posted on 2022-12-29, 18:08authored byShen Qu, Ke Yu, Yuchen Hu, Changchang Zhou, Ming Xu
Cities have been envisioned as biological organisms as
the integral
part of nature’s energy and material flows. Recent advances
in urban scaling research have uncovered systematic changes in socioeconomic
rates and infrastructural networks as urban population increases,
providing predictive contents for the comparison between cities and
organisms. However, it is still unclear how and why larger and smaller
cities may differ in their per capita environmental impacts. Here,
we study scaling patterns of urban energy, water, and waste flows
as well as other relevant measures in Chinese cities. We divide cities
into different groups using an algorithm that automatically assigns
cities to clusters with distinct scaling patterns. Despite superlinear
scaling of urban GDP, as predicted by urban scaling theories, resource
consumption, such as the supply of electricity and water, and waste
generation, such as wastewater and domestic waste, do not show significant
deviations from linear scaling. The lengths of resource pipelines
scale linearly in most cases, as opposed to sub-linearity predicted
by theory. Furthermore, we show two competing forces underlying the
overall observed effects of scale: a higher population density tends
to decrease per capita resource consumption and infrastructure provisions,
while intensified socioeconomic activities have the opposite effect.