Background

The purpose of this page is to describe the validation and verification testing undertaken by HEC staff to ensure proper functioning of the HEC-FDA Version 2.1 (beta) software and to compare and explain results where they differ from Version 2.0.2. 

Case Study Models

For this effort, nine case study models were utilized for V&V testing consistent with previous version releases. A base year, without-project condition was modeled for each case study and results were recorded for Version 2.0.2 and Version 2.1 to compare expected annual damage (EAD) and performance results. These models were also utilized to ensure functional forward migration of studies. 

Additional modeling was conducted and recorded for Version 2.1 for future and with-project conditions. These results were utilized to confirm equivalent annual damage (EqAD) results against an independent spreadsheet model, confirm damages reduced calculations, ensure proper functioning of with-project inputs, and to ensure general proper functioning of the standard user interface (UI).

The table below describes the input components of each model. 


ModelHydraulic Data TypeTerrain Data TypeGround Elevations SourceFrequency Function

Glendive

GriddedN/AInventoryStage-Only
GreenbrookUnsteadyN/AInventoryStage-Only
London OrleansGriddedN/AInventoryStage-Only
MuncieGriddedHDFTerrainAnalytical Flow

North DeSoto

GriddedN/AInventoryStage-Only
River Des PeresGriddedTIFTerrainStage-Only
TafunaGriddedTIFTerrainGraphical Flow
WatertownGriddedTIFTerrainGraphical Flow
West SacramentoUnsteadyN/AInventoryAnalytical Flow

Results

Equivalent Annual Damages

Equivalent annual damages (EqAD) results in version 2.1 were compared to an independent spreadsheet model. Results in version 2.1 were exactly equal to the results in the spreadsheet model. The spreadsheet model and EqAD results from version 2.1 are included at the shared drive location listed below.

Performance

Annual exceedance probability (AEP) performance results in version 2.1 were compared to version 2.0.2. Results are shown below for the base-year, without-project condition. More detailed results are available at the shared drive location listed below.

GlendiveThreshold ValueMeanMedian1030500.10.040.020.010.0040.002
2.0.213.650.03490.03250.29880.65520.83050.99690.62930.25850.10840.02980.0164
2.113.650.03510.03250.30010.65720.83210.99690.64950.26010.10980.02990.0167
Difference00.000200.00130.0020.001600.02020.00160.00141E-040.0003
GreenbrookThreshold ValueMeanMedian1030500.10.040.020.010.0040.002
2.0.2100.110.9990.9991111000000
2.1100.580.9991111000000
Difference0.4700.0009000000000
London OrleansThreshold ValueMeanMedian1030500.10.040.020.010.0040.002
2.0.25.820.17160.17280.84780.99650.99990.07340.020.01910.01480.00270.0009
2.15.820.1771780.1728320.85770.99710.99990.0750.00470.00480.00470.00270.0009
Difference00.0055783.2E-050.00990.000600.0016-0.0153-0.0143-0.010100
Muncie (IA1)Threshold ValueMeanMedian1030500.10.040.020.010.0040.002
2.0.2945.780.05370.04960.42430.80920.93670.90220.39060.16630.08450.04680.0338
2.1945.780.05390.04970.42510.810.93720.90030.38790.16620.08370.04430.0325
Difference00.00020.00010.00080.00080.0005-0.0019-0.0027-0.0001-0.0008-0.0025-0.0013
North DeSotoThreshold ValueMeanMedian1030500.10.040.020.010.0040.002
2.0.29.120.54180.54330.9996110.00010.00010.0001000
2.19.120.54470.54330.999611000000
Difference00.00290000-0.0001-0.0001-0.0001000
River Des PeresThreshold ValueMeanMedian1030500.10.040.020.010.0040.002
2.0.2543.710.31910.3320.9786110.007700000
2.1543.710.33020.3320.9818110.005900000
Difference00.011100.003200-0.001800000
TafunaThreshold ValueMeanMedian1030500.10.040.020.010.0040.002
2.0.242.330.46270.51190.998110.000100000
2.142.330.53380.51170.9995110.000100000
Difference00.0711-0.00020.001500000000
WatertownThreshold ValueMeanMedian1030500.10.040.020.010.0040.002
2.0.21704.730.03780.03450.31990.68550.85450.98770.58460.25740.07480.03040.0108
2.11704.730.03760.03450.31810.68290.85260.98770.58450.25770.07460.03010.0107
Difference0-0.00020-0.0018-0.0026-0.00190-1E-040.0003-0.0002-0.0003-0.0001
West SacramentoThreshold ValueMeanMedian1030500.10.040.020.010.0040.002
2.0.221.510.71740.7237111000000
2.121.510.71740.7237111000000
Difference000000000000

