Choropleth maps of the United States :
Comparison with population and housing
In this mapping, the data of over 250,000 people among data of population in 2007 is shown with symbolized red dots. Furthermore, the population change, housing unit change, and vacant housing change are shown 3 different choropleth maps. As you can see the exhibit 1, the increasing number of population resulted in increasing number of housing units. Therefore, the both choropleth maps have a similar pattern of color gradation (larger number has darker color). Additionally, the exhibit 3 represents vacant housing units, which pattern is closely related to the number of housing units.
Exhibit 1 and 2. Population change and Housing unit change in the United States. Exhibit 3. Vacant housing change in the United States
Green Vehicles of King county
To compare two notable green vehicles: Walking, and bicycling, I took the King County, Washington as a reference county which includes Seattle. The number of total population who prefer to walk for commuting is four times greater than that of bicycling.
However, the average area of distribution is quite similar in both two means except the Snoqualmie Valley and Enclaw Plateau (hard to get to by bicycling). The downtown of Seattle represents most green vehicle use due to the high density and traffic.
Walkability in Pittsburgh
Based on the location of green playground, this map investigated the walkability of surrounding area. Aerial ortho-imagery photo helped to understand the playground area and condition of surroundings.