Modeling Distributed and Point Sources in a GWCE-Based Finite Element Hydrodynamic Model, ADCIRC

Abstract:

During tropical storms, rainfall and inland riverine flows can lead to a significant amount of flooding, both in the upland and coastal areas. Over the last several years, a coupled model system, called ASGS-STORM (ADCIRC Surge Guidance System-Scalable, Terrestrial, Ocean, River, Meteorology), has been developed to provide total water levels, which includes tides, waves, surge, and runoff. Currently, this system couples precipitation estimates, a hydrologic model, a hydrodynamic model and a wave model. In the upland areas of the domain, the hydrologic model is utilized to simulate the rainfall-runoff process during an event; however, in the current system, the precipitation occurring over the “wet” coastal areas are not captured by the hydrodynamic model. In this presentation, we will discuss the development and application of a source term that has been incorporated into the ADCIRC (hydrodynamic) model. The flexible implementation allows the user to simulate distributed (e.g., rainfall) or point (e.g., sub-grid scale tributary or lateral inflow) sources. This distributed source term is first evaluated under several idealized testcase for mass conservation and spatial/temporal accuracy. Next, the point source application, which is used to represent lateral inflow or sub-grid scale tributary flow without having to incorporate extensive refinement to the hydrodynamic model grid (i.e., to add small channels to route water from dry areas in ADCIRC into the riverine areas via hydrologic modeling within ADCIRC), is tested in an idealized setting. Lastly, we will show some results utilizing Hurricane Irene in the North Carolina area or Delaware Bay area.