asce 7-10 wind speed map

1

ASCE 7-10 Wind Speed MapASCE 7-10 Wind Speed Map

Peter J. VickeryApplied Research Associates, Inc.8537 Six Forks Road, Suite 600

Raleigh, NC, 27615

Expanding the Realm of Possibility

SummarySummary New Hurricane Simulation Model

Windfield Filling (weakening after landfall) Holland B (pressure-wind Relationship) Tracks and pressures (Landfall location and intensity)

Results in Lower Design Wind Speeds Moving to strength wind speed map (wind load factor = 1 for

strength design, 0.63 for ASD) Strength map corresponds to 700 year RP

ASCE 7-05 Equivalent Map = V700/√1.6

Cat III and IV structures use 1700 year RP winds Cat I structures use 300 year RP winds

2


VV700700/√1.6/√1.6

Notes:1. Values are nominal design 3-second gust wind speeds in miles per hour (m/s) at 33 ft (10m) above ground for Exposure C category.2. Linear interpolation between contours is permitted.3. Islands and coastal areas outside the last contour shall use the last wind speed contour of the coastal area.4. Mountainous terrain, gorges, ocean promontories, and special wind regions shall be examined for unusual wind conditions.

Location Vmph (m/s)

Hawaii 102 (45)

Guam 155 (69)

Virgin Islands 132 (59)

American Samoa 125 (56)

Puerto Rico

90(40)

85(38)

90(40)

120(54)110(49)

100(45)

90(40)

90(40)

100(45)

110(49)

120(54)

130(58)

130(58)120(54)

130(58)

90(40)

100(45)110(49)

130(58) 130(58)

120(54)

110(49)

110(49)

90(40)

100(45)

140(63)

110(49)

120(54)

120(54)

110(49)

140(63)

3


VV700700/√1.6/√1.6

4

ASCE 7-05 ASCE 7-10 Equivalent


700 Year Return Period Winds700 Year Return Period Winds

5


Location Vmph (m/s)

Hawaii 129 (58)

Guam 196 (88)



Puerto Rico

114(51)

108(48)

114(51)

114(51)150(67)

140(63)120(54)

130(58)

170(76)160(72)

180(80)

180(80)

170(76)

160(72)

150(67)

140(63)

140(63)

150(67)

140(63)

130(58)

120(54)

114(51)

110(49)

150(67)

120(54)130(58)140(63)

158(71)

158(71)

150(67)

140(63)

130(58)

120(54)

110(49)

150(67) 160(72)

170(76)



6



7


Location Vmph (m/s)

Hawaii 143 (64)

Guam 211 (94)



Puerto Rico

122(55)

115(52)

122(55)

122(55)

130(58)

140(63)150(67)

160(72)

170(76) 180(80)

150(67)160(72)

170(76)

180(80)

190(85)

200(89)

200(89)

160(72)

150(67)

140(63)

130(58)

122(55)

160(72)

150(67)

167(75)

167(75)

160(72)150(67)

140(63) 130(58)

120(54)

116(52)

116(52)

120(54)

130(58)

140(63)

150(67) 160(72) 170(76)

180(80)


Simulation MethodologySimulation Methodology

8


Additional Data in New ModelAdditional Data in New Model

9

Parameter 2000

Model Current Model Increase

Number of full scale wind speed traces (with maximum wind recor ded) used to validate windfield model

63 245 390%

Number of dropsonde profiles used to verify marine boundary layer model

0 650

Number of hurricanes used to develop Holland B model 17 35 100% Number of landfall hurricanes 167 189 13% Number of la ndfall intense hurricanes (defined by pressure) 70 84 20% Number of hurricanes used to develop filling model 38 57 68% Number of years of landfall data used to develop model 96 107 11%


Landfall PressuresLandfall Pressures

10

TX

890

910

930

950

970

990

1 10 100 1000Return Period (years)

LA

890

910

930

950

970

990


890

910

930

950

970

990

1 10 100 1000

SW FL

890

910

930

950

970

990


SE FL

890

910

930

950

970

990


890

910

930

950

970

990

1 10 100 1000

890

910

930

950

970

990

1 10 100 1000890

910

930

950

970

990

1 10 100 1000



11

TX

890

910

930

950

970

990


LA

890

910

930

950

970

990


M S and AL

890

910

930

950

970

990


NW FL

890

910

930

950

970

990


SW FL

890

910

930

950

970

990


SE FL

890

910

930

950

970

990


NE FL

890

910

930

950

970

990


GA and SC

890

910

930

950

970

990


NC

890

910

930

950

970

990


VA, M D and NJ

890

910

930

950

970

990


NY/NE

890

910

930

950

970

990


Gulf Coast

890

910

930

950

970

990


Florida Coast

890

910

930

950

970

990


Atlantic Coast

890

910

930

950

970

990


US Coast

890

910

930

950

970

990



Coastal SegmentsCoastal Segments

12



13

Region 5

890

910

930

950

970

990


Region 6

890

910

930

950

970

990


Region 7

890

910

930

950

970

990


Region 8

890

910

930

950

970

990


Region 9

890

910

930

950

970

990


Region 10

890

910

930

950

970

990


Region 11

890

910

930

950

970

990


Region 12

890

910

930

950

970

990


Region 13

890

910

930

950

970

990


Region 14

890

910

930

950

970

990


Region 15

890

910

930

950

970

990


Region 16

890

910

930

950

970

990


Region 17

890

910

930

950

970

990


Region 18

890

910

930

950

970

990


Region 19

890

910

930

950

970

990


Region 20

890

910

930

950

970

990


890

910

930

950

970

990

1 10 100 1000

Region 22

890

910

930

950

970

990

1 10 100 1000

Region 23

890

910

930

950

970

990

1 10 100 1000890

910

930

950

970

990

1 10 100 1000



14

890

910

930

950

970

990

1 10 100 1000

890

910

930

950

970

990

1 10 100 1000890

910

930

950

970

990

1 10 100 1000

890

910

930

950

970

990

1 10 100 1000

Regions 5 and 6

890

910

930

950

970

990


Regions 6 and 7

890

910

930

950

970

990


Regions 7 and 8

890

910

930

950

970

990


Regions 8 and 9

890

910

930

950

970

990


Regions 9 and 10

890

910

930

950

970

990


Regions 10 and 11

890

910

930

950

970

990


Regions 11 and 12

890

910

930

950

970

990


Regions 12 and 13

890

910

930

950

970

990


Regions 13 and 14

890

910

930

950

970

990


Regions 14 and 15

890

910

930

950

970

990


Regions 15 and 16

890

910

930

950

970

990


Regions 16 and 17

890

910

930

950

970

990


Regions 17 and 18

890

910

930

950

970

990

1 10 100 1000

Regions 18 and 19

890

910

930

950

970

990

1 10 100 1000

Regions 19 and 20

890

910

930

950

970

990

1 10 100 1000

Regions 20 and 21

890

910

930

950

970

990

1 10 100 1000


Landfall PressureLandfall Pressure

15

Florida Coast

890

910

930

950

970

990


890

910

930

950

970

990

1 10 100 1000


2008 Model vs. 2000 Model2008 Model vs. 2000 Model

16

100 Year Return Period

0

10

20

30

40

50

60

70

0 500 1000 1500 2000 2500 3000 3500

MilePost

Marine Gust Wind Speed

(m/sec)

Current Model

Vickery, et al (2000)

50 Year Return Period

0

10

20

30

40

50

60

70

0 500 1000 1500 2000 2500 3000 3500

MilePost

Marine Gust Wind Speed

(m/sec)

Current Model

Vickery, et al (2000)


Simulated vs. Historical Simulated vs. Historical Maximum Wind SpeedsMaximum Wind Speeds

17

0

20

40

60

80

100

1 10 100 1000

Return Period (years)

Peak Gust Wind Speed (m/sec)

ModeledSimulatedPowell & Reinhold (2007)Powell (2007)Powell & Aberson (2001)Dunion et al, (2003)HWindFIU FCHLPMHouston & Powell (2003)Goldman & Ushijima (1974)

Hazel

CarlaBetsy (LA)

CharleyLabor DayCamille Andrew

Donna

Audrey Carman

1926 - Miami



18

Texas

0

20

40

60

80

100

1 10 100 1000


Peak Gust Wind Speed

(m/sec)Carla

AudreyCelia

1932

1900

Louisiana

0

20

40

60

80

100

1 10 100 1000



(m/sec) CamilleBetsy

KatrinaAudrey

CarmenAndrew

Rita

M S/AL

0

20

40

60

80

100



(m/sec) Camille

Katrina

1926Frederic

Elena

Florida

0

20

40

60

80

100


Wind Speed (mph)

CharleyLabor Day

Andrew1926

Donna


(m/sec) Hugo

GracieHazel

Able

1911


(m/sec)

Hazel

Fran 1944

Helene

Donna

Isabel

Floyd

Diana


(m/sec)

HazelIsabel

Ione

DonnaFloydPeak Gust Wind Speed

(m/sec)

19381944

GloriaDonna

Carol


(m/sec)

1944

1938

EdnaBob

Donna


(m/sec)Edna

1938Donna1944

Gerda



19

GA/SC

0

20

40

60

80

100

1 10 100 1000


North Carolina

0

20

40

60

80

100

1 10 100 1000


VA/M D/DE/NJ

0

20

40

60

80

100

1 10 100 1000


NY/CT/RI

0

20

40

60

80

100




20

Region-FL1 (Escambia to Gulf)

0

20

40

60

80

100

1 10 100 1000Return Period (Years)


(m/sec)

Eloise

1926

Region-FL2 (Franklin to Levy)

0

20

40

60

80

100



(m/sec)

EasyKate

Region-FL3 (Citrus to Manatee)

0

20

40

60

80

100



(m/sec)

Charley

Easy

Region-FL4 (Sarasota to Collier)

0

20

40

60

80

100



(m/sec)

CharleyDonna

Region-FL5 (Monroe)

0

20

40

60

80

100



(m/sec)Andrew

1935 Labor Day

Region-FL6 (Miami-Dade to Palm Beach)

0

20

40

60

80

100



(m/sec)Andrew

1926

Region-FL7 (Martin to Brevard)

0

20

40

60

80

100



(m/sec) 19281949

Region-FL8 (Seminole to Nassau)

0

20

40

60

80

100



(m/sec)

DoraDavid


Landfall Pressures vs. RPLandfall Pressures vs. RP

21

TX

890

910

930

950

970

990


LA

890

910

930

950

970

990


MS and AL

890

910

930

950

970

990


NW FL

890

910

930

950

970

990


SW FL

890

910

930

950

970

990


SE FL

890

910

930

950

970

990


NE FL

890

910

930

950

970

990


GA and SC

890

910

930

950

970

990


NC

890

910

930

950

970

990


VA, MD and NJ

890

910

930

950

970

990


NY/NE

890

910

930

950

970

990


Gulf Coast

890

910

930

950

970

990


Florida Coast

890

910

930

950

970

990


Atlantic Coast

890

910

930

950

970

990


US Coast

890

910

930

950

970

990



Landfall Intensity (by Landfall Intensity (by Pressure)Pressure)

22

0

0.05

0.1

0.15

0.2

0.25Intense Hurricane Landfall Rate by Region

ObservedMean - Vickery, et al ( 2008a)Mean - Vickery, et al ( 2000a)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

All IH Storms Category 3 Storms

Category 4 Storms

Category 5 Storms

Annual Rate of Landfall of US Intense Hurricanes

Observed

Mean - Vickery et al. ( 2008a)Mean - Vickery et al. ( 2000b)


QUESTION:QUESTION:If the new model produces If the new model produces more intense hurricanes more intense hurricanes

(defined by pressure) than (defined by pressure) than the old model, why have the the old model, why have the

design wind speeds gone design wind speeds gone down?down?

23


ANSWER:ANSWER:Because of the New Model Because of the New Model

for the Holland for the Holland BB Parameter Parameter

24


What is B?What is B?

25



26

0

10

20

30

40

50

60

0 1 2 3 4 5 6 7 8 9 10

Distance from Storm Center (r/RMW)

Gradient Balance Wind Speed

(ms

-1)

B = 0.75B = 1B = 1.3

B = 1.5

930

940

950

960

970

980

990

1000

1010

1020

0 1 2 3 4 5 6 7 8 9 10


Pressure e (hPa)

B = 0.75B = 1

B = 1.3B = 1.5



27

0

10

20

30

40

50

60

0 1 2 3 4 5 6 7 8 9 10


Gradient Balance Wind Speed

(ms

-1)

B = 0.75B = 1B = 1.3

B = 1.5

930

940

950

960

970

980

990

1000

1010

1020

0 1 2 3 4 5 6 7 8 9 10


Pressure e (hPa)

B = 0.75B = 1

B = 1.3B = 1.5

B

c r

RMWpprp ⎥⎦

⎤⎢⎣

⎡−⋅Δ+= exp)(

24

])(exp[)(

2/1

22 frfrr

RMWpB

r

RMWV

B

BG −

⎥⎥⎥⎥

⎦

⎤

⎢⎢⎢⎢

⎣

⎡

+−Δ

=ρ

ρepB

VGΔ

≈max


Statistical Model for Holland Statistical Model for Holland B ParameterB Parameter

28


Holland B Pressure FitsHolland B Pressure Fits

29

050100150

940

960

980

1000

1020Andrew -1992/08/23-0542,B=1.6, Δp=75mb,RMW=11km

Radius(km)

Pressure(hPa)

050100150

940

960

980

1000

1020


B ParameterB Parameter

30

900

920

940

960

980

1000

1020

0 25 50 75 100 125 150

Hurricane Allen (Δ =106 , p mbRMW=15 , =1.45)km B


Statistical Model for BStatistical Model for B

31

0.00

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Holland B Parameter

SQRT(A)

B from Equation 2B from Vickery, et al. (2000)Data1992 Andrew1999 Floyd1998 Georges

⎟⎟⎠

⎞⎜⎜⎝

⎛

⋅Δ

+⋅

⋅=

ep

pTR

fRMWA

csd 1ln2


Holland B from Wind Field Holland B from Wind Field AnalysesAnalyses

32

y = -0.8408x + 1.5773R_ = 0.2658

0.0

0.5

1.0

1.5

2.0

2.5

0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80SQRT(A)

Atlantic Coast and Florida Peninsula Hurricanes

B from Equation 5B from Equation 6B Estimated from Wind ModelingLinear (B Estimated from Wind Modeling)

FredericElena

Ike

y = -0.7532x + 1.2907R_ = 0.0757

0.0

0.5

1.0

1.5

2.0

2.5

0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80

SQRT(A)

Gulf Coast Hurricanes

B from Equation 5B from Equation 6B Estimated from Wind ModelingLinear (B Estimated from Wind Modeling)


Mean B at Land Fall (old vs. Mean B at Land Fall (old vs. new modelsnew models

33

"

"

" ""

"

" " "

"

"

"

"

"

"

"

"

"

"

"

"

"

"

"

"

" 1.15,0.62

1.19,0.76

1.22,0.83

1.20,0.81

1.22,0.91

1.23,0.97

1.23,1.01

1.24,1.03

1.25,1.05

1.24,1.07

1.27,1.11

1.29,1.17

1.30,1.20

1.30,1.22

1.28,1.17

1.27,1.15

1.27,1.12

1.24,1.081.27,1.12

1.29,1.14

1.30,1.16

1.30,1.18

1.28,1.14

1.29,1.17

1.29,1.17

1.30,1.19

"

"

""

"

"

" " "

"

"

"

"

"

"

"

"

"

"

"

"

"

"

"

"

"

2.02,1.22

2.08,1.38

2.11,1.40

2.06,1.38

2.09,1.55

2.12,1.60

2.13,1.61

2.12,1.63

2.13,1.64

2.13,1.64

2.13,1.70

2.18,1.74

2.20,1.78

2.20,1.83

2.17,1.73

2.17,1.73

2.15,1.69

2.12,1.64

2.17,1.69

2.18,1.74

2.19,1.75

2.20,1.76

2.15,1.70

2.19,1.73

2.18,1.73

2.20,1.75


Effect of B on Predicted Effect of B on Predicted Wind SpeedsWind Speeds

34

0

50

100

150

200


Wilmington, NC

B from Vickery, et al. (2000)B from Vickery and Wadhera (2008)


Effect of B on Predicted Effect of B on Predicted Wind SpeedsWind Speeds

35

0

50

100

150

200


0

50

100

150

200


Miami, FL

B from Vickery, et al. (2000)

B from Vickery and Wadhera (2008)


SummarySummary

New model produces more landfall intense hurricanes by pressure than the model used to develop ASCE 7, yet results in lower wind speeds.

Additional flight level data and improved statistical model for B resulted in lower ~10% estimates of the Holland B parameter.

In some areas (e.g. Florida Panhandle) the new model produces fewer land falling strong hurricanes, and hence wind speeds are lower than associated with the reduction of B alone.

36


Windborne Debris RegionWindborne Debris Region

Current Standard V > 120 or 110 within one mile of coast

Exact Mapping (new 700 year map) 120√1.6=152~150 110 √1.6=139~140

New WBDR is intended to mimic current standard, pending new research V > 140 or 130 within one mile of coast Results in less area within WBD Region that the

existing standard

37


Wind Borne Debris RegionWind Borne Debris Region

38

asce 7-10 wind speed map

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