Environmental Hazards

Objectives

At the end of the session the students should be able to:

1.  Describe the natural calamities/natural environmental hazards and man-made calamities.

2.  Enumerate the effects of environmental hazards.

3.  Discuss the natural environmental hazards occurred in the Philippines.  

Environmental Hazards

•       Any situations which poses a threat to the environment.

Types of Environmental Hazards

1. Natural Hazards

2. Man-made Hazards

Natural Environmental Hazards

Avalanche

• a large mass of snow in motion down the mountainside.

Lahar

•       Involves a large amount of volcanic material sliding down the side of the volcano.

Earthquake

•       Result of a sudden release of energy in the Earth's crust that creates seismic waves.

Sinkholes

• A localized depression in the surface ground

Volcanic eruptions

•       An active volcano that releases its power.

Flood

•       Result of prolonged rainfall from a storm, or rivers which swell from excess precipitation upstream.

Limnic eruption

•       Rare type of natural disaster in which CO2 suddenly erupts from deep water.

Whirlpool

•       Swirling body of water usually produced by ocean tides.

Maelstrom

•       Maelstroms are a large tidal whirlpool.

Tsunami

•       The word comes from Japanese words;

▫       "tsu" meaning harbor

▫       "nami" meaning wave

▫       tsu+nami=harbor wave

•       Tsunami can be caused by undersea earthquakes or by landslides.

Blizzard

•       A blizzard is a severe winter storm characterized by low temperatures, strong winds, and heavy blowing snow.

Hailstorm

•       A thunderstorm that produces numerous hailstones.

Ice storm

•       A weather event in which precipitation falls as ice.

Drought

•       An acute shortage of water and crop failure that results when the average rainfall is very less than the normal.

Cyclonic storms

•       Hurricane

•       Tropical cyclone

•       Typhoon

•       It is caused by evaporated water that comes off of the ocean.

Tornado

•       Tornadoes are violent, rotating columns of air.

•       Waterspouts are tornadoes occurring over water.

Heat wave

•       Extreme and unusual increase in the  temperature.

Wildfire

•       An uncontrolled fire burning in wild land areas.

•       Common causes of wildfire

▫       Lightning

▫       Drought

▫       Man-made

Man-made Environmental Hazards

•       Deforestation

•       Mining

•       Overgrazing

•       Overcultivation

Deforestation

·      clearance, clearcutting or clearing is the removal of a forest or stand of trees from land which is then converted to a non-forest use.

Mining

•       Mining is the extraction of valuable minerals or other geological materials from the earth.

Types of Mining

1. Surface mining

2. Sub-surface

Overcultivation

•       Refers to growing of too many crops, year after year on the same piece of land.

•       Damages the soil structure and reduces the soil fertility.

Overgrazing

•       Overgrazing occurs when plants are exposed to intensive grazing.

Effects of Man-made Environmental Hazards

1. Erosion

2. Formation of sinkholes

3. Loss of biodiversity

4. Soil contamination

5. Water contamination

Effects of Environmental Hazards