Natural Disaster

5 Natural Disasters• Drought • Flood • Forest Fire• Tornadoes• Volcanic Eruption

Drought

What is a Drought?

• Drought is a period or condition of unusually dry weather within a geographic area where rainfall is normally present. During a drought there is a lack of precipitation. Droughts occur in all climatic zones. However, its characteristics vary significantly from one region to another.

Causes of D

rought

• We already know that a drought occurs when not enough rain falls to the ground.• Or droughts occur because water vapor

is not brought by air currents to the right areas at the right times.

Effects of Drought

Environmental - Increased desertification - Damage to animal species

- Reduction and degradation of fish and wildlife habitat - Lack of feed and drinking water - Disease - Increased predation. - loss of wildlife in some areas and too many in others - Increased stress to endangered species - Damage to plant species - Increased number and severity of fires - Wind and water erosion of soils

Social - Food shortages

- Loss of human life from food shortages, heat, suicides, violence - Mental and physical stress - Water user conflicts - Political conflicts - Social unrest- Public dissatisfaction with government regarding drought response - Inequity in the distribution of drought relief - Loss of cultural sites - Reduced quality of life which leads to changes in lifestyle - increased poverty- Population migrations

Flood

What is a Flood?

• A form of natural disaster when there is more water than the lakes, rivers, oceans, or ground can hold

Causes of Flood

• Too much rain• Excessive melting of snow• Too much water for the ground to

absorb water• Ice or other objects block the flow of

the river

Effects of Flood

• Damage property and homes• Kill people and animals• Communities in flood zones must be

rebuilt with proper flood controlling equipment

Forest Fire

What is a Forest F

ire?

• A forest fire is a natural disaster consisting of a fire which destroys a forested area, and can be a great danger to people who live in forests as well as wildlife. Forest fires are generally started by lightning, but also by human negligence or arson, and can burn thousands of square kilometers.

Causes of Forest Fire

• Extinguishing fire improperly.• Burning candles in tents.• Burning crackers in the forest.• Parking cars in the forest.• Throwing industrial waste in the forest.• Lighting cigarette in the forest.• Accumulating dry leaves and bushes at

one place.

Effects of Forest F

ires

• Destroys in the vegetation of plants.• Destroys in the vegetation of

animals.• Destroys the water of lakes, rivers,

ocean and seas.

Tornadoes

What are Tornadoes

• A tornado is a powerful column of winds spiraling around a center of low atmospheric pressure. It looks like a large black funnel hanging down from a storm cloud. The narrow end will move over the earth, whipping back and forth like a tail.

Causes of Tornadoes

• Tornadoes are formed when hot air and cold air are mixed.• The clouds grow larger and larger.

Finally, a thunderstorm is brewed up with a strong updraft.• The moisture in the warm air rises and

condenses into large clouds.

Effects of Tornadoes

• Tornadoes can make People die.• The tornado can destroy a lot of

homes, stores, and much more.• It can make serious injuries.

Volcanic Eruption

What is

Volcanic Eruption

• When a part of the earth's upper mantle or lower crust melts, magma forms.

Causes of Volcanic

Eruptions

• Low water, high silica (very viscous) - pasty lava - often building domes.

• Low water, low silica - runny lava flows (not viscous).

• High water, low silica(not viscous) - fountain of runny lava.

• High water, high silica (very viscous) – explosion.

Effects of Volcanic

Eruptions

• Volcanic Ashes• Debris Avalanches, Landslides, Tsunamis• Blast • Lava• Types of Lava Flows• Gas

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