Lab 8

This week’s lab was an exercise in interpolation. Using data from the LADWP, I used various interpolation methods to compare and assess precipitation levels for the county’s current season and the seasonal average. The most complex and time-consuming part of this lab was definitely compiling the data from the website into a spreadsheet. The following spatial analysis was straightforward and rather simple.

The first step was compiling the name, longitude, latitude, precipitation to date, and average precipitation of each station into a spreadsheet. This was then inserted as a layer in ArcGIS and the spatial analysis was made from this data. With the Los Angeles County as a spatial analysis mask, this data was added to multiple data frames. I interpolated the average and season to date precipitation data using the two different types of splines and two different powers of the inverse distance weighted method.

             This final out put includes the splines of both and the IDW of both but also the difference in the precipitation to date and the average precipitation using both a spline and IDW. Although each is relatively easy to do and as easy as the other, it is difficult to determine which method is most effective and accurate for this type of data. The differences in both methods are noticeable but it’s hard to determine which is more accurate. By doing more spatial analysis and more interpolations, I hope to gain more experience and learn more about these different methods.