1. US Army Corps of Engineers ® Engineer Research and Development Center 1 Background: High-resolution modeling t = 0.50 s t = 1.0 s t = 2.5 st = 4.5 s Two-phase Navier-Stokes models for breaking waves and accurate predictions of forces on objects (cm scale resolution)

2. US Army Corps of Engineers ® Engineer Research and Development Center 2 A Typical Simulation for IED Detection Desert road Domain is 30m x 30m x 1m 24.5M tetrahedral soil elements ~5M triangular vegetation elements Full simulation is 336 processors Runs about 1/8 real time

3. US Army Corps of Engineers ® Engineer Research and Development Center 3 Timeline of Mesh Sizes 200520062007200820092010 100 m 2 1200 m 2 6 m 2 1 m 2 Domain Size Trends –FY05~1 m 2 –FY06~10 m 2 –FY07~100 m 2 –FY08~1000 m 2 –FY09~1600 m 2 –FY10 ~3000 m 2 1600 m 2 900 m 2

4. US Army Corps of Engineers ® Engineer Research and Development Center 4 High-resolution isn’t everything Model Domain: 7632 mi 2 River Length (main stem): 245 mi Mesh (2D 0.3 M, 3D 7 M) CREST (from http://eos.ou.edu) Highly-resolved simulations are computationally and data intensive

5. US Army Corps of Engineers ® Engineer Research and Development Center 5 Transitioning scales: Downscaling parameters From Hendrickx, Pradhan, et al. SEBAL derived IC (a), GSSHA with constant ICs (b-e), GSSHA with SEBAL IC (f)

6. US Army Corps of Engineers ® Engineer Research and Development Center 6 Distributed runoff/routing Diffusive Wave 2D Shallow-Water Variable Infiltration Curve 1D-v Richards’ 2D groundwater 3D-Richards’ Two-phase subsurface flow 3D Shallow Water Two-phase Navier- Stokes complexity A step towards operational multi- resolution, multi-scale hydrology Information propagates down Coarsen physical model with spatial scale Couple models across scales More rigorous upscaled and reduced order models from fine scale 2015?