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Choropleth and Dot Mapping

 This week we explored choropleth and dot mapping. Choropleth is a thematic form of mapping that focuses on color units, whose color intensity is proportional to its corresponding data value. Dot mapping is also thematic. It uses either a proportional or graduated thematic symbol (like a circle), whose size increases due to its data value. Using ArcGIS pro, I analyzed the population densities of countries in Europe (person per square kilometer), as well as their wine consumption (liters per capita) to determine if there was a correlation between the two. In my choropleth map, I decided to use a natural breaks classification. I chose not to use Equal Interval because only 2 classes (with slight 3rd class) were represented in the map, and it looked like almost just one color in the lower range. The standard deviation classification appeared to be more diverse at first glance but was actually skewed to the top ranges. I was then between Quantile and Natural Breaks. While both these maps showed a good distribution and representation of data, I choose to go Natural Breaks. I choose Natural Breaks because the data didn’t have any big outliers (once the data was excluded) and a natural population density flow that could be split up every couple hundred naturally. I decided not to use Quantile classification because it made central Europe countries appear to have a higher population density then they actually had. The map looked more diverse, but inaccurately so.

For my proportional map, I chose to use the graduated method. I chose graduated symbols, as the proportional symbols overlapped too much and became one giant lump where symbols were they were not distinguishable. I do not think that classifying the data will skew the results, as there are no big outliers outside the set 5 classes. By classifying the data, I also am able to simply the data and make it more reader friendly and less overwhelming.

Figure 1: Choropleth map of Populations Densities of countries in Europe with Wine Consumption graduated symbology. 

I don't believe there is a simple correlation between these two factors as countries like Russia(low pop density, high wine consumption) and France/Germany (mid-high pop density, low wine consumption) contradict each other. 




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