Tunchang County in context: Street-network sprawl trends

Tunchang County in context

2.83.54.24.9<19751976–19901991–20052006–2020SNDi of street additions
2.83.54.24.9<19751976–19901991–20052006–2020SNDi of entire street network
Tunchang CountyHainan (Region)China (Country)

The chart above shows SNDi trends for new street additions (left panel) and the entire network (right panel), with Tunchang County plotted against Hainan and China. The SNDi of new construction in Tunchang County peaked in 1991-2005, compared to Hainan which followed a zig-zag trend with an overall increase and China which followed a zig-zag trend with an overall increase. Most recently, Tunchang County's incremental SNDi fell from 4.72 to 2.39 between 1991-2005 and 2006-2020. In terms of the aggregate network, Tunchang County ranked 6th out of 17 cities in Hainan and 1235th out of 1843 in China as of 2020.

New Street Additions (2006–2020)

SNDi value
2.39
Rank in China
447th of 1843
Rank in Hainan
2nd of 17

Entire Network (Aggregate)

SNDi value
3.28
Rank in China
1235th of 1843
Rank in Hainan
6th of 17

Rankings go from most connected to most disconnected — rank 1 is the most connected.

What about similarly populated cities?

36912<19751976–19901991–20052006–2020SNDi of street additions
36912<19751976–19901991–20052006–2020SNDi of entire street network
Tunchang CountyShihengPelaihari

In new street additions, Tunchang County built increasingly disconnected streets from 1975 through 1991-2005, then improved, while Shiheng fluctuated in its street-construction patterns and Pelaihari built increasingly disconnected streets over time. For the full network, Tunchang County grew more disconnected from 1975 through 1991-2005, then improved, while Shiheng grew more disconnected from 1975 through 1976-1990, then improved and Pelaihari became progressively more disconnected. Notably, Tunchang County had a more connected network than Pelaihari in 1975 but the two have since reversed their relative ranking.