Coastal Aquifer Management Based on the Joint use of Density-Dependent and Sharp Interface Models
- 314 Downloads
In pumping optimization of coastal aquifers, the evaluation of the objective function and constraints using density-dependent models is overwhelmed by complex and time-consuming numerical simulations. To address those cases where the available density-dependent model runs are very limited, due to excessive computational burden, an efficient optimization strategy is developed. The proposed methodology uses an efficient sharp interface model jointly with a complex density-dependent model in an evolutionary optimization algorithm. While most evaluations are based on the sharp interface model, the density-dependent model is selectively called to evaluate promising solutions and to improve the predictions of the sharp interface model through the adaptive modification of the saltwater-freshwater density ratio. The method is tested for pumping optimization problems in confined and unconfined coastal aquifers with multiple pumping wells. The optimal solutions are compared to those obtained by density-dependent as well as by sharp interface optimization alone. Under a very restrictive computational budget, the best feasible solution is attained in less than 25 density-dependent model runs for two optimization problems of 10 and 20 decision variables. The results indicate that this optimization method leads to good feasible solutions and that an improved estimation of optimal pumping rates can be achieved within a limited computational budget. The method could also stand as an efficient preliminary exploration of the optimal search space, to provide good feasible starting points for the implementation of more comprehensive methods of coastal aquifer management.
KeywordsSharp interface models Density-dependent models Pumping optimization Computational budget
Compliance with ethical standards
The authors declare that the present manuscript has not been submitted to more than one journal for simultaneous consideration and it has not been published previously.
Conflict of interest
The authors would like to declare that they have no conflict of interest.
- Bear J, Verruijt A (1987) Modeling groundwater flow and pollution (Vol. 2). Springer Science & Business MediaGoogle Scholar
- Cheng AH-D, Ouazar D (1999) Analytical solutions. In: Bear J, Cheng AH-D, Sorek S, Ouazar D, Herrera I (eds) Seawater intrusion in coastal aquifers—concepts, methods and practices. Kluwer Academic Publishers, DordrechtGoogle Scholar
- Christelis V, Mantoglou A (2013) improved sharp interface models in coastal aquifers of finite dimensions. In EGU general assembly conference abstracts vol. 15. p 12228Google Scholar
- Christelis V, Mantoglou A (2015) Pumping optimization of coastal aquifers using radial basis function metamodels. Proceedings of the 9th World Congress of EWRA ‘Water Resources Management in a Changing World: Challenges and Opportunities’ 10–13 June 2015, Istanbul, TurkeyGoogle Scholar
- Christelis V, Kopsiaftis G, Mantoglou A (2012) Coastal aquifer management under drought conditions considering aquifer spatial variability. IAHS-AISH publication 293–297Google Scholar
- Dausman A, Langevin C, Bakker M, Schaars F (2010) A comparison between SWI and SEAWAT—the importance of dispersion, inversion and vertical anisotropy. 21st Salt Water Intrusion Meeting, Gov. of Azores, AzoresGoogle Scholar
- Efstratiadis A, Koutsoyiannis D (2002) An evolutionary annealing-simplex algorithm for global optimization of water resource systems. Proceedings of the Fifth International Conference on Hydroinformatics, Cardiff, UK, International Water Association Publishing 2:1423–1428Google Scholar
- Efstratiadis A, Nalbantis I, Koutsoyiannis D (2014) Hydrological modeling of temporally-varying catchments: facets of change and the value of information. Hydrol Sci J 60(7–8):1438–1461Google Scholar
- Mathworks (2010) MATLAB global optimization toolboxGoogle Scholar
- Nocedal J, Wright SJ (2006) Numerical optimization, Second Edition. Springer series in operations research, Springer VerlagGoogle Scholar
- Therrien R, McLaren RG, Sudicky EA, Panday SM (2006) HydroGeoSphere-A three-dimensional numerical model describing fully-integrated subsurface and surface flow and solute transport. Groundwater Simulations Group, University of Waterloo, Canada, draft ed. 2006Google Scholar