Building the Trinity River Delta Hydrodynamic Model

The Trinity River Delta Hydrodynamic Model (TDHM) has been constructed under a contract with the Texas Water Development Board based on prior work with the Nueces Delta Hydrodynamic Model (NDHM) and a new Fine Resolution Environmental Hydrodynamics Model written in C (FrehdC). The model has been designed to run at practical grid scales from 10x10 m to 50x50 m using new approaches to handling the subgrid features that are known at the 1x1 m lidar scale but cannot be directly represented in the governing flow equations. Details of the FrehdC model are presented in secion 2. Numerical discretization for the new approach to handling subgrid data (contract Task 2) is presented in section 3. The operational sensitivity of the TDHM model results to perturbation of the boundary conditions (contract Task 1) is discussed in section 4. The sensitivity analyses are used to recommend sensor locations for a future field study for model validation. Methods for a coupled surface-groundwater version of TDHM (contract Task 3) are presented in section 5. Appendices provide further details in the form of pre-publication copies of peer-reviewed journal papers written in the course of this study.