Next Article in Journal
Image-Based Bed Material Mapping of a Large River
Previous Article in Journal
Study on the Single-Multi-Objective Optimal Dispatch in the Middle and Lower Reaches of Yellow River for River Ecological Health
Open AccessArticle

Interplay between Fingering Instabilities and Initial Soil Moisture in Solute Transport through the Vadose Zone

1
Department of Civil Engineering: Hydraulics, Energy and Environment, Universidad Politécnica de Madrid, 28040 Madrid, Spain
2
Department of Earth and Planetary Sciences, University of California Berkeley, Berkeley, CA 94670, USA
3
Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
*
Author to whom correspondence should be addressed.
Water 2020, 12(3), 917; https://doi.org/10.3390/w12030917
Received: 11 February 2020 / Revised: 15 March 2020 / Accepted: 18 March 2020 / Published: 24 March 2020
(This article belongs to the Special Issue Groundwater and Contaminant Transport)
Modeling water flow and solute transport in the vadose zone is essential to understanding the fate of soil pollutants and their travel times towards groundwater bodies. It also helps design better irrigation strategies to control solute concentrations and fluxes in semiarid and arid regions. Heterogeneity, soil texture and wetting front instabilities determine the flow patterns and solute transport mechanisms in dry soils. When water is already present in the soil, the flow of an infiltration pulse depends on the spatial distribution of soil water and on its mobility. We present numerical simulations of passive solute transport during unstable infiltration of water into sandy soils that are prone to wetting front instability. We study the impact of the initial soil state, in terms of spatial distribution of water content, on the infiltration of a solute-rich water pulse. We generate random fields of initial moisture content with spatial structure, through multigaussian fields with prescribed correlation lengths. We characterize the patterns of water flow and solute transport, as well as the mass fluxes through the soil column. Our results indicate a strong interplay between preferential flow and channeling due to fingering and the spatial distribution of soil water at the beginning of infiltration. Fingering and initial water saturation fields have a strong effect on solute diffusion and dilution into the ambient water during infiltration, suggesting an effective separation between mobile and inmobile transport domains that are controlled by the preferential flow paths due to fingering. View Full-Text
Keywords: vadose zone; solute transport; unsaturated flow; infiltration; preferential flow vadose zone; solute transport; unsaturated flow; infiltration; preferential flow
Show Figures

Figure 1

MDPI and ACS Style

Cueto-Felgueroso, L.; Suarez-Navarro, M.J.; Fu, X.; Juanes, R. Interplay between Fingering Instabilities and Initial Soil Moisture in Solute Transport through the Vadose Zone. Water 2020, 12, 917.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop