Dissecting and Classifying the Dissecting and Classifying the Impacts of Historic Hurricanes on Impacts of Historic Hurricanes on

Estuarine SystemsEstuarine Systems..

J. Court StevensonJ. Court StevensonUniversity of Maryland Center for University of Maryland Center for

Environmental ScienceEnvironmental Science

Michael S. KearneyMichael S. KearneyDepartment of GeographyDepartment of Geography

University of MarylandUniversity of Maryland

Outline• Impacts of various areas in Maryland and Impacts of various areas in Maryland and

Virginia from waves and storm surge (déjà vu all Virginia from waves and storm surge (déjà vu all over again)over again)

• Roles played by precipitation, wind, and waves Roles played by precipitation, wind, and waves in Chesapeake hurricanes and tropical stormsin Chesapeake hurricanes and tropical storms– Wave setupWave setup

• Influence of sea level riseInfluence of sea level rise• Classification of storms by track and type of Classification of storms by track and type of

damagedamage• Frequency of different types of stormsFrequency of different types of storms

– 2020thth century century– Late 19Late 19thth century century

““Sir having this opportunity, I cannot but acquaint you with the Sir having this opportunity, I cannot but acquaint you with the

relation of a very strange tempest which hath been in these parts with relation of a very strange tempest which hath been in these parts with us called a hurricane which had began August 27us called a hurricane which had began August 27thth and continued with and continued with such violence, such violence, that it overturned many houses, burying in the ruines that it overturned many houses, burying in the ruines much goods and many peoplemuch goods and many people, beating to the ground such as were any , beating to the ground such as were any wayes employed in the fields, blowing many cattle that were near the wayes employed in the fields, blowing many cattle that were near the sea or rivers, into them., whereby unknown numbers have perished, to sea or rivers, into them., whereby unknown numbers have perished, to the great afflication of all people, few having escaped who have not the great afflication of all people, few having escaped who have not suffered in their persons or estates, much corn was blown away, and suffered in their persons or estates, much corn was blown away, and great quantities of tobacco have been lost, to the great damage of great quantities of tobacco have been lost, to the great damage of many, and utter undoing of others. Neither did it end here, but the trees many, and utter undoing of others. Neither did it end here, but the trees were torn up by the roots, and in many places whole woods blown down were torn up by the roots, and in many places whole woods blown down so that they cannot go from plantation to plantation. so that they cannot go from plantation to plantation. The sea, by the The sea, by the violence of the wind, swelled twelve feet above its usual height violence of the wind, swelled twelve feet above its usual height drowning the whole country before it, with many of the inhabitants, drowning the whole country before it, with many of the inhabitants, their cattle and goods, the rest being forced to save themselves in the their cattle and goods, the rest being forced to save themselves in the mountains nearest adjoining, while they were forced to remain many mountains nearest adjoining, while they were forced to remain many days together in great want.”days together in great want.”[i]

[i] Truit, R.V. 1967. High Winds and Waves: A Chronicle of Maryland’s Coastal Truit, R.V. 1967. High Winds and Waves: A Chronicle of Maryland’s Coastal Hurricanes. Natural Resources Institute, University of Maryland Press, Hurricanes. Natural Resources Institute, University of Maryland Press,

The Great 1667 HurricaneThe Great 1667 Hurricane

Large waves have historically Large waves have historically been devastatingbeen devastating

Galveston Island, Texas, Sept 8 1900 during a Category 4 hurricaneGalveston Island, Texas, Sept 8 1900 during a Category 4 hurricane

Hurricane Floyd (1999) caused Hurricane Floyd (1999) caused massive flooding in North massive flooding in North

CarolinaCarolina

Impacts on Maryland and Impacts on Maryland and VirginiaVirginia

Pictures from Annapolis, Maryland Eastern Shore,

Southern Virginia, and Hog Island

Isabel: surge height and Isabel: surge height and impactimpact

AnnapolisAnnapolisHorn PointHorn PointCambridgeCambridge

Photo: Monica Salerno Photo: Don Merritt Photo: Don Boesch

Cambridge tide gauge Data: PSMSL

NOAA Tide Gauge at Gloucester Point During

Isabel

Damage In Damage In Virginia from Virginia from IsabelIsabel

BeforeBefore

AfterAfter

DuringDuring

Isabel and the South Part of Hog Island, VirginiaIsabel and the South Part of Hog Island, Virginia

Photos: John Porter, Photos: John Porter,

University of VirginiaUniversity of Virginia

Classification of Hurricane/Tropical Storms Relative Impacts on

Chesapeake Bay• ““Backdoor” Storms – originating in the Gulf of Backdoor” Storms – originating in the Gulf of

Mexico and Atlantic hurricanes which landfall in Mexico and Atlantic hurricanes which landfall in Georgia or South Carolina, having moved Georgia or South Carolina, having moved considerably inland before reaching the middle considerably inland before reaching the middle Atlantic CoastAtlantic Coast– Precipitation events with runoff, more likely to produce Precipitation events with runoff, more likely to produce

