Audio Recorded Live at the AGI Showcase Event in York. For details of more AGI Events, visit our website: www.agi.org.uk

1. Automating Flood Damage
Assessment
Katie Graves
November 2013

2. Agenda
• Introduction to Flood Damage Assessment
• Types of Flooding
• Types of Data
• Challenges
• Types of Analysis
• Increasing Efficiencies
2

3. Flood Damage Assessment
Do Nothing
Net Present Value Damages
Flood Cell 1 Flood Cell 2 Flood Cell 3 Flood Cell 4 Flood Cell 5 Flood Cell 6 Flood Cell 7 Flood Cell 8
Residential
Total
Non-residential
2,250
6,540
1,505
11,700
12,045,054
2,610
30 Year
354,045
12,956,313
807
307
257
9
1
1100
600
550
44
4
1212
712
662
50
6
30 Year CC
1162
662
612
45
5
1555
1055
1005
70
1650
1150
1100
2007
1356
856
779
75 Year
12,406,364
354,045
75 Year
30 Year
1,250
Sub-total
1,105
Ground
Floor
100 Year CC
Non-residential
5,160
Upper
Floor
75 Year CC
1,000
Ground
Floor
100 Year
Residential
Upper
Floor
Other Critical
Infrastructure
Emergency
(other than
Services
emergency
services)
Road and Rail (km)
6,427
1,392
540,541
Sub-total
2,024
11,474
2,384
-
-
353,932
Total
9,181,187
-
353,932
249,891
TOTAL
Non-residential
Sub-total
4,750
695
-
297
2,540,564 -
840
-
297
6,130
1,095
-
297
540,244 -
1,430
-
594
10,880
1,790
-
594
3,080,808 -
297
353,635
297 594
2,899,343
297
TOTAL
1,425,640
4,654,687
5,646,543
6,546,544
43,503,544
694,654
42,808,890
Do Minimum
1,350,456
1,486,223
2,478,079
3,378,080
15,606,455
654,354
52,405
77,839
103,273
128,707
4,564,064
Do Nothing
1,354
6,506
8,048
2070
onwards
12,455
140.47
0.56
279
229
9
0
50
28.83
0.20
1067
567
517
43
3
79
60.04
0.31
1173
673
623
49
4
91
74.11
0.36
1122
622
572
44
4
86
71.87
0.35
1477
977
927
67
8
146
131.17
0.52
1574
1074
1024
74
10
158
150.35
0.62
1277
777
727
57
7
114
97.51
0.54
659
159
109
4
0
40
14.37
0.20
832
332
282
22
3
58
28.01
0.31
914
414
364
22
4
69
36.77
0.36
644
144
94
2
0
37
12.84
0.20
816
316
266
17
2
55
24.18
0.31
854
354
304
18
3
62
32.11
0.36
614
114
64
0
0
33
8.71
0.15
805
305
255
17
2
53
21.67
0.31
848
348
298
18
3
61
29.37
0.36
842
342
292
21
3
62
30.23
0.36
75 Year CC
1010
510
460
26
4
85
54.50
0.50
100 Year CC
1052
552
502
29
4
91
63.30
0.58
30 Year
528
28
20
0
1
6
9.31
0.00
75 Year
249,778
533
33
25
1
1
12
21.49
0.01
100 Year
539
39
28
1
2
15
25.53
0.01
30 Year CC
540
40
30
1
1
16
23.91
0.01
Receptors benefiting from solution
14,952,101
75 Year SOP
2015
146
7,207,480
PVD
(capped)
Do Nothing
2020-2039 2040 - 2069
8
100 Year
Scenario 5
Scenario 6
Annual Averages
Risk to Life
60
64,774
Emergency Services
PVD
PVD
(pre- (disallow
capping)
ed)
0.68
806
30 Year
547,121
3,446,464
Scenario 4
Intangible benefit
2070
onwards
194.84
75 Year
Total
353,338
Risks to life
Property damages
2020-2039 2040 - 2069
2015
190
30 Year
19,416,780
Flood Cell 1 Flood Cell 2 Flood Cell 3 Flood Cell 4 Flood Cell 5 Flood Cell 6 Flood Cell 7 Flood Cell 8
297
10
75 Year
Scenario 3
Net Present Value Damages
-
0.54
77
2007
9,551,001
64,887
Emergency Services
590
170.68
30 Year CC
Baseline
9,001,504
Intangible benefit
Residential
174
75 Year CC
Scenario 1
549,497
Risks to life
75 Year SOP
0.36
9
30 Year CC
8,640,646
1,137
95.79
75 Year
Flood Cell 1 Flood Cell 2 Flood Cell 3 Flood Cell 4 Flood Cell 5 Flood Cell 6 Flood Cell 7 Flood Cell 8
Non-residential
0.37
102
100 Year
26,227,630
Net Present Value Damages
992
0.32
99.64
Receptors at risk of flooding
250,004
TOTAL
5,047
0.20
81.54
100 Year
65,000
Emergency Services
887
38.14
91
100 Year
-
Intangible benefit
Residential
56
106
549,949
12,585,708
Risks to life
Do Minimum
Rail
100 Year CC
540,654
-
Road
30 Year
-
4,564,064
Benefit
PVD
Scenario 3 over
Scenario 1
75 Year CC
578
78
28
3
1
28
39.51
0.02
254,064
100 Year CC
576
76
26
3
0
32
44.49
0.06
579
79
29
3
1
32
42.96
0.02
Do Minimum
1,154
4,504
7,540
10,654
168,713
2007
75 Year SOP
840
3,545
6,505
84,056
115,406
30 Year
648
148
98
5
1
16
23.78
0.00
75 Year
768
268
218
22
1
33
53.52
0.01
100 Year
798
298
248
28
2
37
62.88
0.01
30 Year
663
163
113
7
1
19
25.31
0.00
75 Year
784
284
234
27
2
36
57.36
0.01
100 Year
858
358
308
32
3
44
67.53
0.01
Intangible Benefit
2020-2039 2040 - 2069
2015
Benefit
2070
onwards
PVD
Do Minimum
34,540
31,640
25,456
22,840
7,654,654
75 Year SOP
3
Scenario 4 over
Scenario 1
46,546
46,546
45,466
43,515
1,387,354
Benefit
Scenario 5 over
Scenario 1

