Simulation of seawater intrusion and optimization of cutoff wall schemes based on surrogate model

Abstract In the present study, a 3-D variable density mathematical model for seawater intrusion (SI) was built in Longkou City, China. Based on the model, a cutoff wall construction scheme suitable for the study area was proposed, and the mathematical model was used to simulate and predict the effects of the cutoff wall. By introducing the seawater desalination technology into the construction of the cutoff wall, the optimization model was built with the minimum cost as the objective function, and the simulation model was embedded into the optimization model for calculation. To reduce the huge amounts of computations caused by calling the simulation model repeatedly, a surrogate model of the simulation model was built using the Kriging method. The optimal control plan was obtained by solving the optimization model. The results show the following: 1. The 3-D variable density groundwater intrusion model built with calibration and verification is a reliable method of risk assessment of SI. 2. The surrogate model can significantly reduce the computational load while ensuring accuracy. 3. Using the optimization model based on the surrogate model, the optimal solution can be quickly yielded for the design of the cutoff wall, and it is an effective way for the risk management of SI.

[1]  Application of a newly developed column test device to analyze seawater transport in sandy soils , 2013, Environmental Earth Sciences.

[2]  Frédéric Nguyen,et al.  Characterization of seawater intrusion using 2D electrical imaging , 2009 .

[3]  Jesús Carrera,et al.  Optimal design of measures to correct seawater intrusion , 2006 .

[4]  Peiyue Li,et al.  Conjunctive use of groundwater and surface water to reduce soil salinization in the Yinchuan Plain, North-West China , 2018 .

[5]  C. Paniconi,et al.  A modelling study of seawater intrusion in the Korba coastal plain, Tunisia , 2001 .

[6]  Ying Zhao,et al.  Optimization of Denser Nonaqueous Phase Liquids-contaminated groundwater remediation based on Kriging surrogate model , 2013 .

[7]  Desheng Dash Wu,et al.  Introduction to the Special Section on “Optimizing Risk Management: Methods and Tools” , 2009 .

[8]  Ashraf Ahmed,et al.  The effectiveness of cutoff walls to control saltwater intrusion in multi-layered coastal aquifers: Experimental and numerical study. , 2017, Journal of environmental management.

[9]  Sonja Kuhnt,et al.  Design and analysis of computer experiments , 2010 .

[10]  Xin Xin,et al.  Surrogate model application to the identification of an optimal surfactant-enhanced aquifer remediation strategy for DNAPL-contaminated sites , 2013, Journal of Earth Science.

[11]  W. Sanford,et al.  Current challenges using models to forecast seawater intrusion: lessons from the Eastern Shore of Virginia, USA , 2010 .

[12]  V. Kaleris,et al.  The effect of cutoff walls on saltwater intrusion and groundwater extraction in coastal aquifers , 2013 .

[13]  Ajay K. Singh Optimization modelling for seawater intrusion management , 2014 .

[14]  Peiyue Li,et al.  Geochemistry, Hydraulic Connectivity and Quality Appraisal of Multilayered Groundwater in the Hongdunzi Coal Mine, Northwest China , 2018, Mine Water and the Environment.

[15]  P. Xue,et al.  Saltwater intrusion into the Changjiang River: A model‐guided mechanism study , 2009 .

[16]  P. Marinos,et al.  Simulation of Seawater Intrusion in Coastal Aquifers: Forty Five-Years Exploitation in an Eastern Coast Aquifer in NE Tunisia , 2012 .

[17]  Paul P. Wang,et al.  MT3DMS: A Modular Three-Dimensional Multispecies Transport Model for Simulation of Advection, Dispersion, and Chemical Reactions of Contaminants in Groundwater Systems; Documentation and User's Guide , 1999 .

[18]  J. Carrera,et al.  A correction factor to account for mixing in Ghyben‐Herzberg and critical pumping rate approximations of seawater intrusion in coastal aquifers , 2011 .

[19]  S. P. Neuman,et al.  Applicability of Current Theories of Flow in Leaky Aquifers , 1969 .

[20]  D. A. Barry,et al.  Seawater intrusion processes, investigation and management: Recent advances and future challenges , 2013 .

[21]  Keith L. Bristow,et al.  Modelling seawater intrusion in the Burdekin Delta Irrigation Area, North Queensland, Australia , 2007 .

[22]  Philippe Renard,et al.  The problem of salt recycling and seawater intrusion in coastal irrigated plains: an example from the Kiti aquifer (Southern Cyprus) , 2004 .

[23]  J. Jiao,et al.  Seawater intrusion and coastal aquifer management in China: a review , 2014, Environmental Earth Sciences.