Bay-wide if track crosses upper BayBay-wide if track crosses upper Bay

• Outer Banks LandfallOuter Banks Landfall– Lower Outer BanksLower Outer Banks – tend to track along lower Virginia – tend to track along lower Virginia

Eastern Shore storm surge and waves affecting lower Eastern Shore storm surge and waves affecting lower BayBay

– Upper Outer Banks – tend to track west subparallel of Upper Outer Banks – tend to track west subparallel of Chesapeake Bay, storm surge and waves affecting Chesapeake Bay, storm surge and waves affecting upper and middle Bay (exception Connie in 1955)upper and middle Bay (exception Connie in 1955)

The Role of Precipitation

• Many long-term residents vividly remember Tropical Storm record holder for the most inches of rainfall per hour in the upper Bay

• Ten Heaviest Rains in Virginia from  Ten Heaviest Rains in Virginia from       Tropical Cyclones and their Remnants Tropical Cyclones and their Remnants

• Amount        Dates                      Location Amount        Dates                      Location 27.00"           8/19-20/1969        Nelson County 27.00"           8/19-20/1969        Nelson County 19.77"           11/02-07/1985      2 NE Montebello 19.77"           11/02-07/1985      2 NE Montebello 18.13"           9/14-16/1999        Yorktown 18.13"           9/14-16/1999        Yorktown 16.57"           9/14-16/1999        Newport News 16.57"           9/14-16/1999        Newport News 16.00"           6/17-24/1972        Chantilly 16.00"           6/17-24/1972        Chantilly 14.30"           9/14-16/1999        James City 14.30"           9/14-16/1999        James City 14.30"           9/05-09/1996        Tom's Branch  14.30"           9/05-09/1996        Tom's Branch  14.18"           6/17-24/1972        Centreville 14.18"           6/17-24/1972        Centreville 14.17"           9/05-09/1996        Luray 5 SE 14.17"           9/05-09/1996        Luray 5 SE 13.60"           6/17-24/1972        Big Meadows13.60"           6/17-24/1972        Big Meadows

• The data above suggest that three classes can be used for our hurricane The data above suggest that three classes can be used for our hurricane classification system: P Class #1 = 0-10”, P Class#2 = 10-20” and P Class#3 > classification system: P Class #1 = 0-10”, P Class#2 = 10-20” and P Class#3 > 20”20”

Potomac River During 1933 “Storm King”

Hurricane

Flood Damage From Tropical Storm Agnes in

1972

The Role of Wind

•Storm Tide: winds piling up Storm Tide: winds piling up water on the shore – more water on the shore – more effective than drop in effective than drop in pressure. Even a pressure as pressure. Even a pressure as low as 27.93 inches would only low as 27.93 inches would only produce a 2.5 foot rise in produce a 2.5 foot rise in water levelwater level

•In 1928, hurricane blowing In 1928, hurricane blowing across Lake Okeechobee across Lake Okeechobee produced a surge that killed produced a surge that killed 1,835 people1,835 people

Saffir-Simpson Scale 

Tropical Storms = Tropical Storms = Winds < 74 mphWinds < 74 mph

Class #1= Winds < 95 Class #1= Winds < 95 mph (119 km hrmph (119 km hr-1-1))

Category 1 = Category 1 = Winds 74-95 mphWinds 74-95 mph

Category 2 = Category 2 = Winds 96-110 mphWinds 96-110 mph

Class #2 = Winds 96-130 Class #2 = Winds 96-130 mph (154-209 km hrmph (154-209 km hr-1-1))

Category 3 = Category 3 = Winds 111- 130 Winds 111- 130 mphmphCategory 4 = Category 4 = Winds 131 – 155 Winds 131 – 155 mphmph

Class #3 = Winds >130 Class #3 = Winds >130 mph (>209 km hrmph (>209 km hr-1 -1 ))

Category 5 = Winds Category 5 = Winds > 155 mph > 155 mph

The Role of Waves

• Waves ride on top of the storm surge– Galveston Hurricane is a classic example– Increased flooding

• As sea level rises, greater depths of water increase the potential for generation of larger waves from the same wind field– Increases the flood risk

Wave setup can compound the Wave setup can compound the effect of sea level rise effect of sea level rise

Large waves moving directly onshore

Waves from Hurricane Isabel on North Carolina’s coastWaves from Hurricane Isabel on North Carolina’s coast

Mean sea level has risen 30 cmMean sea level has risen 30 cm(1 foot) over the last century(1 foot) over the last century

Baltimore tide gauge Baltimore tide gauge

PSMSL data

Temperature and sea levelTemperature and sea levelwill continue to risewill continue to riseMid-AtlanticMid-Atlantic

YearYear temperature risetemperature rise(projected)(projected)

20302030 1.0 °C – 1.5 °C1.0 °C – 1.5 °C20952095 2.7 °C – 5.3 °C2.7 °C – 5.3 °C

Projected future rise in global temperatureProjected future rise in global temperature

