Floods

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Floods
By Stephanie Millett Brittany Uhlman
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INTRODUCTION

• A flood is usually caused by rain, heavy
  thunderstorms, and thawing of snow.
• Its considered to be a temporary condition of two
  or more acres of dry land either
• Overflowed with inland or tidal waters
• Rapid or runoff of surface waters
• Mudflows

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How does Flooding Start and end?

• The shore or land by or surrounding a body of
  water erodes and this erosion causes waves
  currents that result in a flood.
• Flood disasters have been increased because of
  the expansion of settlements and growth in
  floodplains.
• Floods could be slow or fast but usually occur
  over a matter of days.
• After the water eventually goes down or dries up.
  On coastal floods, low tides and high tides makes
  a change in heights.

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Why does it occur??

• A flood is too much water in the wrong place.
• Sometimes a flood occurs from
• Sewer (drain) backup
• Collapse of land along the shore of a lake or
  another body of water. This results in waves or
  currents during a flood

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Where does flooding occur?

• Flooding is the most worldwide natural disaster.
  It occurs in every country and wherever there is
  rainfall or coastal hazards.
• They are most likely to happen in tropical areas
  and tsunamis.
• Most common floods happen around the worlds
  largest/greatest rivers.
• Believe it or not, smaller rivers could cause
  more damage even though people dont pay as much
  attention to them.
• Most Flooding occurs during the beginning of
  spring.

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Characteristics of a Flood

• A number of criteria determine the dangers of a
  flood. The University of Wisconsin have came up
  with the following criteria such as depth of
  water, duration, velocity, rate of rise,
  frequency or occurrence, and seasonal.
• Velocity- high velocities of flow create erosive
  forces and can do things like destroy
  foundations.
• Depth of Water- floatation, failures on
  foundation, vegetation survival, etc..
• Rate of Rise- is the rate at which the water
  level increases.
• Seasonal- the land during growing season, the
  effects on agriculture production and other
  things like that.

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How Does it Effect People?

• The amount of people effected by floods from
  1999- 2000 is reported to be approximately 1.5
  billion.
• In the U.S. alone there are 10 million people
  living in areas that could flood.

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Precautions to Take

• To remain safe from floods you need to know when
  and how to deal with them.
• Lives could be saved by having more warnings of
  floods for places in threat.
• There are things used for antiflood protection
  and it makes your house, yard and much more, safe
  and protected when a flood arrives. They can be
  used over and over again.

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Flood Protection Equipment

• This is a Door Flood Barrier. Its used to fit and
  seal your door.

This is a free standing door barrier. The
difference with this one is you can still have
use of the door as well.
Modular Flood Barrier is the highest level of
protection . Its installed to protect your whole
property from high bodies of water during a flood.
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How Forcasters Predict Floods
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Predictions of a Flood

• Deep Snow can melt into a lot of water. It
  usually floods because of rain or rapid warm
  temperatures.
• Frozen ground wont absorb as much water, the
  rain and/ or snow causes flooding on frozen
  ground.
• Full reservoirs- Reservoirs are very big and are
  man-made to hold water for drinking or
  irrigation. It wont absorb anymore water f full
  and it causes it to overflow.
• High River or Stream Levels- melting flows into a
  full river and overflows on banks.

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Government and Emergency Team Aid

• There is an organization called World
  Meteorological Organization. It promotes flood
  management and water resources management. They
  have successfully guided and promoted
  international development of meteorology and
  hydrology. They give forecasts and warnings.
• The governments responsibility of fixing things
  during a flood are for example damaged roads,
  buildings, telephones, and electricity.

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This is the natural disasters in U.S. and the
cost in millions.
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Effects on the Environment

• Sometimes its a good thing when a flood occurs.
  The environmental benefits of flooding are
  fisheries, wetlands, and irrigation.
• Flood plains have one of the highest development
  potential when it comes to economic development.
• It also makes a mess of the environment. The soil
  becomes poor because the oxygen is limited due to
  so much water. The pH in soil decreases, rate
  decomposition of organic matter in flooded soil
  tends only to be half that unflooded soil
• Trees are effected as well. It effects the
  height, age, vigor, roots, and species.
• During the growing season flooding is very
  harmful especially to woody plants compared a
  flood in a dormant season.
• Floods could carry chemicals from agricultural
  fields, sewage,etc. and cant handle large bodies
  of water.
• Crops die because they cant survive because of
  the conditions.

