Random walk evaluation of Green's functions for groundwater flow in heterogeneous aquifers

Nan，Tongchao1; Wu，Jichun1; Guadagnini，Alberto2; Zeng，Xiankui1; Liang，Xiuyu3,4

2020-09-01

10.1016/j.jhydrol.2020.125029

JOURNAL OF HYDROLOGY   影响因子和分区

0022-1694

1879-2707

The use of the Walk on Grid (WOG) approach for the reliable evaluation of the Green's function associated with groundwater flow scenarios in heterogeneous geologic media is explored. The study rests on the observation that, while the Green's function method (GFM) is one of the most significant and convenient approaches to tackle groundwater flow, Green's function evaluation is fraught with remarkable difficulties in the presence of realistic groundwater settings taking place in complex heterogeneous geologic formations. Here WOG approach is used to simulate pressure dissipation by lattice random walk and establish a quantitative relationship between space-time distribution of random walkers and the Green's function associated with the underlying flow problem. WOG-based Green's function method is tested (a) in three scenarios where analytical formulations are available for the Green's function and (b) in two groundwater flow systems with increased level of complexity. Our results show that WOG can (a) accurately evaluate the Green's function, being highly efficient when the latter can be analytically expressed in terms of infinite series; and (b) accurately and efficiently evaluate temporal evolutions of hydraulic heads at target locations in the heterogeneous systems. As such, a WOG-based approach can be employed as an efficient surrogate model in scenarios involving groundwater flow in complex heterogeneous domains.

Aquifer connectivity Diffusion equation External forcing Feynman-Kac formula Heterogeneity Lattice random walk

SCI ; EI

英语

其他

National Natural Science Foundation of China[41730856][41972245][41602250] ; China Postdoctoral Science Foundation[2017M611782] ; Fundamental Research Funds for the Central Universities[0206-14380032][0206-14380091]

Engineering ; Geology ; Water Resources

Engineering, Civil ; Geosciences, Multidisciplinary ; Water Resources

WOS:000568826300063

ELSEVIER

20202108684298

Groundwater flow ; Hydrogeology ; Random processes ; Function evaluation ; Groundwater resources

Groundwater:444.2 ; Geology:481.1 ; Fluid Flow, General:631.1 ; Numerical Methods:921.6 ; Probability Theory:922.1

ENGINEERING

2-s2.0-85084789717

Scopus

1.Key Laboratory of Surficial Geochemistry of Ministry of Education,School of Earth Sciences and Engineering,Nanjing University,Nanjing,210023,China
2.Dipartimento di Ingegneria Civile e Ambientale (DICA),Politecnico di Milano,Milano,Piazza Leonardo da Vinci 32,20133,Italy
3.Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control,School of Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China
4.State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control,School of Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China

Nan，Tongchao,Wu，Jichun,Guadagnini，Alberto,et al. Random walk evaluation of Green's functions for groundwater flow in heterogeneous aquifers[J]. JOURNAL OF HYDROLOGY,2020,588.

Nan，Tongchao,Wu，Jichun,Guadagnini，Alberto,Zeng，Xiankui,&Liang，Xiuyu.(2020).Random walk evaluation of Green's functions for groundwater flow in heterogeneous aquifers.JOURNAL OF HYDROLOGY,588.

Nan，Tongchao,et al."Random walk evaluation of Green's functions for groundwater flow in heterogeneous aquifers".JOURNAL OF HYDROLOGY 588(2020).