GIS4007 - Module 6 - Isarithmic Mapping

For this module, we explored the principles and techniques of isarithmic mapping; a method used to visualize continuous spatial phenomena like elevation, temperature, and precipitation. The goal for this assignment was to learn how to represent continuous raster data using hypsometric tints, contour lines, and hillshade effects to create a well designed map. We also covered the use of PRISM interpolation method, spatial analyst tools, and key cartographic design principles to design our map.

The map I created for this module shows the average annual precipitation across the state of Washington state using isarithmic symbology. The base precipitation data was provided by the USDA Geospatial Gateway and represents a 30-year climate average, interpolated using the PRISM (Parameter-elevation Regressions on Independent Slopes Model) method. This model accounts for elevation, topographic orientation, and coastal proximity, which makes it especially effective in mountainous and coastal regions like the one in this map. I applied hypsometric tints to categorize precipitation into 10 distinct classes which are symbolized with a clear precipitation color ramp. Contour lines were overlaid onto the data to show the changes in precipitation levels across the landscape.

One of the challenges was making sure the hillshade effect complemented the precipitation data without overwhelming it this was accomplished by adjusting the transparency and color schemes. I also learned how to turn off the certain background information like the names of bordering states by adjusting the vector tile layer. This ultimately allowed me to keep background map visuals without crowded labels. 

This lab required artistic thinking on how best to symbolize continuous data and reinforced the importance of thoughtful map layout and visual hierarchy. Overall, I feel I have improved my confidence in using spatial analyst tools and learned how I can best visualize complex environmental patterns.