It’s no secret that many communities are changing. Some are growing and some shrinking. How can you get a sense of what the future holds for your community? The County of Marin is working to provide visual representation in the form of CMap Charts, which show population changes over time by census tract. These charts help us visualize how our communities are evolving and allow us to start thinking about how we want them to look like in 10 years or more from now.
I’m the data nerd at Marin County, and I love using C Map Charts to explore population changes in my community. There are five charts you can use for free on our website:  Population Change by Census Tract (1990-2010), Hectares of Land Converted or Added per Year, New Housing Units Built Per Year (1992-2009), Households with No Children under Age 18 Living at Home Per Year (2001-2011) and Dwelling Unit Conversion Rate per Census Tract from 1990–1999 to 2000–2008.
If you want more information about how we provide this visualization tool, please email me ([email protected]). If you’re an analyst who has a research project that could benefit from C Map Charts, please get in touch.
What makes C Map a powerful tool for understanding population change is that it’s interactive and customizable, so you can focus on one community or compare multiple communities at the same time. For example, if I want to see how Marin County compares to other coastal counties between 1990 and 2010: Â
I open up C MapCharts by selecting “population” from the drop-down menu. Then I choose my county of interest (Marin) from the left side of the screen next to “Change.” The right panel shows me all five charts – Population Change by Census Tract (1990–2010), Hectares of Land Converted or Added per Year, New Housing Units Added per Year, Population Change by Housing Unit (1990–2010), and Percent of Total County Area in Permitted Development Areas.
I can hover the mouse over each chart to see more detailed information about what it represents like which census tract is shown on a map or how many housing units were added between 1990-2010. I also get an overview of my county’s population change from 1990 – 2010 broken down by housing unit with interactive maps showing where new development has been approved. Â C Map Charts let me explore Marin County’s population changes at different levels for any period that interests me making this tool very powerful and user friendly!
Resources: Â C MapCharts are designed specifically for use with Google Earth and are available for download here:
The future of America’s cities depends on investing in public transportation. New York City is growing rapidly but still has a lot more people living near transit stations than car dependent communities across the U.S. This heatmap from CMAP shows how close residents live within walking distance of rail or bus service lines with different levels of frequency.
New York City residents are more likely to use public transit because of the city’s density and robust rail service.  C Map Charts can help planners understand where investments in new transportation infrastructure could have the most impact on a community’s development patterns over time, or how different levels of investment might affect population densities across an entire region.
Resources: CMAP maps show how close residents live within walking distance of bus or rail lines with different levels of frequency.”
The future of America’s cities depends on investing in public transportation. New York City is growing rapidly but still has a lot more people living near transit stations than car dependent communities across the U.S. This heatmap from CMAP shows how close residents live within walking distance of bus or rail lines with different levels of frequency.
This map from the Center for Neighborhood Technology (CNT) illustrates where cities across America are growing, and highlights that public transportation investment can help shape developments patterns. CNT’s analysis also finds a significant correlation between transit proximity to employment hubs and housing density; in other words, people who live near stations tend to work nearby as well. This means investing in public transportation is not only good for our future—it’s good for current commuters too!
Conclusion:
I’m excited about the County of Marin’s work on C Map Charts. These charts give us a visual representation of how our communities are changing over time and allow us to start thinking about what we want them to look like in 10 or more years from now. If you’re interested, please contact me for more information on this project!