Mid-AtlanticMid-AtlanticYearYear sea level risesea level rise

(projected)(projected)

20302030 109 mm – 310 mm109 mm – 310 mm20952095 409 mm – 1029 mm409 mm – 1029 mm

Projected future rise in global sea levelProjected future rise in global sea level

Data: IPCC and Pennsylvania State UniversityData: IPCC and Pennsylvania State University

2020thth Century Century Hurricanes/Tropical StormsHurricanes/Tropical Storms

In Chesapeake BayIn Chesapeake Bay

Chesapeake Bay Chesapeake Bay Hurricanes/Tropical Hurricanes/Tropical Storms 1926 - 1950Storms 1926 - 1950

Chesapeake Bay Chesapeake Bay Hurricanes/Tropical Storms 1951 Hurricanes/Tropical Storms 1951

- 1975- 1975

Hurricanes/Tropical Hurricanes/Tropical Storms 1976 - 2000Storms 1976 - 2000

1851 -18761851 -1876

1876 - 19001876 - 1900

1900 - 19251900 - 1925

ConclusionsConclusions

• There are as many 27 different combinations of There are as many 27 different combinations of storms that can potentially the Chesapeake Bay storms that can potentially the Chesapeake Bay based on track, intensity, and precipitationbased on track, intensity, and precipitation– However, these large number of variations can be However, these large number of variations can be

collapsed down to: 1) “Backdoor Storms; 2) lower Outer collapsed down to: 1) “Backdoor Storms; 2) lower Outer Banks Storms; and 3) Upper Outer Banks StormsBanks Storms; and 3) Upper Outer Banks Storms

– BBackdoor Storms are largely precipitation eventsackdoor Storms are largely precipitation events– Lower Outer Bank Storms produce storm surges and Lower Outer Bank Storms produce storm surges and

wave setup in the lower Chesapeake Baywave setup in the lower Chesapeake Bay– Upper Outer Banks Storms can produce substantial Upper Outer Banks Storms can produce substantial

“wind-driven” tides (wave setup) that can affect the “wind-driven” tides (wave setup) that can affect the whole Chesapeake Baywhole Chesapeake Bay

• Only 3 storms like this occurred in the 20Only 3 storms like this occurred in the 20thth Century in the Century in the Chesapeake BayChesapeake Bay

FINI

Questions?

Chesapeake Bay islandsChesapeake Bay islandsare rapidly disappearingare rapidly disappearing

Isabel makes landfall Sept 18, Isabel makes landfall Sept 18, 20032003Photo: NASA/MODIS

Risk of flooding much greater when Risk of flooding much greater when storm surge and wave setup are storm surge and wave setup are

consideredconsidered

Submergence risk Submergence risk determined by EPAdetermined by EPA

Isabel same size and path as 1933 Isabel same size and path as 1933 hurricanehurricane

Min pressure (" Hg)Min pressure (" Hg)

Max sustained wind speedMax sustained wind speed

Tidal surge in Potomac RiverTidal surge in Potomac River (feet above MLLW) (feet above MLLW)

28.728.7

70 mph70 mph

11.1 '11.1 '

29.129.1

73 mph73 mph

11.3 '11.3 '

19331933hurricanehurricane

HurricaneHurricane IsabelIsabel

Chesapeake Biological Laboratory after the 1933Chesapeake Biological Laboratory after the 1933hurricane. Photo courtesy Calvert Marine Museumhurricane. Photo courtesy Calvert Marine Museum

Historical Category 2 Historical Category 2 Hurricanes In Chesapeake Hurricanes In Chesapeake

BayBay

Historical Category 3 Hurricanes Historical Category 3 Hurricanes In Chesapeake BayIn Chesapeake Bay

Historical Category 1 Historical Category 1 Hurricanes In Chesapeake BayHurricanes In Chesapeake Bay

ΔΔ

•Wave Decay Occurs Wave Decay Occurs farther in shorefarther in shore

•Zone of “saturation” of Zone of “saturation” of wave energy closer to wave energy closer to bankbank

•Overall penetration of Overall penetration of storms significantly storms significantly landwardslandwards

Impact of Sea Level Rise on Storm Impact of Sea Level Rise on Storm WavesWaves

Wave EnergyWave Energy**(Airy Wave Theory)

E = 1/8ρgHE = 1/8ρgH22

Small Changes in Wave Small Changes in Wave Height = Large Changes in Height = Large Changes in

Wave EnergyWave Energy

Relative wave power Relative wave power increased with increasing increased with increasing

water depthwater depth

0

500

1000

1500

2000

1 2 3 4

Cases

Re

lativ

e W

ave

Po

we

r

15’

15’

16’

16’

2 s wave

4 s wave

Total flood height =Total flood height = sea level + storm surge + wave sea level + storm surge + wave

setupsetup

Track of the Track of the storm affects storm affects direction of direction of wave wave generationgeneration