Hurricane Damage
Several damages and destructions are caused by
hurricane which are not that new and surprising considering how powerful
and destructive it is. Its effects can be dangerous even when it is still
to make a landfall but most of the damages it causes to us and environment
are from its landfall.
Each phenomenon below contributes and could lead to the
more devastating effects of hurricane to people, homes, nature, among
others.
Strong Winds- it adds to the severity of
hurricane's force.
Storm Surge - is an abnormal increase in the ocean's level,
sometimes in excess of several meters high and miles wide. Storm surges
can come ashore up to five hours before the storm destroy low elevation
coastal areas, and consequently, is responsible for most hurricane related
deaths. It is specially damaging when the storm surge occurs during high
tide.
Flooding
- is a common occurrence with hurricanes. Heavy rains and ocean
waters brought ashore by strong winds can result in flooding exceeding 50
cm. (20 in.) over a 24 hour period. The runoff systems in many cities
cannot handle such an increase in water because of the gentle topography
in many of the coastal areas where hurricanes occur.
Tornadoes
- may also develop in hurricanes. A number of theories exist in
its origin but in the case of Hurricane Andrew, severe damage was
inflicted by small Spin-Up Vortices that developed in the regions of
strong wind-shear found in the hurricane's eye wall. The strong damaging
winds of hurricane frequently cover the smaller tornado paths making the
separation of their damaging effects very difficult.
Rip Tides - Rip tides are strong
sea currents which push away from the shore as a strong storm is near.
They are formed by the strong winds pushing water towards the shore.
Tropical cyclones' winds push waves up against the shoreline even if they
are hundreds of miles away, so rip tide warnings are often the first
indication of a nearby hurricane.
Damage Caused by Hurricanes
High
winds are a primary cause of hurricane-inflicted loss of life and property
damage. Another cause is the flooding resulting from the coastal storm
surge of the ocean and the torrential rains, both of which accompany the
storm. The Saffir-Simpson scale is the standard scale for rating the severity of
a hurricane as measured by the damage it causes. It classifies hurricanes
on a hierarchy from category 1 (minimal), through category 2
(moderate), category 3 (extensive), and category 4 (extreme), to category
5 (catastrophic). Only two category-5 storms have hit the United
States since record-keeping began—the 1935 Labor Day hurricane, which
devastated the Florida Keys, killing 600, and Hurricane Camille in 1969,
which ravaged the Mississippi coast, killing 256 and causing damage
estimated at $1.4 billion. Hurricane Mitch in 1998 was a category-5 storm
at peak intensity over the western Caribbean, and Hurricane Gilbert in
1988 was a category-5 storm at peak intensity and is the strongest
Atlantic tropical cyclone of record. The 1970 Bay of Bengal tropical
cyclone killed about 300,000 persons, mainly by drowning. In the United
States, Hurricanes Hugo (1989) in Charleston, S.C., and Andrew (1992) in
Homestead, Fla., caused billions of dollars worth of damage. Other
hurricanes can still cause major flooding and damage, even when downgraded
to a tropical storm, as did Hurricane Agnes (1972). To decrease such
damage several unsuccessful programs have studied ways to “defuse”
hurricanes in their developing stages; more recent hurricane
damage-mitigation steps have included better warning systems involving
real-time satellite imagery. A hurricane watch is issued when there is a
threat of hurricane conditions within 24–36 hours. A hurricane warning is
issued when hurricane conditions (winds greater than 74 mph/119 kph or
dangerously high water and rough seas) are expected in 24 hours or less.
Hurricane Damage to Homes
Catastrophic failure of one- and two-story
wood-frame buildings in residential areas during Andrew was observed more
frequently than the catastrophic failures of other types of buildings.
Because less engineering oversight is applied to design and construction,
residential construction is especially vulnerable to damage during
hurricanes. As opposed to hospitals and public buildings, which are called
"fully engineered," and offices and light industrial buildings, which are
considered "marginally engineered," residential construction is
categorized as "non-engineered." Historically, the bulk of the wind damage
in the United States has occurred to residential construction. Fully
engineered construction, on the other hand, performs well in high winds,
because of the attention given to connections and load paths.
When houses are exposed to hurricane forces, roofs are most susceptible to
damage, followed by walls and openings, and then foundations. After
Hurricanes Andrew and Iniki, the Department of Housing and Urban
Development (HUD, 1993) surveyed damaged homes from both storms. HUD used
a scale that identified not only the number of homes damaged, but the
degree of damage (ranging from one-third or less, to two-thirds or more)
to each home. Figure 10 summarizes home elements suffering damage levels
of one-third or more from Hurricanes Andrew and Iniki. The chart shows
clearly that roofs are damaged more often, followed by walls and
foundations. It is worth noting that water damage was a significant factor
in both storms.
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