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