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Flash Floods

• Flash floods happen in a short time, they have a
  great volume of water, and are local floods.
• The runoff of intense rain results in high flood
  waves.
• Flash floods result in failure of dams and more.
• It usually happens in desert areas and mountain
  regions.
• They are a threat in steep land, high runoff
  rates, thunderstorms, and narrow streams.

This is a picture of a town after a Flash Flood
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River Floods

• Riverine floods are caused by melting of snow and
  precipitation over large areas. They take place
  in rivers. Floods in large rivers take hours to
  days.
• The ground conditions effects the runoff.

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Coastal Floods

• Coastal floods are caused by tides, storms,
  tropical cyclones, or tsunamis.
• They happen in the ocean and effects the general
  public and maritime interests along the
  coastline.
• They are caused by heavy surf, tidal piling, and
  storm surges,
• Other factors are tidal cycles, behaviors of the
  storm, river or stream runoff, no offshore reefs
  or other barriers, and high winds.

Venezuela in December of 1999.
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Urban Floods and Ice Jams

• Urban floods are when the land is turned from
  fields or woods into roads and parking lots.
  Since this happens it cant absorb the rainfall.
• During the urban floods all the streets become
  rivers and basements become full of water, they
  are death traps.
• Ice Jam is floating ice that adds up at a
  man-made or natural area and stops the flow of
  water. This causes the area to flood.

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Lakeshore Floods

• Lakeshore floods affect the general public as
  well as some areas of the Great Lakes.
• These floods extend from the beaches to rivers
  that flow into lakes. The extent of the flooding
  is dependant on surrounding the shore terrain.
  The causes of these lakeshore floods are seiches
  in the Great Lakes.
• The Webster dictionarys definition of Seiches
  is
• The flow of periodically changing direction of
  the surface of a landlocked body of water (like a
  lake) that varies from a few minutes to several
  hours.

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Deaths during Floods

• Floods often result in death, especially along
  river banks and low-lying areas.
• Floods kill more Americans than any other natural
  disaster each year. You may be surprised but only
  6 inches of fast moving water can sweep a person
  off their feet and cars will float of move in
  only two feet of water.

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Red River Valley Flood

• The red river valley occurred in 1997 in
  Minnesota. That winter eight harsh blizzards hit
  Red River Valley. When the snow started to melt
  the river started to rise.
• The flood preparation was made for a 49 foot
  flood crest. The flood was actually 54.33 feet on
  April 22, 1997.
• Areas that were in immediate danger was evacuated
  on April 18th, people were evacuated from entire
  cities on the 19th.
• On the 24th the government officials started to
  let people back in dry areas.
• Most of the clean-up was done by the end of 1997
  but they were still building houses, basements,
  and other buildings in 2000.

The Red River flood crest emptied into Lake
Winnipeg on May 8th, 1997. This ended the largest
flood in Red River Valley ever recorded
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Mozambique, Africa Flood

• In Mozambique on March 3rd, 2000 an awful flood
  had destroyed three villages.
• Around 1 million people needed shelter, food, and
  medical care.
• Thousands of people remained on roofs and
  rat-infested trees.
• Rescuers had saved 12,000 people from flood
  waters after starving for a week.
• 15,000 remained in Save River Valley, stranded
  and nowhere to go.
• The government has estimated 1 million people
  have been displaced by floods since the beginning
  of February 2000.

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Bangladesh Flood

• Bangladesh is a country with many rivers.
  Flooding in this area is common and necessary so
  it could fertilize from deposits of fresh
  alluvium.
• Fresh alluvium is soil that is deposited by
  moving water.
• In the fall of 1974 flooding was extended over
  one half of the country and stayed this way for
  over a month.
• At least 1,200 people had died in the floods and
  27,500 died from diseases and starvation. 425,000
  houses were destroyed and destroyed agriculture.
  The cost of damages were 325.9 million in U.S.
• 36 million were effected by this huge flood.

