Table 1. Index system of socio-economic-ecological environment factors in the process of urbanization.

Sub-system		Index & Direction	Effect
The integration value of Economic (E)	Economic structure	Secondary industry proportion of GDP (%)	+
		Tertiary industry proportion of GDP (%)	+
		Import and export trade proportion of GDP (%)	+
	Economic efficiency	Per capita annual income	+
		GDP per capita (yuan/person)	+
		Per capita industrial output value (yuan/person)	+
The integration value of Society (S)	Population and land	Urban population	+
		Per capita road area (sq.m/ person)	+
		Urban population density (person/Km2)	+
		Built-up area (square kilometers)	+
	Demographics	Non-agricultural population as a percentage of total population (%)	+
		Number of doctors per 10,000 people	+
		Number of college graduates per 10,000 people	+
		Percentage of employees in the tertiary industry	+
The integration value of Ecology (E)	Environmental pressure	Industrial wastewater discharge (t)	-
		Sulfur dioxide emissions (t)	-
		Industrial waste production (t)	-
	Environmental status	Per capita cultivated area (sq.m /person)	+
		Per capita land area (sq.m / person)	+
		Per capita water supply (t/person)	+
		Per capita green area (m2/person)	+
		Green area coverage in built-up areas	+
	Environmental response	Proportion of industrial wastewater that meets emission standards	+
		Comprehensive utilization ratio of industrial solid waste	+
		Environmental protection investment as a percentage of GDP (%)	+

Notes.

^a“+” represents positive effect. “-” represents negative effect.