical

563

Issue of the periodical within the volume

AUG

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

14

Pages from-to

446-459

UT code for WoS article

000441492700036

EID of the result in the Scopus database

2-s2.0-85048730553