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Nova Scotia Flood
This horrific storm dumped around 100 millimeters
of rain trough the Atlantic on Monday March 3rd,
2003. It was caused by melting snow, rain, high
tides, and freezing rain which caused streams and
rivers to clog and trees to break. Thousands of
people have had to bail out of their homes. The
overall damage for provincial roads and bridges
is estimated to be 10 million dollars. Nova
Scotias Transportation Department said 47
bridges have been destroyed or damaged by
flooding. Two hundred roads have been damaged in
the province as well. Major culverts were ruined
and oil tanks ripped from homes. Emergency
tenders are being sent out to get repair work
started as soon as possible. Unfortunately a
seniors couple died when that car got swept away
from a flooded road of Lahave River. This flood
was one of the worst floods Nova Scotia has had
in years.
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These are pictures of different parts of Nova
Scotia after the flood
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Northern California
Tunisia
Indonesia
Zambia
Southeastern Africa
Northern Australia
Western Australia
Brazil
Madagascar
This is where the latest floods have occurred in
the world. It was taken by NASA satellite.
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(No Transcript)
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Flood Insurance Rate Map

• A Flood Insurance Rate Map (FIRM) is a map to
  show flood risk zones and flood elevations.

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• LEGEND
• SPECIAL FLOOD HAZARD AREAS INUNDATED BY 100 YEAR
  FLOOD
• ZONE   A
• No base flood elevations determined
• ZONE   AE
• Base flood elevations determined
• ZONE   X
• Areas of 500 year flood areas of 100 year flood
  with average depths of less than 1 foot or with
  drainage areas less than 1 square mile and areas
  protected by levees from 100 year flood
• OTHER FLOOD AREAS
• ZONE   X
•  Area of 500 year flood areas of 100 year flood
  with average depths of less than 1 foot or with
  drainage areas less than 1 square mile and areas
  protected by levees from 100 year flood
• OTHER AREAS
•  ZONE   X
• Areas determined to be outside 500 year flood 
  plain
• ZONE   D
• Areas in which flood hazards are undetermined
• EXPLANATION OF ZONE DESIGNATIONS

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Flood Hazard Boundary Map

• A Flood Hazard Boundary Map(FHBM) is for an area
  and outlines the special flood areas but doesnt
  include and elevation information. It shows flood
  insurance risk zones. Its for 100-500 year flood
  areas.

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These are pictures of floods in Texas. It was the
worst flood since 1998 in Texas. 22 people were
killed
The NSDU extension service says
These are people from the red cross in China
reaching victims in their boat.
DURING A FLOOD Listen to the radio for further
information. Fill bathtubs, sinks and jugs with
clean water in case water becomes
contaminated. Bring outdoor belongings, such as
patio furniture, indoors. Move valuable household
possessions to the upper floors or to safe ground
if time permits. If you are instructed by
authorities, turn off all utilities at the main
power switch and close the main gas valve. Join
with neighbors and volunteers to put sandbags or
other protection in place. Stack sandbags away
from the outside walls of houses to prevent
floodwaters from entering. Do not attempt to walk
through moving floodwaters. If they are moving
fast enough, water one foot deep can sweep you
off your feet. Do not attempt to drive over a
flooded road. Turn around and go another way.
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A Video Clip
Click here
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Flooding

• As you can see flooding is not only a reoccurring
  natural disaster its also very dangerous!!
• Flooding is costly and threatening. This is no
  joke!!!

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Bibliography

• http//www.fema.gov/hazards/floods
• www.und.nodak.edu/dept/library/Collections/og1351.
  html
• http//wmo.ch/apfm
• http//www.antiflood.com
• www.canada.com/news/story.asp?id275CB01A-CDDC-47A
  OO-93/D5274D7244
• www.ssl.sabah.gov.my/clh/environment/flood/flood_e
  ffects.html
• www.na.fs.fed.us/spfo/pubs/n_resource/flood/toler.
  htm
• www.hydrology.com
• http//dmc.engr.wisc.edu/courses/hazards/BB02-06.h
  tml
• novascotia.cbc.ca/regional/servlet/View?filenames
  ns_floodcost20030402
• www.usatoday.com/weather/wfldfac.htmthree
• http//ks.water.usgs.gov/kansas/pubs/fact-sheet/f
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• www.hollandsentinel.com/stories/030400/new_slow.h
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• www.property-appraiser.lee.fl.us/GISDepartment/FI
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• www.savethechildren.org/press/pr_bangladesh.html
• www.personal.psu.edu/users/a/l/alal64/projects/ge
  og121/project5/firm_example.htm
• www.nws.noaa.gov/om/brochures/ffbro.htm