Dr. Zhang is a Research Professor of Civil and Environmental Engineering and Adjunct Professor of Geography at Portland State University and a Senior Scientist at LimnoTech. He has been working side-by-side with the Corps of Engineers team for the development of contaminant, water quality and vegetation modeling capabilities. He is the primary author of a set of water quality modules that are currently coupled with HEC-RAS, HEC-ResSim, and AdH hydraulic models as a companion water quality model. He is a co-developer of the HEC-RAS riparian vegetation module and a contributor of 2D reservoir hydrodynamic and water quality CE-QUAL-W2 model. He has conducted a wide range of hydraulic and water quality modeling applications for many of the major US river systems including the Columbia and Snake River system, Lehigh River system, Jacksonville Harbor-St. John River, Minnesota River, Missouri River, and Mississippi River. Additionally, He has developed and lectured at water quality modeling workshops and short courses. He has been an active participant in professional organizations and served on several committees for ASABE, ASCE, and AWRA, and WEF.