Siyuan Xian

Civil & Environmental Engineering (CEE) PhD 2018

Siyuan (Henry) Xian received a Ph.D. degree in the Department of Civil and Environmental Engineering (CEE) from Princeton University in May 2018 and is a Ford Fellow in the Woodrow Wilson School of International and Public Affairs’s PEI-STEP Fellowship program. He is also a visiting research fellow at the Wharton Risk Center of the Wharton School. He received a master's degree from Princeton University in May 2015 and a bachelor's degree in civil engineering with first class honors from the University of Hong Kong in June 2013. During his college years, Henry conducted research at multiple academic institutions, including Imperial College London, University of California, Berkeley and University of California, Davis. He received many awards over the years from Princeton, including a Princeton University Fellowship, PEI-STEP Fellowship, Mary and Randall Hack '69 Graduate Award, Norman J. Sollenberger Fellowship and travel awards from the Society for Risk Analysis. Henry has been invited to speak at many international conferences and institutions, including Society for Risk Analysis (SRA)’s annual meetings (2015-2017), Princeton University, The Wharton School, Duke University, Carnegie Mellon University, University of Delaware, University of Hong Kong, Wuhan University, and East China Normal University.

Henry's research addresses the important topic of flood risk management and coastal resilience for both communities and mega-cities. His goal is to integrate advanced science and engineering to develop coastal risk mitigation strategies, accounting for potential effects of climate change and considering economical feasibility, social equality, and human behavior in decision-making.  Henry's research uses a number of new analytical methods to improve decision support for coastal resilience.  It integrates multiple elements of the physical and social science dimensions of coastal vulnerability and protection, addressing hurricane frequency and intensity, structural damage from storm surge, potential effects of climate change, and public risk perception and mitigation behavior, including the design of insurance programs that provide both efficiency and equity in community risk-sharing.   Many of the methods used in Henry's research apply tools and insights from risk analysis, urban planning, extreme weather analysis, and climate change adaptation and mitigation.

His research can be summarized into three groups: damage analysis, risk mitigation, and risk perception and decision-making. The damage analysis is based on damage survey data from Hurricane Sandy in 2012 and Hurricane Irma in 2017. In addition to analyzing structural vulnerability and economic losses, the study also compared the observed damage to FEMA flood maps and found that FEMA was not always accurate in depicting the special variation of the risk.  In addition to house-level risk mitigation, the study also investigated options for large-scale coastal protections (e.g., levees designed based return periods vs. static optimal analysis vs. dynamic optimal analysis) and explored the optimal design that can save the long-term lifecycle costs and reduce the extreme risk to an acceptable level. Beyond engineering measures, the study investigated the public’s risk perception, voluntary flood insurance purchase behavior and public support for flood adaptation policy, based on a large survey database. A more recent study used machine learning tools to develop models that apply to hurricane risk and loss projections, as well as better predict human behavior in flood risk management.

In Henry's STEP-PEI project, he examined the government’s decision-making related to flood protection, and compared the cases of New York City and Shanghai. He also provided a unique framework for integrating natural and social sciences, which is a very important approach to solving the complex problem of coastal flood resilience in the context of climate change.


Xian, S., Lin, N. and Hatzikyriakou, A (2015) Storm Surge Damage to Residential Areas: A Quantitative Analysis for Hurricane Sandy in Comparison with FEMA Flood Map. Natural Hazards, 79(3): 1867-1888. doi:10.1007/s11069-015-1937-x.

Hatzikyriakou, A., Lin, N., Gong, J., Xian, S., Hu, X. and Kennedy, A (2015) Component-based vulnerability analysis for residential structures subjected to storm surge impact from Hurricane Sandy. Natural Hazards Review (ASCE), 17(1): 1-15. doi/abs/10.1061/(ASCE)NH.1527-6996.0000205.

Shao, W., Xian, S.*, Keim, B., Goidel, K. and Lin, N (2017). Understanding perceptions of changing hurricane strength along the US Gulf Coast. International Journal of Climatology. 37 (4): 1716-1727.

Shao, W., Xian, S.* #, Lin, N, Kunreuther, H, Jackson, N., and Goidel, K (2017). Understanding the effects of past flood events and perceived and estimated flood risks on individuals' voluntary flood insurance purchase behavior. Water Research. 108: 391-400.

Xian, S.*, Lin, N. and Kunreuther, H (2017). Optimal house elevation for reducing flood-related losses. Journal of Hydrology. 548: 63-74.

Xian, S.*, Shao, W., Lin, N., Small, M. (2017). A sequential model to link contextual risk, perception and public support for flood adaptation policy. Water Research.

Xian, S., Yin, J., Lin, N., and Oppenheimer, M (2018). Influence of risk factors and past events on flood resilience in coastal megacities: comparative analysis of NYC and Shanghai. Science of the Total Environment. 610: 1251-1261.

Shao, W., Gardezi, M., and Xian, S. . Annals of the American Association of Geographers. doi/abs/10.1080/24694452.2018.1426436

Shao, W. and Xian, S. (2017). After Harvey, many Texans will think differently about hurricane risks. The Conversation. (top academic media platform)

Shao, W. and Xian, S. (2017). The irrational way people calculate hurricane risks.

Contact Information:

Hurricane Hazards and Risk Analysis Research Group