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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10501 - Hydrology

Projekt

<a href="/cs/project/GC17-00630J" target="_blank" >GC17-00630J: Preferenční transport ve strukturovaných půdách na různých úrovních prostorového měřítka</a><br>

Návaznosti

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

Rok uplatnění

2018

Kód důvěrnosti údajů

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

Název periodika

Journal of Hydrology

ISSN

0022-1694

e-ISSN

1879-2707

Svazek periodika

563

Číslo periodika v rámci svazku

AUG

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

14

Strana od-do

446-459

Kód UT WoS článku

000441492700036

EID výsledku v databázi Scopus

2-s2.0-85048730553