Introduction

This chapter is still under construction. The headings are probably accurate, but the details, images, and videos are missing.

This book will look at natural hazards in a STP approach. That’s Spatial, Temporal, and Physical. For nearly any particular event, even your college classes, you know the location and timing of the event before you know how it happens. Travelers going to Rome in the 1500s must be at least somewhat concerned about the possibility of earthquakes because they were known to happen there, even if know one knew the physical process causing quakes.

Spatial

Distribution

Hazards are not evenly distributed around the world. Some places have earthquakes, but not blizzards. For some places five inches of rain in one day is normal but in a different location the same five inches is a once in a lifetime event, or even more rare. We need to know where different hazards exist so we can have the correct preparation and materials in the correct locations to save lives and property.

This course looks at natural hazards around the world, the country, and the state and local regions. There are broad, general processes that apply to the global issue, but some hazards have regional and local variation. It’s still an earthquake, but different types of plates and movement are involved.

Think of the form, the shape, of the affected area and how that changes depending on the scale of investigation. A world map that fits on a page in a text book may show a tornado as a dot, but the TV station near the tornado will probably show a line where the tornado destroyed homes. The region where a type of hazard is most prevalent could be the equivalent of several US states, thousands of square miles, or more. But an individual event can range from hundreds of miles long in a 9+ scale earthquake to  a few hundred meters in a flash flood or tornado.

Diffusion

Some hazards are abrupt in both space and time.

Does the event move progressively down a line? Some floods do this. Does the energy more out from a central point? Some earthquakes might have some of this characteristic.

Does the impact of the event have and abrupt edge? Your home may be perfectly fine across the street from a home that was destroyed by a tornado. However as you move farther away from an earthquake epicenter, there’s progressively less destruction.

Temporal

Frequency

Frequency refers to the number of occurrences of an event of the same magnitude over a period of time.

Magnitude

Magnitude refers to the size of the event. Usually we are interested in measuring a physical component such as wind speed, wave height, or ground movement. Sometimes we refer to loss of life or property.

Physical

Which material is involved

How does energy change form (Potential, Kinetic)