2011 was a record-breaking year for natural disasters in the US. It was the most expensive and deadliest hurricane season since 2008, with hurricanes Irene and Lee causing $8 billion and $1 billion in damage respectively. The 2011 tornado season saw 1,559 tornadoes, the third most active since 1980, resulting in 552 deaths, more than the previous ten years combined. Flooding from various storms caused over $10 billion in losses across the country.
Core Logic® 2011 Natural Hazard Risk Summary And Analysis
1. CoreLogic® 2011
Natural Hazard Risk
Summary and Analysis
Howard Botts, PhD
Wei Du, PhD
Brady Foust, PhD
Thomas Jeffery, PhD
2. Executive Summary
2011 Natural Hazard Risk
Summary and Analysis
As it has been noted by numerous scientists, risk analysts and other forecasters, 201 1
proved to be a record-breaking year for natural catastrophes in the United States and
around the world. Hurricanes, wildfires, tornadoes, earthquakes and various flooding
events caused billions of dollars in property damage, put disaster readiness plans and
emergency responders to the test in major U.S. urban areas, and resulted in a significant
number of lost lives across the country. Now, in addition to reviewing the immediate
structural, geographic and financial impact of the past year’s catastrophic events, it’s
crucial to consider notable changes in natural hazard incidents as part of a longer-term
perspective and evaluate the implications of these trends.
One of the most noteworthy statistics to emerge from this annual natural hazard review
is that 201 was the most expensive and the deadliest hurricane season for the U.S. since
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2008. Though only three named Atlantic storms made landfall, they caused at least a
combined $8 billion in damage, primarily from flooding. In addition, the 201 tornado
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season was the third most active since 1980. The 1,559 storms to date this year resulted
in the deaths of 552 people, which amount to the combined total number of casualties
over the previous ten years.
While the 201 wildfire season continued the trend of having fewer but larger wildfires,
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there was a significant geographic shift in home losses over the past year from California,
which had a cooler and wetter-than-average fire season, to the drought-affected states of
Texas, New Mexico and Oklahoma. In fact, total burned wildfire acreage in California was
down 90 percent in 2010-201 compared to 2007-2008. At the same time, the Wallow
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fire in Arizona burned 469,000 acres and was the largest fire in the state’s history.
Also important to note is that two non-western U.S. earthquakes occurred this year in
Virginia and Oklahoma – events that startled many residents who believed earthquakes
to be strictly a far west U.S. phenomenon. Though in reality earthquake activity in 2011
mirrored the long-running trend of quake concentration in the western U.S., where
underlying geology and plate tectonics generate a more active seismic zone, the two
unexpected events in the Midwest and Northeast caused a considerable stir among
homeowners, insurers and many others affected by the quakes.
The CoreLogic Natural Hazard Risk Summary and Analysis provides an overview of the
most significant catastrophic natural hazard events that took place in 201 as well as a
1,
brief analysis of potential risk in the coming year and the implications of unexpected
changes in natural hazard frequency, intensity and geographic patterns.
3. CoreLogic® 2011 Natural Hazard Risk Summary and Analysis
HURRICANES
Year in Review
This year was the most expensive and deadliest hurricane season since 2008. While only
SNAPSHOT three of the 18 named Atlantic Ocean storms struck the U.S. (Hurricane Irene, Tropical
While the direct impact Storm Lee and Tropical Storm Don), those storms resulted in at least $8 billion in
on New York City from damage and 45 people killed. Much of the property damage associated with the storms
Hurricane Irene (a was a result of flooding from intense rainfall as opposed to wind or storm surge flooding.
Category 1 hurricane) Overall, 201 was the seventh most active hurricane season to date in terms of property
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was ultimately minimal, and life losses since tracking began in 1851.
there are some important
lessons to be learned from Hurricane irene: The largest and most destructive storm of 201 Hurricane Irene,
1,
this event. The evacuation made landfall over coastal North Carolina on August 27. The storm tracked northward
order, affecting 370,000 along the Mid-Atlantic coast (moving over Virginia, Washington, D.C., Maryland, New
residents, suggests the
Jersey, New York, Connecticut, Rhode Island, Massachusetts and Vermont) causing
city lacks confidence
torrential rainfall and flooding across much of the northeastern U.S. Especially hard hit
in the flood control
infrastructure. In fact,
were New York, New Jersey and Vermont, which experienced extensive flood damage.
New York City does not According to the National Climatic Data Center, the total cost of the hurricane was more
have sufficient capacity than $7.3 billion, of which the associated flood damage was about $2 billion. Comparing
to defend itself from the flood damage over the past several years with the flood damage from Hurricane Irene (see
storm surge associated Figure 1), the flood loss from this single hurricane ranks as the second most expensive in
with catastrophic this region.
hurricane events, which
would be a storm
Annual Flood Damage in Northeast and Hurricane Irene
classified as Category 2 or
5
greater. With major tunnel
and subway entrances
only four feet above sea
level, even a modest 4
hurricane-driven storm
surge would result in Hurricane Irene
Flood Loss in $billions
NC, VA, MD, NJ, NY, CT, RI, MA, VT
significant inundation and
could easily lead to billions 3
in economic loss.
