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BENCHMARKING 2D MODELS - HEC-RAS 5.0 versus INFOWORKS ICM

September 3rd, 2015 – Presented to TFMA Fall Technical Summit

By:Tom Davies, PE; Hydraulics Group Lead - North Texas Water ResourcesMayank Mehta, PE; Hydraulic Engineer - North Texas Water Resources

Why 2D?

2

UK Environment Agency benchmarking of 2D Software Packages

• Benchmark 2010 – 14 packages

• Benchmark 2013– 19 packages

4

Test 1: Flooding a disconnect water body

5

Test 2: Filling of floodplain depressions

Test 3: Momentum conservation over a small obstruction

Test 4: Speed of flood propagation over an extended floodplain

Test 5: Valley floodingTest 6: DambreakTest 7: River and floodplain linkingTest 8: Surface flow from a surcharging sewer in urban areas

Test 1: Flooding a disconnect water body

6

Profile of digital elevation model used in Test 1

Test 1/8

Test 1 – HEC-RAS – water filling up

7

Test 1/8

Test 1 – HEC-RAS – water receding

8

Test 1/8

Test 1 – InfoWorks ICM

9

Test 1/8

10

Profile of digital elevation model used in Test 1

Test 1/8Water Level at Point 1

Water Level at Point 1

11

100

9.9

9.95

10

10.05

10.1

10.15

10.2

10.25

10.3

10.35

10.4

0 2 4 6 8 10 12 14 16 18 20

Test 1/8

12

Test 2: Filling of floodplain depressionsTest 2/8

13

Test 2/8

Test 2 – InfoWorks ICM

14

Test 2/8

Water Level at Point 4

15

9.2

9.3

9.4

9.5

9.6

9.7

9.8

0 5 10 15 20

S

Test 2/8

Water Level at Point 5

16

7.9

8

8.1

8.2

8.3

8.4

8.5

0 5 10 15 20 25 30 35 40 45

Test 2/8

Test 3: Momentum conservation over a small obstruction

17

Test 3/8

Test 3 – HEC-RAS

18

Test 3/8

Test 3 – InfoWorks ICM

19

Test 3/8

20

Test 3/8

Water Level at Point 1

Water Level at Point 1

21

9.7

9.75

9.8

9.85

9.9

9.95

10

10.05

10.1

10.15

0.00 100.00 200.00 300.00 400.00 500.00 600.00

Series1

Test 3/8

Test 4: Speed of flood propagation over an extended floodplain

22

Test 4/8

Test 4 – HEC-RAS

23

Test 4/8

Test 4 – InfoWorks ICM

24

Test 4/8

25

Test 4/8Water level at Point 3

Water level at Point 3

26

0

0.1

0.2

0.3

0.4

0.5

0 50 100 150 200 250 300

Series1

Test 4/8

Test 5: Valley flooding

27

Test 5/8

Test 5 – HEC-RAS

28

Test 5/8

Test 5 – InfoWorks ICM

29

Test 5/8

30

Test 5/8Water Level at Point 3

Water Level at Point 3

31150

151

152

153

154

155

156

157

158

159

0 2 4 6 8 10 12 14 16 18 20

Test 5/8

Velocity at Point 3

32

0

0.5

1

1.5

2

2.5

3

3.5

0.5 1 1.5 2

Test 5/8

Test 6: Dambreak

33

Test 6/8

Test 6 – HEC-RAS

34

Test 6/8

Breach in HEC-RAS

35

Test 6/8

Test 6 – InfoWorks ICM

36

Test 6/8

Test 6 – HEC-RAS – Velocity – Momentum Equation

37

Test 6/8

Test 6 – HEC-RAS – Velocity – Diffusion Equation

38

Test 6/8

Hydraulic Jump – erosion protection

1. Before Dam break or spill over

39

Test 6/8

Hydraulic Jump – erosion protection

1. At Dam Break

40

Test 6/8

Hydraulic Jump – erosion protection

1. Hydraulic Jump occurs after dambreak

41

Test 6/8

42

Test 6/8

Water Level at Point G2

Water Level at Point G2

430

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

0 10 20 30 40 50 60

Test 6/8

Test 7: River and floodplain linking

44

Test 7/8

Test 7 – HEC-RAS

45

Test 7/8

Test 7 – InfoWorks ICM

46

Test 7/8

Test 8A: Rainfall and point source surface flow in urban areas

47

Test 8B: Surface flow from a surcharging sewer in urban areas

Test 8/8

HEC-RAS beta does crash more often than you would expect…

50

Not so user friendly error messages…

1. Cells without cell center2. Cells with more than 8 faces51

Key Differences between HEC-RAS and InfoWorks ICM

2D domain dynamically linked to a 1D river and sewer network engine

Sewer Network – integrating modeling

Does everything within one package so doesn’t link with other packages

Flexible mesh – allows user friendly meshing interface

Speed of running and robustness/stability of run

Allows for Direct Rainfall modelling

QA/QC tools

Expensive

www.jacobs.com | worldwide3 September 2015 Jacobs© Copyright

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