Multiple objective management strategies for coastal aqifers utilizing new surrogate models
Journal Publication ResearchOnline@JCUAbstract
Coastal aquifers are hydraulically connected to the sea and therefore susceptible to saltwater intrusion problems. This study proposes the utilization of a new surrogate model within coupled simulation-optimization (S/O) model for the management of coastal aquifers subjected to density-dependent saltwater intrusion processes. The simulation of the transient 3-dimensional density-dependent flow and transport model is based on the solution of an implemented numerical simulation model. Direct coupling of the numerical simulation model into the multi-objective genetic algorithm (MOGA) is computationally expensive. Hence, the solution of the numerical simulation model with random input variables are used to train and test the support vector machine regression (SVMR) surrogate models for approximately simulating the flow and transport processes. The performances of the new surrogate models are evaluated using various performance evaluation criteria. The resulting validated SVMR surrogate models are coupled to the MOGA and implemented for an illustrative coastal aquifer with an aim to develop efficient coastal aquifer management strategies. Based on the objective functions, execution of S/O model presented a set of optimal groundwater withdrawal rates from the simulated aquifer. It also ensured salinity levels at the designated monitoring wells are constrained within specified limits. The efficiency of the new SVMR surrogate models is also demonstrated. Evaluation results suggested that the projected S/O model is an effective way of developing feasible and reliable coastal aquifer management strategies. It also enhances the possibility of solving more realistic large-scale problems and developing regional-scale coastal aquifer management methodologies.
Journal
International Journal of Geomate
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Volume
15
ISBN/ISSN
2186-2990
Edition
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Issue
48
Pages Count
7
Location
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Publisher
GEOMATE International Society
Publisher Url
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Publisher Location
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Publish Date
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Url
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Date
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EISSN
N/A
DOI
10.21660/2018.48.7169