2
1
0
1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
Water Year
Figure 1 - Comparison of Historical Flood Losses and Irene (1999 hurricane flood losses were the result of Hurricane
Floyd, with an estimated $4.5 billion in damages and 56 people killed.)
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5. CoreLogic® 2011 Natural Hazard Risk Summary and Analysis
FLOODING
Year in Review
SNAPSHOT In 201 there were a number of climate disaster events across the U.S. that each resulted
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The U.S. Army Corps of
in flood losses exceeding $1 billion, according to data from the National Climate Data
Engineers opened the Center (NCDC):
Morganza spillway in ► Tropical Storm Lee, September 201 caused an estimated $1 billion in flood
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Louisiana on May 14, 2011
damage, with particularly severe impact on the states of Pennsylvania and New York.
to divert record-high
Mississippi River water ► Hurricane Irene, August 201 caused an estimated $2 billion in flood damage (out
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levels away from densely of $7.3 billion in total damage).
populated metro areas
like Baton Rouge and ► In the summer of 201 the melting of an above-average snowpack across the
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New Orleans. The spillway northern Rocky Mountains combined with abnormally high precipitation caused
was intended to relieve the Missouri and Souris rivers to swell beyond their banks across the upper
pressure on downstream Midwest. The resulting flooding caused an estimated $2 billion in losses.
levees, sparing hundreds
of thousands of homes ► In the spring and summer of 201 record-breaking rainfall in the Ohio Valley (nearly
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as well as numerous oil 300 percent over normal precipitation amounts) combined with melting snowpack
refineries and chemical caused historical flooding along the Mississippi River and its tributaries. Flood loss
plants along the estimates from the Mississippi River inundation are estimated to be $4 billion.
Mississippi River.
CoreLogic analysis at
the time showed that Moving Average Trend Analysis of U.S. Flood Losses
many homes in otherwise $50.00
low-risk zones were
suddenly in the path of $45.00
U.S. Flood Loss in $billions
floodwaters and that a Actual Flood Losses
$40.00
total of 21,272 homes were Moving Average Trend of Flood Losses
at risk of being fully or $35.00
partially inundated by the
$30.00
floodwaters flowing down
from the Atchafalaya $25.00
Basin. Of the more than
20,000 homes located $20.00
in the overall potential
$15.00
Atchafalaya flood area,
4,528 homes are located $10.00
outside of Federal
Emergency Management $5.00
Agency (FEMA) defined $0.00
flood zones and are, 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020
therefore, not required
to maintain flood
Water Year
insurance policies. Figure 3 – U.S. Flood Loss Trend Analysis
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7. CoreLogic® 2011 Natural Hazard Risk Summary and Analysis
TORNADOES
Year in Review
As of December 1, a total of 1,559 confirmed tornadoes have been reported in the U. S.,
SNAPSHOT making 201 the third most active tornado season since 1980 (see Figure 4 below). The
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The “2011 Super Outbreak” number of tornadoes in 201 was also significantly above the yearly average of 1,125
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occurred between April (1980 - 2010). In particular, April represented a huge anomaly with 762 confirmed
25 and April 28, and has touchdowns, 200 over the previous record.
been identified as the
largest tornado outbreak
ever recorded with 336
Tornadoes by Year
confirmed tornadoes
spread across the 2,000
South, Midwest and the 1,800
Northeast. In addition, 1,600
April 27 was the single
1,400
deadliest day since
1925, with 324 tornado- 1,200
related deaths. The most 1,000
destructive storm of the 800
outbreak, an EF5 tornado,
struck Tuscaloosa, Ala.,
600
destroyed a significant 400
part of the town and 200
resulted in 51 deaths. 0
Insured loss estimates
80
82
84
86
88
90
92
94
96
98
0
02
4
6
8
10
0
0
0
0
for the four-day outbreak
20
19
19
19
19
19
19
19
20
19
19
20
19
20
20
20
range from $3.5 to $5
billion, with the Tuscaloosa Figure 4 – Confirmed U.S. Tornadoes by Year
damage alone estimated
in excess of $2 billion.
What really set the 201 tornado season apart from previous years was the number of
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Not quite a month later, casualties, with a total of 552 as of December 1. The total number of deaths in 201 1
on May 22, another EF5 alone is equal to the previous ten years of tornado-related deaths combined. Given that
tornado struck Joplin, we live in the era of Doppler radar, which has lead to earlier and more accurate tornado
Mo., plowing a mile-wide
warnings, this number is exceptionally extraordinary. The direct urban hits by tornadoes
path directly through
in Tuscaloosa, Ala. and Joplin, Mo. greatly contributed to the exceedingly high number
the southern part of the
city, killing 161 people
of casualties.
and causing tremendous
damage to the city. The
most recent insurance
Implications and Projections
payout estimates for the In most years, with the exception of large catastrophe losses from earthquakes or
Joplin tornado are in hurricanes, wind and hail damage from cyclonic storms are major contributors to
excess of $2.2 billion. insurance claim losses. In the past, companies were confident they had an accurate
underwriting knowledge of the areas, such as “tornado alley,” that resulted in the
greatest claims. During the past few years, however, property, casualty and commercial
insurers have begun to realize they need to carefully reevaluate this perception. For
many companies, the result of actuarial analysis of claims loss against granular damaging
winds and hail geospatial databases has led to a considerable expansion of areas now
considered higher risk for wind and hail claims loss.
