“Other” Natural Disasters

Sink Holes, Floods, Fires, and Droughts

History of Fire

• Since the beginning of time man has depended on fire for survival.

• Fires have been used to heat homes, cook foods, disinfect instruments, and generate power.

• A fire occurs as the result of a chemical reaction (when two chemicals interact causing an explosion at the atomic level) they grow with the addition of oxygen.

Fires• Fires can be caused by lightning, volcanic eruptions,

droughts, hot weather, or even by humans• Fires can spread quickly with fuel from dead branches,

dry leaves, and rotting plants. During periods with little rain, a fire can spread even faster

Fires:• ground fires – burns grass and low lying vegetation• surface fires – burns trunks of trees as well as low

lying vegetation• crown fires – burn through the top of trees• brush fires – caused by people either on purpose or

accidently

FiresPROS

• keeps ecosystem in balance by clearing away dead and dying plants, making more room for new plants to grow

• scrub pines require fire to release their seeds so that new growth replaced the old, dead trees

CONS• damage natural

resources• destroy wildlife habitat• destroy beauty of the

environment• can lead into increased

soil erosionforest with periodical firesforest without periodical

fires

How to put fires out

• Because fires are a result of a chemical reaction there are several different ways to put out a fire– Water– Fire extinguisher– Fire blanket– Stop, drop, and roll– Sand

• Something VERY important to keep in mind is that fire’s need oxygen to survive so the LAST thing you want to do is blow out a fire or put it in front of a fan, you may make it bigger or spread it!

Drought• a drought can be classified as a long period of

time with dry weather that can cause serious problems such as crop damage and/or water supply shortages.

• severity of a drought depends upon the degree of moisture deficiency, the duration, and the size of the affected area

• In Florida, we can measure our degree of droughts by the levels of water in Lake Okeechobee

Droughts

• can cause farmers and people to be without a sufficient amount of water and can start water restrictions

• Crops and livestock can die without water• can increase risk of fire*Remember*-water makes up about 75% of the Earth’s surface-water makes up about 70% of our own body

The great dustbowl of the1930’s

During the 1930’s the western part of the United States suffered the greatest drought in the countries history. 70% of the land completely dried out and began to fly away like dust

Floods• Flooding happens during heavy rains, when

rivers overflow, when ocean waves come onshore, when snow melts too fast or when dams or levees break.

• Flooding may be only a few inches of water or it may cover a house to the rooftop.

• Floods that happen very quickly are called flashfloods.

FloodsPROS

• seasonal flooding can be an important source for lands

• floods can recharge water supplies in dams and underground aquifers.

• Floods can distribute large amounts of water and suspended river sediment over vast areas.

CONS• Excessive water can

destroy homes and endanger peoples lives

• People who are not properly prepared for floods or have an emergency plan risk their lives

Sink Holes• Sinkholes are common where the rock below the land surface is

limestone, carbonate rock, salt beds, or rocks that can naturally be dissolved by groundwater circulating through them. As the rock dissolves, spaces and caverns develop underground. Sinkholes are dramatic because the land usually stays intact for a while until the underground spaces just get too big.

Review

1. Fire is a result of _______________2. Fire needs _________ to survive3. This type of fire happens when you rub two

things quickly together4. You should use ____ to put out an open

flame fire

Review

1. A period of extremely dry weather ____2. Droughts put ____ in the atmosphere3. Droughts can kill (list 3)4. Droughts are caused by__________5. Droughts also cause water levels to __6. What is the lake that provides us with water?7. In Miami Dade we are under permanent

________

Review

1. Excessive rain or severe weather can cause ____

2. Floods can be good and bad, why?3. _________ are floods that happen quickly