Impacts of Evaporation-Induced Groundwater Upwelling on Mixing Dynamics in Shallow Wetlands

Geng，Xiaolong1,2; Boufadel，Michel C.3; Li，Hailong4; Na Nagara，Viravid3; Lee，Kenneth5

2023-08-16

10.1029/2023GL104642

Geophysical Research Letters   Impact Factor & Quartile

0094-8276

1944-8007

Groundwater mixing dynamics play a crucial role in the biogeochemical cycling of shallow wetlands. In this paper, we conducted groundwater simulations to investigate the combined effects of evaporation and local heterogeneity on mixing dynamics in shallow wetland sediments. The results show that evaporation causes groundwater and solutes to upwell from deep sediments to the surface. As the solute reaches the surface, evaporation enhances the accumulation of the solute near the surface, resulting in a higher solute concentration than in deep sediments. Mapping of flow topology reveals that local heterogeneity generates spatially varied mixing patterns mainly along preferential flow pathways. The upwelling of groundwater induced by surface evaporation through heterogeneous sediments is likely to create distinct mixing hotspots that differ spatially from those generated by lateral preferential flows driven by large-scale hydraulic gradients, which enhances the overall mixing in the subsurface. These findings have strong implications for biogeochemical processing in wetlands.

contaminant transport evaporation groundwater flow heterogeneity numerical modeling preferential flow

SCI

English

NI Journal Papers

Others

National Science Foundation[2130595];

Geology

Geosciences, Multidisciplinary

WOS:001041905800001

AMER GEOPHYSICAL UNION

GEOSCIENCES

2-s2.0-85166737847

Scopus

1.Department of Earth Sciences,University of Hawai'i at Mānoa,Honolulu,United States
2.Water Resources Research Center,University of Hawai'i at Mānoa,Honolulu,United States
3.Department of Civil and Environmental Engineering,New Jersey Institute of Technology,Newark,United States
4.State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control,School of Environmental Science & Engineering,Southern University of Science and Technology,Shenzhen,China
5.Department of Fisheries and Oceans,Dartmouth,Canada

Geng，Xiaolong,Boufadel，Michel C.,Li，Hailong,et al. Impacts of Evaporation-Induced Groundwater Upwelling on Mixing Dynamics in Shallow Wetlands[J]. Geophysical Research Letters,2023,50(15).

Geng，Xiaolong,Boufadel，Michel C.,Li，Hailong,Na Nagara，Viravid,&Lee，Kenneth.(2023).Impacts of Evaporation-Induced Groundwater Upwelling on Mixing Dynamics in Shallow Wetlands.Geophysical Research Letters,50(15).

Geng，Xiaolong,et al."Impacts of Evaporation-Induced Groundwater Upwelling on Mixing Dynamics in Shallow Wetlands".Geophysical Research Letters 50.15(2023).