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9. CoreLogic® 2011 Natural Hazard Risk Summary and Analysis
Implications and Projections
California Wildfire Acres A review of past fire seasons indicates
1600 that wildfire activity often follows a
cyclical pattern of increase and decrease
1400
Thousands of Acres
due to changing seasonal weather
1200 patterns. Colder and wetter weather
1000 in areas prone to wildfires is often
the precursor to a dramatic increase
800 in the number and size of wildfires in
600 subsequent years, as a result of greater
400 than normal vegetation growth during
times of increased precipitation. It
200 would not be unreasonable to expect
0 parts of California to see a similar trend
2006 2007 2008 2009 2010 2011 in the next few years, with wildfire
acreage increasing dramatically from
the current historic lows to higher, more
Figure 7 – California Wildfire
Acres Burned 2006 - 2011
typical levels.
In addition, persistent and intensifying drought conditions are forecast for an even larger
section of the U.S. for the coming year, extending in a continuous band from Arizona
to South Carolina and as far north as Kansas and Missouri. Much of the increase in
wildfire activity for 201 in Texas, Arizona and New Mexico was the result of the persistent
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drought conditions in those areas (see Figure 8 below), which is expected to intensify and
spread in the early part of 2012.
U.S. Seasonal Drought Outlook
Drought Tendency During the Valid Period
Valid November 17, 2011 - February 29, 2012
Released November 17, 2011
Some
Improvement
Improvement
Some
Improvement
Improvement
Development Development
KEY: Persistence
Drought to persist or
No Drought
intensify
Posted/Predicted
Drought ongoing, some
Depicts large-scale trends based on subjectively derived probabilities guided
improvement by short- and long-range statistical and dynamical forecasts. Short-term events
Drought likely to improve, -- such as individual storms -- cannot be accurately forecast more than a few days in advance.
impacts ease Use caution for applications -- such as crops -- that can be affected by such events.
"Ongoing" drought areas are approximated from the Drought Monitor (D1 to D4 intensity).
Drought development For weekly drought updates, see the latest U.S. Drought Monitor. NOTE: the green improvement
likely areas imply at least a 1-category improvement in the Drought Monitor intensity levels,
but do not necessarily imply drought elimination.
Figure 8 – U.S. Seasonal Drought Outlook
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11. CoreLogic® 2011 Natural Hazard Risk Summary and Analysis
Despite the seemingly unexpected 201 earthquake events in Virginia and Oklahoma,
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seismic activity has typically been concentrated in the west over the past 15 years, as
shown in Figure 1 This is a long-running trend reflecting the underlying geology and
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plate tectonics of the western U.S.
Total U.S. Earthquakes by State (past 15 years)
20
18
# of Earthquakes 16
14
12
10
8
6
4
2
0
ID
V
R
A
T
A
T
Y
Z
O
L
R
IL
IN
E
O
M
H
K
TX
VA
IA
LA
S
E
H
Y
SD
TN
V
A
M
M
U
M
N
A
W
W
N
O
O
A
W
N
O
N
C
C
M
N
Figure 11 – Total U.S. Earthquakes by State Over the Past 15 Years
One noteworthy finding in an analysis of historical U.S. earthquake data is that even
though Virginia has only experienced two quakes and New York has faced just one in the
past 15 years, both states recorded incidents that produced fairly high readings on the
Richter scale. In terms of total quakes and magnitudes, however, the West still far exceeds
the eastern U.S. in earthquake hazard events (see Figure 12 below).
Maximum Magnitude of Earthquakes (past 15 years)
8.0
Magnitude (Richter Scale)
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
A
A
V
VA
T
O
ID
Y
Y
R
TX
R
T
IN
K
M
O
Z
IL
E
IA
S
H
V
E
SD
TN
L
H
LA
A
M
M
U
M
N
A
W
W
N
O
O
A
W
N
N
O
C
C
M
N
Figure 12 – Maximum Magnitude of Earthquakes over the Past 15 Years
Implications and Projections
The two instances of non-western U.S. earthquakes this year in Virginia and Oklahoma
surprised many residents who previously thought earthquakes to be primarily a western
U.S. phenomenon. As a result, insurance companies throughout the Northeast and parts
of the Midwest that offer earthquake policies have experienced a significant increase in
inquiries relating to earthquake insurance.
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