ASCE has honored Vijay Singh, D.Sc., P.E., Hon.D.WRE, F.EWRI, Dist.M.ASCE, and Solomon Vimal, Ph.D., S.M.ASCE, with the 2023 Norman Medal for their paper “A Unified Framework for Governing Equations of Hydrologic Flows,” Journal of Hydrologic Engineering, January 2022.  

The authors start from a fundamental premise that physics-based models are derived from laws of conservation of mass, momentum, and energy. These are supplemented by constitutive laws to represent material behavior. Depending on the constituent of interest (e.g., water, chemicals, bacteria, viruses), governing equations are derived and solved to aid with problems of detection, identification, prediction, forecasting, simulation, and others. The same overall methodology is applied to many hydrologic problems such as surface flows, infiltration, saturated and unsaturated subsurface flows, flow through ice, and in domains outside hydrology such as traffic flow, electrical circuits, etc. While different domains have then gone on to rederive equations in their respective fields, what has been lacking is a unifying framework that would pull all these equations under a single umbrella. This would not only aid in succinct representation but would greatly aid the development of governing equations in different areas without having to “reinvent the wheel.” 

Further, such a unifying framework would point to what kind of scaling behavior would be expected from different constituents. The authors then demonstrate the viability of this unified approach to different classes of problems, and point to the advantages of such an approach in various applications, including engineering education, research and design; method of numerical solution; and physical interpretation.

The Norman Medal is bestowed upon the author or authors of a paper that is judged worthy of special commendation for its merit as a contribution to engineering science.