Effect of unsaturated flow on groundwater-river interactions induced by flood event in riparian zone

Zhou，Yunqiu1,2; Liang，Xiuyu1,2; Ma，Enze1; Chen，Kewei1; Zhang，Jiangwei1; Zhang，You Kuan1,3

2023-05-01

10.1016/j.jhydrol.2023.129405

JOURNAL OF HYDROLOGY   Impact Factor & Quartile

0022-1694

A coupled unsaturated–saturated model for groundwater flow in a riparian zone is established to evaluate the impacts of unsaturated zone on groundwater flow and aquifer-river interactions during a flood event. The semi-analytical solutions for hydraulic head and discharge are obtained by the Laplace-Fourier transform and verified with COMSOL Multiphysics. The results show that the groundwater flow induced by a flood wave is significantly influenced by the dimensionless constitutive exponent κ in the moisture characteristic curve: the larger the value of κ, the stronger the water storage capacity of unsaturated zones, leading to smaller fluctuations of the hydraulic head and higher water amount exchanging between an aquifer and river. The present solution approaches to the solution for an unconfined aquifer when κ=100, and approaches to the solution of confined aquifers when κ=0.01. A thicker unsaturated zone causes less hydraulic head change and slower head recession after a flood wave passes. The traditional solution for an unconfined aquifer tends to underestimate the hydraulic head and overestimate the water exchange between the aquifer and river because it neglects the water retention of the unsaturated zone. The solution is applied to field data, and it improves the prediction of hydraulic heads over a previous solution.

Analytical solution Flood event Groundwater Unsaturated zone

English

First ; Corresponding

ENGINEERING

2-s2.0-85150261107

Scopus

1.School of Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China
2.Shenzhen Key Laboratory of Natural Gas Hydrates,Southern University of Science and Technology,Shenzhen,518055,China
3.Department of Earth and Environmental Sciences,University of Iowa,Iowa City,52242,United States

Zhou，Yunqiu,Liang，Xiuyu,Ma，Enze,et al. Effect of unsaturated flow on groundwater-river interactions induced by flood event in riparian zone[J]. JOURNAL OF HYDROLOGY,2023,620.

Zhou，Yunqiu,Liang，Xiuyu,Ma，Enze,Chen，Kewei,Zhang，Jiangwei,&Zhang，You Kuan.(2023).Effect of unsaturated flow on groundwater-river interactions induced by flood event in riparian zone.JOURNAL OF HYDROLOGY,620.

Zhou，Yunqiu,et al."Effect of unsaturated flow on groundwater-river interactions induced by flood event in riparian zone".JOURNAL OF HYDROLOGY 620(2023).