Results

Impact on human settlements

The following maps show the impact of volcanic hazards on human settlements near Mt. Rainier.

Map of lahar hazard

Map of pyroclastic surge hazard

See a simulation of spreading lahars from Mt. Rainier.

Discussion

Factor Weighting

In the two MCE's (used to detemine lahar hazard and pyroclastic surge hazard), factors were wieghted using a combination of common sense and educated guesses. For example, pyroclastic surges fade rapidly with distance from the source, therefore the distance factor was wieghted relatively heavily in this analysis. Conversely, lahars can travel a very long distance, so the distance factor was given a low wiehgt in the lahar hazard assessment. Further research could include changing the relative weights of the factors and performing a sensitivity analysis to determine the most appropriate combination of factors.

Implications for public policy

Clearly, this analysis could be very useful for community disaster planners in the affected area. GIS users can easily overlay any number of layers onto the hazard assessment images, and determine hazard ratings for roads, campgounds, bridges, and other infrastructure. This could have implications for land use planning, insurance coverage, and tourism restrictions near Mt. Rainier. These other topics are beyond the scope of this analysis; I have limited my impact analysis to cities and small towns in the study area.

Limited spatial coverage

The study area for this analysis covers an area northwest of Mt. Rainier. Due to the time involved in importing and preparing the data, as well as the very large file sizes, I did not include the entire Mt. Rainier watershed. A subsequent analysis might include the entire watershed, all the way to the coastal city of Tacoma and the surrounding communities.