Dissecting and Classifying the Impacts of Historic Hurricanes on Estuarine Systems . J. Court Stevenson

1. Dissecting and Classifying the Impacts of Historic Hurricanes on Estuarine Systems. J. Court Stevenson University of Maryland Center for Environmental Science Michael S. Kearney Department of Geography University of Maryland

2. Outline • Impacts of various areas in Maryland and Virginia from waves and storm surge (déjà vu all over again) • Roles played by precipitation, wind, and waves in Chesapeake hurricanes and tropical storms • Wave setup • Influence of sea level rise • Classification of storms by track and type of damage • Frequency of different types of storms • 20th century • Late 19th century

3. The Great 1667 Hurricane “Sir having this opportunity, I cannot but acquaint you with the relation of a very strange tempest which hath been in these parts with us called a hurricane which had began August 27th and continued with such violence, that it overturned many houses, burying in the ruines much goods and many people, beating to the ground such as were any wayes employed in the fields, blowing many cattle that were near the sea or rivers, into them., whereby unknown numbers have perished, to the great afflication of all people, few having escaped who have not suffered in their persons or estates, much corn was blown away, and 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 were torn up by the roots, and in many places whole woods blown down so that they cannot go from plantation to plantation. The sea, by the violence of the wind, swelled twelve feet above its usual height drowning the whole country before it, with many of the inhabitants, their cattle and goods, the rest being forced to save themselves in the mountains nearest adjoining, while they were forced to remain many days together in great want.”[i] [i] Truit, R.V. 1967. High Winds and Waves: A Chronicle of Maryland’s Coastal Hurricanes. Natural Resources Institute, University of Maryland Press,

4. Large waves have historically been devastating Galveston Island, Texas, Sept 8 1900 during a Category 4 hurricane

5. Hurricane Floyd (1999) caused massive flooding in North Carolina

6. Impacts on Maryland and Virginia Pictures from Annapolis, Maryland Eastern Shore, Southern Virginia, and Hog Island

7. Isabel: surge height and impact Cambridge tide gauge Data: PSMSL Photo: Monica Salerno Photo: Don Merritt Photo: Don Boesch Cambridge Horn Point Annapolis

8. NOAA Tide Gauge at Gloucester Point During Isabel

9. Damage In Virginia from Isabel

10. Isabel and the South Part of Hog Island, Virginia During Before After Photos: John Porter, University of Virginia

11. Classification of Hurricane/Tropical Storms Relative Impacts on Chesapeake Bay • “Backdoor” Storms – originating in the Gulf of Mexico and Atlantic hurricanes which landfall in Georgia or South Carolina, having moved considerably inland before reaching the middle Atlantic Coast • Precipitation events with runoff, more likely to produce Bay-wide if track crosses upper Bay • Outer Banks Landfall • Lower Outer Banks – tend to track along lower Virginia Eastern Shore storm surge and waves affecting lower Bay • Upper Outer Banks – tend to track west subparallel of Chesapeake Bay, storm surge and waves affecting upper and middle Bay (exception Connie in 1955)

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

13. Potomac River During 1933 “Storm King” Hurricane

14. Flood Damage From Tropical Storm Agnes in 1972

15. The Role of Wind • Storm Tide: winds piling up water on the shore – more effective than drop in pressure. Even a pressure as low as 27.93 inches would only produce a 2.5 foot rise in water level • In 1928, hurricane blowing across Lake Okeechobee produced a surge that killed 1,835 people

16. Tropical Storms = Winds < 74 mph Class #1= Winds < 95 mph (119 km hr-1) Category 1 = Winds 74-95 mph Category 2 = Winds 96-110 mph Class #2 = Winds 96-130 mph (154-209 km hr-1) Category 3 = Winds 111- 130 mph Category 4 = Winds 131 – 155 mph Class #3 = Winds >130 mph (>209 km hr-1 ) Category 5 = Winds > 155 mph Saffir-Simpson Scale

17. 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

18. Wave setup can compound the effect of sea level rise Large waves moving directly onshore Waves from Hurricane Isabel on North Carolina’s coast

19. Mean sea level has risen 30 cm(1 foot) over the last century PSMSL data Baltimore tide gauge

20. Mid-Atlantic Year temperature rise (projected) 2030 1.0 °C – 1.5 °C 2095 2.7 °C – 5.3 °C Mid-Atlantic Year sea level rise (projected) 2030 109 mm – 310 mm 2095 409 mm – 1029 mm Temperature and sea levelwill continue to rise Projected future rise in global temperature Projected future rise in global sea level Data: IPCC and Pennsylvania State University

21. 20th Century Hurricanes/Tropical Storms In Chesapeake Bay

22. Chesapeake Bay Hurricanes/Tropical Storms 1926 - 1950

23. Chesapeake Bay Hurricanes/Tropical Storms 1951 - 1975

24. Hurricanes/Tropical Storms 1976 - 2000

25. 1851 -1876 1876 - 1900 1900 - 1925

26. Conclusions • There are as many 27 different combinations of storms that can potentially the Chesapeake Bay based on track, intensity, and precipitation • However, these large number of variations can be collapsed down to: 1) “Backdoor Storms; 2) lower Outer Banks Storms; and 3) Upper Outer Banks Storms • Backdoor Storms are largely precipitation events • Lower Outer Bank Storms produce storm surges and wave setup in the lower Chesapeake Bay • Upper Outer Banks Storms can produce substantial “wind-driven” tides (wave setup) that can affect the whole Chesapeake Bay • Only 3 storms like this occurred in the 20th Century in the Chesapeake Bay

27. FINI Questions?

28. Chesapeake Bay islandsare rapidly disappearing

29. Isabel makes landfall Sept 18, 2003 Photo: NASA/MODIS

30. Risk of flooding much greater when storm surge and wave setup are considered Submergence risk determined by EPA

31. 1933 hurricane Hurricane Isabel Min pressure (" Hg) 28.7 29.1 Max sustained wind speed 70 mph 73 mph Tidal surge in Potomac River (feet above MLLW) 11.1 ' 11.3 ' Isabel same size and path as 1933 hurricane Chesapeake Biological Laboratory after the 1933 hurricane. Photo courtesy Calvert Marine Museum

32. Historical Category 2 Hurricanes In Chesapeake Bay

33. Historical Category 3 Hurricanes In Chesapeake Bay

34. Historical Category 1 Hurricanes In Chesapeake Bay

35. Impact of Sea Level Rise on Storm Waves • Wave Decay Occurs farther in shore • Zone of “saturation” of wave energy closer to bank • Overall penetration of storms significantly landwards Δ

36. Wave Energy**(Airy Wave Theory) E = 1/8ρgH2 Small Changes in Wave Height = Large Changes in Wave Energy

37. Relative wave power increased with increasing water depth 4 s wave 16’ 15’ 2 s wave 15’ 16’

38. Total flood height = sea level + storm surge + wave setup

39. Track of the storm affects direction of wave generation