4. What is Flood Risk?
• Flood risk = probability of flooding x impact of
flooding
• Probability is the likelihood that a flood will occur over the
period of a year.
• 1% probability of flood event refers to a 1 in 100 chance of
occurrence.
• This would be a relatively large event.
• This is a flood with a 100 year return period
4

5. Flood Risk
•
•
Flooding from the sea
•
Flooding from surface water
•
Flooding from sewers
•
Flooding from groundwater
•
5
Flooding from rivers
Flooding from infrastructure failure

6. Modelling Flood Risk
• Hydraulic modelling outputs – Fluvial
(ISIS/TuFLOW)
- 1D cross section data
- 2D raster data with water levels or
water depths
• Hydraulic modelling outputs – Drainage
modelling (Infoworks ICM)
- 1D Node data
- Vector triangulated surface
representing flooding
• Topographic data
6

7. Challenges
• Rapidly modelling numerous scenarios and return periods
• Naming multiple datasets
• Long field names required
• Iterative process
• Engineers like spread sheets
• Results required rapidly as the project evolves to feed back into
the design
7

8. Flood Damage Assessment Analysis
8

9. Flood Damage Assessment Analysis
9

10. Increasing Efficiencies
• Iterative folders to run through files quickly
• File naming using in-line variable substitution (parse path)
• Results available spatially to allow any inconsistencies to be
picked up
10

11. Increasing Efficiencies
Models can be re-run with different inputs
Geodatabases essential for long file names
Models can be run be people with little GIS experience
11

12. Summary
• Flood damage assessment involves lots of complex calculations
• Using models can allow these calculations to be calculated
quickly and efficiently in a spatial environment
Next Steps:
• Encouraging engineers to adopt these approaches across multiple
projects.
• Further automate different stages of the process and ensure that
the tools are user friendly.
12

13. Any Questions?