Earth Sciences Division Staff: Xiaoyi Liu

Biographical Summary

My research focuses on heterogeneity characterization of subsurface media and quantification of the level and consequence of the associated uncertainty. A detailed subsurface characterization is crucial for accurate prediction of the dynamics of subsurface fluids such as water, contaminants, CO2, and brine, and a successful characterization relies on the effective use of measurement data from multiple physical processes as well as the use of advanced computing techniques and technologies such as large-scale optimization and High Performance Computing (HPC). When the characterization results are fed to management models such as a remediation optimization model or a CO2 injection optimization model, I am interested in not only the level of uncertainties (i.e., variance or higher moments) associated with the characterization, but the consequence of uncertainties for the management model. For the same characterization, the consequence varies with the management model; hence a context-specific measure of uncertainty is needed. However, traditional measures such as statistical moments are not context-specific and not suitable for this purpose.

Education

• PhD, Civil and Environmental Engineering , Stanford University - Sep 2007 – Jun 2011
• MS, Geoscience, University of Iowa - Aug 2004 – Dec 2006
• BS, Earth Sciences, Nanjing University, China -  Aug 1998 – Jul 2002

Professional Experience

Earth Science Division, Lawrence Berkeley National Laboratory - Jul 2011 - present

Postdoctoral Research Fellow

Geologic CO₂ storage in the deep subsurface such as depleted oil reservoirs, with focuses on

• effects of heterogeneity on the dynamics of CO₂ and brine in porous media;
• large-scale stochastic inverse modeling and leakage pathway detection for CO₂ storage sites;
• assimilation of multi-physics and multi-scale measurements for subsurface characterization; and
• effective uncertainty quantification and monitoring network optimization.

Environmental Fluid Mechanics & Hydrology, Stanford University - Sep 2007 – Jun 2011

Graduate Research Assistant

Conducted research on subsurface imaging, model calibration, remediation optimization and value of information in groundwater and environmental problems. More specifically, my research included:

• subsurface imaging and large-scale stochastic inverse modeling;
• parameter estimation for nonlinear environmental problems;
• cost-optimization of groundwater remediation under uncertainty;
• value of information in environmental remediation; and 
• environmental decision analysis.

Iowa Institute of Hydraulic Research, University of Iowa - Aug 2004 - Aug 2007

Graduate Research Assistant

Conducted research on subsurface imaging with validation, at lab scale (sandbox) and field scale (Mizunami Underground Research Site), with both hydraulic data (hydraulic tomography) and tracer data (partitioning/non-partitioning tracer tomography).

Research Projects

1. ESD Early Career Development Grant, $40K, 2012-2013, PI

Awards

• Chinese Government Award for Outstanding Students Abroad, China Scholarship Council, 2010 
• Outstanding Student Paper Award for 2005 Fall Meeting, AGU, 2006
• Renmin Scholarship, Nanjing University, two consecutive years, 2001-2002
• Bangheng Scholarship, Nanjing University, 2000
• China Merchants Bank Scholarship, Nanjing University, 1999

Memberships and Certificates

• Engineer-in-Training (EIT), National Council of Examiners for Engineering and Surveying (NCEES), 2011-
• American Geophysical Union (AGU), 2005-
• Society of Actuaries (SOA), 2007-