Cities are generally built on the hub and spoke model. The downtown area is highly commercial for retail and office while residential neighborhoods surround it. As cities grow and the need for commercial space goes up, residences closer to downtown are converted and homes move farther away. When cities hit geographic barriers, they start to build up like in Hong Kong or New York City. However with no such natural barriers, they generally spread out in an ever increasing radius and eventually their growth plateaus. We then see the rise of sister cities nearby that can pick up the overflows. Such models have had great success as they encourage a congregation of talent, creating melting pots for innovation, culture and social reforms. And infrastructure for the greatest cities was built far ahead of the traffic that now plows through them. The hub and spoke model has also seen quite a few disadvantages, more so during the pandemic. Dense downtown populations during peak hours, massive heat sinks, heavy congestion both in traffic and on public transportation, and ever increasing commute times have created unsustainable lifestyles for families. It felt like cities were for singles who crammed in with 3 others in threadbear apartments while trying to make their mark professionally. However, families could not afford to continue in such urban jungles. And the pandemic driven exodus from mega cities (LA, SF etc) towards small to mid-size areas confirmed this. Post-pandemic, fresh singles will again arrive in those mega cities and try their best to hang on for as long as they can, feeding the fenzy that we have already seen. Knowing what we do, we would like to apply the lessons learnt towards building more sustainable infrastructure in growing cities. Of the top 100 growing counties in the US, Mecklenburg county has consistently grown by more than 2% each year, leading to its population doubling in less than 30 years. This county of 1.1 million has the potential to continue growing for a few reasons:
- it currently has an abundant energy source owing to a large nuclear power generation plant that serves retail customers in two states with electricity bills that are 20% below the national average
- it lacks large geographic or climate risk barriers like coast lines, major rivers or hurricane corridors
- it resides close to a large airport (ATL is a 4 hour drive)
There are however a few issues that need to be addressed to ensure the city adapts for its future:
- the county’s climate is getting wetter (more rainfall) and drier (rising temperatures)
- housing has spread rapidly over the past few decades and breached Charlotte city limits
- 60% of the state’s energy consumption is in its residential and transportation sector while a majority of this energy is produced from non-renewable sources
In an effort to go green, the local government should consider leveraging its urban infrastructure to achieve net-zero emissions, and encouraging its citizens to adopt a greener lifestyle. The following ideas begin to take shape:
- decongesting the city center by building additional hubs around it. This reduces the energy consumed in long commutes.
- incentivizing home owners to invest in rooftop solar, building mounted wind turbines, rainwater harvesting and planting more trees
- converting county owned land into parks/water bodies to capture urban heat Extensive analysis was undertaken using Landsat and Sentinel satellite images for 2019 along with US Census estimates. All results are benchmarks as high limits have been applied (eg: only 20% of households and within 2.5 miles of the new urban hubs would reroute to the new location, only 5% of household rooftops can capture solar energy and only 1% of the entire county can capture wind)
Files available:
- Data Analysis: details on the results of this analysis
- PDF map: spatial summary of this analysis
- Web map: https://arcg.is/1SKLez0 (online maps made available for additional details)
- Model: the process flow (viewable in ArcMap)
Sources:
- Mecklenburg county Electricity rates: https://findenergy.com/nc/mecklenburg-county-electricity/
- County Climate: https://usafacts.org/issues/climate/state/north-carolina/county/mecklenburg-county
- NC state Energy profile: https://www.eia.gov/state/?sid=NC
- Landsat imagery: https://earthexplorer.usgs.gov/
- Sentinel imagery: https://scihub.copernicus.eu/dhus/#/home
- US Census Housing 2019 estimates: https://www2.census.gov/programs-surveys/popest/tables/2010-2019/housing/totals/CO-EST2019-ANNHU-37.xlsx
- Solar & Wind Energy shapefiles: https://www.nrel.gov/gis/renewable-energy-supply-curves.html
- Calculating Wind energy: http://zebu.uoregon.edu/1998/ph162/l11.html
- KWh in gasoline: https://www.jdpower.com/cars/shopping-guides/what-is-kwh-per-100-miles