This is a horizontal stacked bar chart that examines the relationship between the frequency of fires and the season. Frequency is represented by the percentage of total number of fires that occured during the year for each season, and is shown by the size of each bar. The actual count of the fires is displayed over each bar. Bars are colored according to the season, as shown in the legend. The y-axis is represented by two different values, the year in which the fires occured, and the type of each fire. The user can switch which season appears along the left side of the graph, allowing them to better compare the values within that season along a straight line.
This chart can be used to examine the data and look for some correlation between the season and the number of fires, based on type. For example, one might think that outside fires are more common during summer due to the hot weather, or that structure fires are more common in winter due to the use of electrical appliances like heaters. These can be further supported or refuted by knowledge of the region in question, the Lone Mountain/USF area.
Beyond the scope of the original data processing, some additional processing was required for this visualization to best make use of d3 and its ability to stack bars. Processing involved manually creating columns for each season, and placing the calculated percentages (done with Tableau), in them, resulting in a row that contained the year, the fire type, the percentages and counts for each of the seasons (Spring, Summer, Fall, and Winter), and the total count for that year and fire type.
The switching functionality is based on the example here, as well as stacked bar chart examples found here and here.
The first prototype is the initial prototype submitted with the beta release. The second utilizes feedback on the first.