Precipitation Maps

The isarithmic precipitation maps we learned how to produce this week are familiar to most people, and it was interesting to see how one is put together after having looked at them so many times on the nightly weather report. 

We worked with raster data from the USDA that was interpolated using the PRISM Interpolation Method devised by people at Oregon State University.  Using the Spatial Analyst Tool we created two maps showing annual precipitation in Washington state.  One map shows the data as a continuous spread of color in a spectrum.  The transition between one tone and another isn't perceptible.  The other map displays the data with hypsometric tinting which creates a stepped appearance to the color spectrum.  Hillshade Effect was added to both maps to display the map in relief. This week we also learned how to make contour lines, using the Spatial Analyst tool "Contour List" where the values for each index contour line were entered, and then had a choice of which map should have contours added to it.

 

 



This was a fun lab, and I can see how useful this technique will be going forward.