GIS5007 Module 6: Isarithmic Mapping

We're nearing the finish line of the Cartography course. It always shocks me how fast it goes, but here we are at Module 6 on Isarithmic Mapping.

Isarithmic mapping is all about depicting 3D spatial data in a 2D space. In this lab, we focused on continuous and hypsometric maps of Washington state's annual precipitation from 1981 to 2010. Continuous tone maps emphasize smooth color gradations to represent the data, while hypsometric tints are more distinct, with clear groupings of data range values. Because of this, hypsometric is technically less precise than continuous in depicting the data since it represents values in ranges. So, depending on the size of the area you wish to cover and your mapping needs, continuous tone or hypsometric tint may be better suited. For instance, if I needed a general, easily readable map of trends, I'd rely on hypsometric maps. However, if I needed precise pixel values, I'd stick to continuous-tone maps for data fidelity.

As you can see in the hypsometric map below, I created a map showing annual precipitation in inches of the entire state of Washington in that 30-year period. The Int geoprocessing tool was used on the annual precipitation raster, which truncates each cell value to an integer. Then we manually classified the data into 10 classes and applied the precipitation color scheme to them. Additionally, contour lines were created at each class break (10, 20, and 40 contour value increments) to accentuate the precipitation across elevation.

I didn't do too much when it came to designing this map. Since symbology was more guided, given that we were creating a hypsometric map of precipitation, we didn't experiment with symbols or colors this time. Funny enough, the topic of the week was related to weather, and I was feeling under the weather this past week. Because of that, my layout isn't as decorated as I would have liked. If I had more time and energy, I'd try to lean into the rain-and-cloud theme I was alluding to with some of the design elements I made. To ground the state of Washington, I brought in additional external data from the US Census Bureau to create a small inset of the USA, making it clear that I was referring to Washington state.

Raincheck on Washington: An Annual Precipitation Analysis from 1981 to 2010. This isarithmic map used hypsometric tinting to showcase the data in 10 distinct classes, using the precipitation color scheme. Included are also contour lines at each class break (10, 20, 40 contour value increments).