Stanford University - Xiaoyi Liu

⇒ Large Scale Inverse Modeling with Half A Million Unknowns

We show to the right our latest inverse modeling of hydraulic conductivity with 500,000 unknowns. The measurements are from eight laboratory pumping tests conducted in a sandbox of about 1.6 metre long, 0.8 metre high, and 0.1 metre thick. The whole simulation was finished in about 5 hours with one processor in use. The algorithm is based on maximum likelihood and flatness regularization, hence the tomogram (below) is the flattest solution that reproduces the data.

Sandbox 1 with a deterministic heterogeneous aquifer.

Inverted K field with a fine grid.


	⇒ Journal Papers Xiaoyi Liu, Yuan Liu, and Peter K. Kitanidis (2009), Large scale inverse modeling in hydraulic tomography, manuscript in preparation; Michael Cardiff, Xiaoyi Liu, Peter K. Kitanidis, Jack Parker, and Ungtae Kim (2009), Cost Optimization of DNAPL Source and Plume Remediation Under Uncertainty Using a Semi-Analytic Model, submitted manuscript; Xiaoyi Liu, Michael Cardiff, and Peter K. Kitanidis (2009), Parameter Estimation in Nonlinear Environmental Problems, submitted manuscript; Illman, W. A., X. Liu, S. Takeuchi, T.-C. J. Yeh, K. Ando, and H. Saegusa (2009), Hydraulic tomography in fractured granite: Mizunami Underground Research site, Japan, Water Resour. Res., 45, W01406, doi:10.1029/2007WR006715. times cited: 2; Illman, W. A., X. Liu, and A. J. Craig (2008), Evaluation of transient hydraulic tomography and common hydraulic characterization approaches through laboratory sandbox experiments, Journal of Environmental Engineering and Management, Vol. 18, No.4, pp. 249-256 . times cited: 0; Walter A. Illman, Andrew Craig, and Xiaoyi Liu (2008), Practical issues in imaging hydraulic conductivity through hydraulic tomography. Groud Water, 46,120-132. times cited: 8; Walter A. Illman, Xiaoyi Liu, and Andrew Craig (2007), Steady-state hydraulic tomography in a laboratory aquifer with deterministic heterogeneity: multi-method and multiscale validation of hydraulic conductivity tomograms. Journal of Hydrology, 341, 222-234, doi:10.1016/j.jhydrol.2007.05.011, times cited: 14; Liu, X., W. A. Illman, A. J. Craig, J. Zhu, and T.-C. J. Yeh (2007), Laboratory sandbox validation of transient hydraulic tomography, Water Resour. Res., 43, W05404, doi:10.1029/2006WR005144, times cited: 15;
	⇒ Conference Presentations Liu, Xiaoyi, M. Cardiff, J. Parker, P. Kitanidis, NAPL remediation cost optimization under uncertainty using a semi-analytic model, AGU Fall meeting 2008, poster Illman, W. A., X. Liu, S. Takeuchi, T.-C. J. Yeh, K. Ando, and H. saegusa, Hydraulic Tomography in Fractured Granite: The Mizunami Underground Research Laboratory Site, Japan, AGU Fall 2007 meeting 2007 H11-I, speak; Xiaoyi Liu, Walter A. Illman, and Andrew J. Craig, Hydraulic and tracer tomography for the characterization of DNAPL source zones: A laboratory sandbox study,AGU Joint Assembly 2007, speak; Illman, W. A., A. Craig, X. Liu, A. Massi, T.-C. J. Yeh, D. Yin, and J. Zhu, A new paradigm in DNAPL source zone characterization: 3D imaging of contaminant distributions through hydraulic and tracer tomography, AGU Joint Assembly 2007, invited speak; Yin, D., W. A. Illman, X.Liu, and A. J. Craig, Hydraulic tomography using temporal moments of drawdown-recovery data: Laboratory sandbox study,AGU Joint Assembly 2007, speak; Walter A. Illman, Xiaoyi Liu, and Andrew J. Craig, Steady-State Hydraulic Tomography in a Laboratory Sandbox Aquifer: The Role of Signal-to-Noise Ratio and Conditioning on K Tomograms, EGU 2007, speak; Walter A. Illman, Xiaoyi Liu, and Andrew J. Craig, Multi-method and multiscale validation of hydraulic tomography in a laboratory aquifer with deterministic heterogeneity, Society fir Industrial and Applied Mathematics (SIAM) Conference on Mathematical & Computational Issues in Geoscience , March 19-22, 2007, Santa Fe, NM, invited speak; Massi, X. Liu, T.-C. J. Yeh, J. Zhu, DNAPL source zone characterization by the fusion of hydraulic and tracer tomography : Experimental and modeling studies , SERDP & ESTCP -Partners in Environmental Technology Technical Symposium & Workshop, November 28 - 30, 2006, Washington DC, poster; Xiaoyi Liu, Walter A. Illman, and Andrew J. Craig, Transient hydraulic tomography in a laboratory sandbox aquifer: Multi-method and multiscale validation of hydraulic conductivity and specific storage tomograms, AGU WPGM 2006, speak; Danting Yin, Walter A. Illman, Xiaoyi Liu, and Andrew J. Craig, Laboratory sandbox validation of hydraulic tomography using temporal moments of drawdown recovery data, AGU WPGM 2006, poster; Illman, W. A., A. Craig, X. Liu, and D. Yin, Lessons learned from hydraulic tomography in a laboratory aquifer with deterministic heterogeneity, Hydraulic Tomography Workshop held at Boise State University, Boise, Idaho, 6/8 - 6/9/2006, invited speak; Xiaoyi, Walter A. Illman, and Andrew J. Craig, Transient hydraulic tomography in a sandbox with deterministic heterogeneity: Validation of hydraulic conductivity and specific storage tomograms. AGU Fall Meeting 2005, poster; Walter A. Illman, Xiaoyi Liu, and Andrew J. Craig, Steady-state hydraulic tomography in a laboratory aquifer with deterministic heterogeneity: Multiscale validation of hydraulic conductivity tomograms. AGU Fall Meeting 2005, invited speak; Andrew J. Craig, Walter A. Illman, and Xiaoyi Liu, A Cyclic Sediment Transport Approach to Create a Synthetic Aquifer with Multiscale Heterogeneity.AGU Fall Meeting 2005, poster;