Estimating the impact of vadose zone heterogeneity on agricultural managed aquifer recharge : A combined experimental and modeling study

Copyright © 2023. Published by Elsevier Ltd..

Agricultural managed aquifer recharge (Ag-MAR) is a promising approach to replenish groundwater resources using flood water and cropland as spreading grounds. However, site selection, particularly the layering of sediment deposits in the subsurface, can greatly influence Ag-MAR efficacy as it controls water flow and solute transport in the vadose zone. In this study, we use the HYDRUS-1D software to simulate water flow and solute transport from the land surface to the groundwater table in three vadose zone profiles (LS, MS, HS) characterized by differing fractions of sand (44 %, 47 %, and 64 %). For each profile, the single- and dual-porosity models (i.e., considering or not nonequilibrium water flow and solute transport) were calibrated using observed surface ponding, soil water content, and KBr breakthrough data. Water flow and bromide transport in the profile with the lowest sand fraction (LS) were best captured using the model that considered both preferential flow and nonequilibrium bromide transport. Water flow and bromide transport in the profile with the highest sand fraction (HS) was best simulated with the model that considered preferential flow and equilibrium bromide transport. Uniform water flow and nonequilibrium bromide transport provided the best fit for the third profile (MS). The degree of preferential flow was highest in the profile with the largest sand fraction (HS), which also showed the largest flow velocities compared to the profiles with lower sand amounts (LS and MS). Preferential flow did not significantly impact the overall water balance (within 3 %), but caused a significant decrease in vadose zone travel times (bromide) by up to 38 %, relative to a single-porosity model fit. Recharge efficiency varied between 88 % and 90 %, while the average travel times from the soil surface to groundwater varied up to 119 % (from 3.6 to 7.9 days) between the three sites. This study demonstrates that similar recharge efficiency can be achieved at sites with differing soil texture profiles, but subsurface heterogeneity can substantially affect contaminant transport processes and their travel times.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:247

Enthalten in:

Water research - 247(2023) vom: 01. Dez., Seite 120781

Sprache:

Englisch

Beteiligte Personen:

Zhou, Tiantian [VerfasserIn]
Levintal, Elad [VerfasserIn]
Brunetti, Giuseppe [VerfasserIn]
Jordan, Spencer [VerfasserIn]
Harter, Thomas [VerfasserIn]
Kisekka, Isaya [VerfasserIn]
Šimůnek, Jiří [VerfasserIn]
Dahlke, Helen E [VerfasserIn]

Links:

Volltext

Themen:

059QF0KO0R
Bromide transport
Bromides
Dual porosity model
HYDRUS-1D
Journal Article
Preferential flow
Sand
Soil
Subsurface runoff
Travel time
Water

Anmerkungen:

Date Completed 27.11.2023

Date Revised 27.11.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.watres.2023.120781

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM364100788