Determination of the Spatial Distribution in Hydraulic Conductivity Using Genetic AlgorithmOptimization

2016-12-16
Aksoy, Ayşegül
Lee, Jonghyun Harry
Kıtanıdıs, Peter K
Heterogeneity in hydraulic conductivity (K) impacts the transport and fate of contaminants in subsurface as well as design and operation of managed aquifer recharge (MAR) systems. Recently, improvements in computational resources and availability of big data through electrical resistivity tomography (ERT) and remote sensing have provided opportunities to better characterize the subsurface. Yet, there is need to improve prediction and evaluation methods in order to obtain information from field measurements for better field characterization. In this study, genetic algorithm optimization, which has been widely used in optimal aquifer remediation designs, was used to determine the spatial distribution of K. A hypothetical 2 km by 2 km aquifer was considered. A genetic algorithm library, PGAPack, was linked with a fast Fourier transform based random field generator as well as a groundwater flow and contaminant transport simulation model (BIO2D-KE). The objective of the optimization model was to minimize the total squared error between measured and predicted field values. It was assumed measured K values were available through ERT. Performance of genetic algorithm in predicting the distribution of K was tested for different cases. In the first one, it was assumed that observed K values were evaluated using the random field generator only as the forward model. In the second case, as well as K-values obtained through ERT, measured head values were incorporated into evaluation in which BIO2D-KE and random field generator were used as the forward models. Lastly, tracer concentrations were used as additional information in the optimization model. Initial results indicated enhanced performance when random field generator and BIO2D-KE are used in combination in predicting the spatial distribution in K.
Citation Formats
A. Aksoy, J. H. Lee, and P. K. Kıtanıdıs, “Determination of the Spatial Distribution in Hydraulic Conductivity Using Genetic AlgorithmOptimization,” presented at the AGU FALL MEETING , (12 - 16 Aralık 2016), San-Francisco, Amerika Birleşik Devletleri, 2016, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/82643.