California Dreamin’

The Natural Hazards of California

When you think of California

Do you think…

OF THIS?

OR THIS?

MUDSLIDES EARTHQUAKES FLOODS, FIRES DROUGHT, STORM SURGES.LANDSLIDES

Mudslide/ Mudflow

DEFINITION:

• A general term for a mass-movement landform and process characterized by a flowing mass of fine-grained earth material with a high degree of fluidity. The water content may range up to 60%

Causes

• short period of high-intensity rainfall during the summer dry season

• thaw of the winter snow pack.

• Wildfires followed by thunderstorms or heavy rain

• most likely to occur on slopes greater than 65 percent

Wildfires

• Definition

• An uncontrolled fire that spreads though vegetative fuels, exposing and possibly consuming structures

Causes

• Build up of vegetation fuel due to dry climate

• Santa Ana Winds

• Sparks from human source

• Controlled burning

• Arson

Floods

• Definition

An overflowing of a body of water onto normally dry land.

Causes•Winter Storms

•El Nino

•Deforestation

•Poorly maintained defences

Earthquakes

• Definition

• An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves.

Causes

• A Network of over 300 active faults (e.g. San Andreas)

• About 10,000 quakes each year rattle Southern California alone, although most of them are too small to be felt

• 5 major earthquakes in the last 100 yrs including SF - 1906

Drought

• Definition

• A drought is a prolonged, abnormally dry period when there is not enough water for users' normal needs

Causes

• Issues with El Nino

• Lack of rain

• Constantly high demand from urban populations

• Needs better infrastructure.

• Temperature

Storm Surges

• Definition

• A rise above normal water level on the open coast due only to the action of wind stress on the water

Causes

• Strong Winds

• Rising sea levels

• Spring/ High tides

Landslides

• Landslides often accompany other natural hazards and are often more damaging and deadly than the triggering event

• Human activities and population expansion are major factors in increased landslide damage and costs.

Causes

• Earthquakes

• Wildfires

• Storms

• Man induced

• Rainfall

Fog/ Smog

• Definition

• a mixture of pollutants, principally ground-level ozone, produced by chemical reactions in the air involving smog-forming chemicals.

Causes

• burning of petroleum-based fuels

• consists of over 100 chemicals

• Major producers of smog include automobiles, fires, waste treatment, oil production, industrial solvents, paints, and coatings