Does it rain more than it used to in Western Oregon? .
For today's in class work we will be working with spatial and temporal data sets which are quite noisy. Particularly, you have monthly rainfall totals for the following six locations in Oregon from the period 1950 - 1999.
There are many facets of what you can do with this data and this data set represents a good example how you would interrogate data.
Use the Z-test here (use excel to calculate averages and standard deviations or use the normal distribution tool in the above link)
Example questions:
1. Is there a tendency for rainfall to have increased in the latter part of the 20th century compared to the earlier part? In particular, is the mean rainfall during the decade of the 90's significantly higher than would be expected?
2. Look for evidence of any cyclical behavior in the data on decade long timescales. This is best done by comparing "waveforms" for the data (which can be done qualitatively). That is, are each of the six sites described by a similar kind of waveform are does each site appear to be unique.
To do this, we can use the moving average feature in Excel.