Watershed Modeling: Isn't Hydrology Supposed to be the Simple Task?
Is the art of hydrology analysis taking a backseat to all the focus on 2D modeling advancements and the addition of Rain-On-Grid hydrology. It questions whether the allure of cutting-edge 2D modeling has diverted our focus from ensuring the accuracy of flow predictions.
In this presentation, we will look at how the hydrology component might not be as simple as you think, and more attention should be devoted to making sure the flows are correct before worrying about the hydraulic parameters. With lump parameter modeling, certain aspects of the runoff and routing process might get missed on the way to the outlet. Or while some parameters might have drastic changes locally, they might all get washed out as you move downstream in larger study areas. Also, with the abundance of stream flow, rainfall gauge, and radar-derived datasets, do these datasets simplify or complicate model validation?
Case examples will highlight some of the complexities and nuances of hydrology where model parameter adjustments aren’t as straightforward as presumed. Moreover, a comparative analysis between the traditional HEC-HMS model and the Rain-on-Grid 2D HEC-RAS model will be showcased, exploring their respective strengths and potential disparities. Ultimately, this presentation advocates for a renewed emphasis on grasping the foundational principles of hydrology to ensure dependable modeling outcomes.
Author Bio
Steve Godfrey is a modeling team leader with 30 years of experience in solving stormwater problems for local municipalities and state agencies across the country. He specializes in using hydrologic and hydraulic modeling for developing stormwater master plans, developing design alternatives to improve flood management, and working with near real time stream forecasting.
