A. W. Jayawardena, a retired professor with over 40 years of experience in the fields of hydrology, water resources and environmental engineering in academia, government, consulting engineers and international organizations, obtained his B.Sc. (Eng) Hons degree from the University of Ceylon (now Sri Lanka), and post-graduate degrees M.Eng. from the University of Tokyo, M.S. from the University of California at Berkeley, and Ph.D. from the University of London. He is a Chartered Engineer, a Fellow of the UK Institution of Civil Engineers, a Fellow of the Hong Kong Institution of Engineers and a Life Member of the American Society of Civil Engineers.. At present, he is an Adjunct Professor in the Department of Civil Engineering of the University of Hong Kong where he has been teaching for many years, and has in the past been a Technical Advisor to the Research and Development Centre of Nippon Koei Co. Ltd (Consulting Engineers), Japan, Research and Training Advisor to the International Centre for Water Hazard and Risk Management (ICHARM) under the auspices of UNESCO, Japan, and concurrently a Professor in the National Graduate Institute for Policy Studies (GRIPS), Japan, Guest Professor of Beijing Normal University, China, Visiting Professor of Hohai University, China, Honorary Professor in the Department of Statistics and Actuarial Sciences of the University of Hong Kong and a Visiting Professor in Tsinghua University of China. He has been the recepient of the 2013 International Award of the Japan Society of Hydrology and Water Resources, has authored the book Environmental and Hydrological Systems Modelling, and authored or co-authored over 175 reseach publications