Expected Annual Damages

Most of the results show negligible change in EAD. Tafuna demonstrates relatively larger change in EAD due to changes in how uncertainty is estimated for graphical flow frequency functions. Specifically, in Impact Area 11, the upper bound on flow uncertainty for a given frequency decreases by several thousand CFS for many frequencies between .5 AEP and .02 AEP, meaning the flows sampled in the flow-frequency function are significantly lower in version 2.1 relative to version 2.0.2, which will correspond to significantly lower stages and damage values.

The table below shows results by case study broken down by damage category and software version. More detailed results are available at the shared drive location listed below.

Study NameDamage Category Version 2.0.2 Mean EAD Version 2.1 Mean EADPercent Change
GlendiveRES$231.28$225.6-2.46%

COM$1,084.65$1,067.6-1.57%

Total$1,315.92$1,293.27-1.72%
GreenbrookRES $50,336.46

$50,135.10

-0.40%

IND$12,267.77$12,199.33-0.56%

COM$14,836.33$14,747.31-0.60%

UTL$13.59$13.05-3.97%

APT$16,301.84$16,340.110.23%

MUN$3,830.87$3,867.560.96%

Total$97,586.86$97,302.46-0.29%
London OrleansCOM$9,659.69$9,651.11-0.09%

IND$2,378.43$2,368.5-0.42%

PUBL$1,292.98$1,292.26-0.06%

RES$34,832.81$34,734.13-0.28%

Total$48,163.91$48,046.00-0.24%
Muncie (IA1)RES$391,451.82$392,574.710.29%

IND$46,956.59$47,135.290.38%

COM$83,706.71$84,054.130.42%

PUB$397,351.69$398,732.800.35%

Total$919,466.80$922,496.90.33%
North DeSotoResidential$704.80$704.08-0.10%

Commercial$2,598.89$2,599.340.02%

Industrial$138.50$137.55-0.69%

Public$35.16$34.77-1.11%

Agricultural$1.27$1.19-6.30%

Total$3,478.63$3,476.93-0.05%
River Des PeresCOM$2,593.88$2,574.41-0.75%

PUB$438.97$439.550.13%

RES$4,013.10$4,008.18-0.12%

IND$181.51$179.53-1.09%

Total$7,227.46$7,201.67-0.36%
Tafuna (IA11)IND$112.02$93.38-16.64%

RES$21.95$6.58-70.02%

Total$133.97$99.95
-25.39%
WatertownRES$2,479.82$2,518.591.56%

COM$2,263.48$2,305.261.85%

IND$874.71$890.451.80%

PUB$108.61$111.452.61%

Total$5,726.62$5,825.741.73%
West SacramentoRES$189,002.06$189,002.060.00%

COM$1,001,089.69$1,001,089.690.00%

IND$430,818.36$430,818.420.00%

PUB$22,620.99$22,621.000.00%

Total$1,643,531.10$1,643,531.100.00%

Life Safety Risk

Due to a lack of prior modeling and lack of available case studies, a single case study for life safety risk was utilized to test the UI for functionality and for reasonable results. That case study, Alaiwai, is provided among the supporting data at the shared drive location provided below.

Supporting Documentation and Data

The supporting models and detailed results tables can be found at this shared drive location. The EqAD spreadsheet calculator used to independently verify EqAD results is also located in the folder. 

The release notes can be found here.

HEC-FDA Version 2.1 (beta) can be found here. Download the portable package to a location where you have write access, such as C:\Programs and extract the contents of the zip file. Open the HEC-FDA 2.0 folder that contains the extracted contents to find the .exe application HEC.FDA.View with the green house icon. Double-click on HEC.FDA.View to launch the software.