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Water Level Monitoring and Flood Hazard Emergency
Management in Chesapeake BayJohn D. Boon John M. Brubaker
Virginia Institute of Marine Science
C.R. BerquistDepartment of Geology, College of William and Mary
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Should we care about climate
change?
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Jamestown Water Levels and Flood Hazard Emergency Management Project
Project Goals:• To provide emergency managers with water
level data in near real-time during tropical storm and hurricane events via the Internet
• Establish a data base of measured water level extremes as an aid to community planning
• Provide water level histories needed to verify numerical models
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7 OCT 2006 ‘NORTHEASTER’ www.worldtidesandcurrents.com
Photo courtesy of Dr. David Forrest, VIMS
www.vims.edu/physical/
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Jamestown Water Levels and Flood Hazard Emergency Management Project
Project Goals:• To provide emergency managers with water level data
in near real-time during tropical storm and hurricane events via the Internet
• Establish a data base of measured water level extremes as an aid to community planning
• Provide water level histories needed to verify numerical models
-
Jamestown Water Levels and Flood Hazard Emergency Management Project
Project Goals:• To provide emergency managers with water level data
in near real-time during tropical storm and hurricane events via the Internet
• Establish a data base of measured water level extremes as an aid to community planning
• Provide water level histories needed to verify numerical models
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In the coastal zone, extreme flooding is caused by
STORM TIDES
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Storm Tide:Sum of a Storm Surge and the
Astronomical Tide
Storm Surge: Water level change due to storm effects (wind, low pressure)
Astronomical Tide: Water rise and fall due to gravity of earth, moon and sun
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ERNESTO Storm Surge: 3.56 feet
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Storm Tide: 5.51 feet
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What a Difference a “Phase” Makes …
September, 2006
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8/318/318/318/31 9/19/19/19/1 9/29/29/29/2 9/39/39/39/30000
1111
2222
3333
4444
5555
6666Hampton Roads (Sewells Pt), VA
storm tideastronomical tidestorm surgemmsl (lunar)
2006
‘ERNESTO’
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8/318/318/318/31 9/19/19/19/1 9/29/29/29/2 9/39/39/39/30000
1111
2222
3333
4444
5555
6666
Windmill Point, VA
storm tideastronomical tidestorm surgemmsl (lunar)
Water Level (feet above MLLW)
2006
‘ERNESTO’
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50 Years of Storm Tides at Sewells Point
1957 – 2006Four Northeasters and a Hurricane
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Water levels from U.S. National Oceanic and Atmospheric Administration
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Sea Level Change at Hampton Roads, Virginia
1930 - 2005
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-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
1930
1934
1939
1943
1948
1952
1956
1961
1965
1970
1974
1979
1983
1987
1992
1996
2001
Fee
t ab
ove
198
3-20
01 M
LL
W Monthly Mean Sea Level, Hampton Roads (Sewells PT), VA
Sea Level Trend: 1.4 ft/century
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-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
1930
1934
1939
1943
1948
1952
1956
1961
1965
1970
1974
1979
1983
1987
1992
1996
2001
Fee
t ab
ove
198
3-20
01 M
LL
W Monthly Mean Sea Level, Hampton Roads (Sewells PT), VA
Sea Level Trend: 1.4 ft/century
Aug33
Sep03
Sep44Oct54Aug55
Sep60Mar62
Sep99
Water levels from U.S. National Oceanic and Atmospheric Administration
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Lower Chesapeake Bay Storm Tide Comparisons‘ERNESTO’ - September, 2006
Northeaster – October, 2006Northeaster – November, 2006
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Extratidal High Water (XHW)
A new metric for comparing storm tides
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HAT
LAT
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HAT
LAT
? ? ?
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HAT
LAT
0.83
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1.98 feet
HAT
EXTRATIDAL HIGH WATER
LAT
0.83
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JAMES RIVER (SEWELLS POINT)
0
1
2
3
4
5
6
Sep-06 Oct-06 Nov-06
EX
TRA
TID
AL
HIG
H W
ATE
R Feet
‘ERNESTO’
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RAPPAHANNOCK RIVER (WINDMILL POINT)
0
1
2
3
4
5
6
Sep-06 Oct-06 Nov-06
EX
TRA
TID
AL
HIG
H W
ATE
RFeet
‘ERNESTO’
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YORK RIVER (USCG TRAINING CENTER)
0
1
2
3
4
5
6
Sep-06 Oct-06 Nov-06
EX
TRA
TID
AL
HIG
H W
ATE
R
Feet
‘ERNESTO’
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November 2006
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YORK RIVER (USCG TRAINING CENTER)
0
1
2
3
4
5
6
Sep-06 Oct-06 Nov-06
EX
TRA
TID
AL
HIG
H W
ATE
R
Feet
‘ERNESTO’
2.5
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HURRICANES
0
1
2
3
4
5
6
AUG, 1933 ISABEL KATRINA
EX
TRA
TID
AL
HIG
H W
ATE
R
Feet
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Work in Progress at Jamestown …
Jamestown water level station
