HEC-RAS 6.6 previous release
HEC-RAS 6.6, the release before 7.0, run the same way (1D, and 2D with its default SWE-ELM): kept so a change between versions shows.
Scored for compatibility with the current release, not for physics. Ran 8 tests; worked examples and previous releases are shown beside the leaderboard, not ranked on it. Score cards from: HEC-RAS 6.6, HEC-RAS 6.6 2D SWE-ELM.
| Test | Difference, rank | Checks |
|---|---|---|
| Gentle backwater in a channel A1F-001 | #5= 0.011 % off of 15 models | • Average depth error 0.1 mm off; · Water conserved 0.011 % error HEC-RAS stores input elevations to the nearest 0.001 ft (0.3 mm), even in a metric project. The depth error therefore stops at about 0.1 mm on every grid and cannot shrink with the grid, so its convergence rate says nothing about the scheme. |
| Dam break onto dry ground A1F-010 | #14= 26 % off of 20 models | • Flood front 97.4 m behind exact; · Water conserved 0.0049 % error The flood advances as a steep bore and its front is 97 m behind the exact one; the error does not fall on finer grids. HEC-RAS 2D was built and run with no GUI step; the dam-break step was carried in by a restart file. |
| Dam break into shallow water A1F-011 | #10= 0.9 % off of 20 models | • Average depth error 5 mm off; · Water conserved 0.011 % error The bore is in about the right place (depth error 5 mm), but the error does not fall on finer grids. |
| Steady flow over a shaped bed A2A-010 | #3= 0.01 % off of 12 models | • Average depth error 0.094 mm off; · Water conserved 0.0096 % error Very accurate (0.09 mm), but the error stops falling below about 0.1 mm on finer grids (0.54, 0.16, 0.12, 0.09 mm), so its convergence rate's range is wide (0.11 to 1.50). HEC-RAS stops iterating at its default water-surface tolerance (0.01), which is the likely floor. |
| Flooding a cut-off pond A2C-EA1 | #7= 5.1 % off of 10 models | • Pond level, point 1 1.3 cm off; • Pond level, point 2 1.3 cm off; • Peak level 0.052 mm off Run on the EA's own 2 m DEM, which HEC-RAS uses as sub-grid terrain. The pond settles 1.3 cm above the sill. |
| Filling floodplain hollows A2C-EA2 | #7= 0.77 % off of 10 models | • Water conserved 0.77 % off HEC-RAS's own volume accounting reports 1.4 % more water stored than flowed in (98,576 m³ from 97,194 m³). Integrating its water levels over the 2 m DEM gives +0.76 %. Run on the EA's own 2 m DEM as sub-grid terrain. |
| Flood spreading over a floodplain A2C-EA4 | #1= under 0.01 % off of 10 models | • Water conserved 0.00088 % off |
| Valley flooding A2C-EA5 | #7= 0.041 % off of 10 models | • Water conserved 0.041 % off |