“…The four predominant components were extracted from the 17 original indices with the varimax rotation method; the first four principal components can explain 81.861% of the total variance (Table 2). Based on the rotated component matrix, component I primarily describes the urban-rural social development degree, which consists of the consumption of chemical fertilizer, per capita cultivated land area, non-agriculture population proportion, percentage of rural nonfarm payrolls, average number of hospital beds per 100 inhabitants, and persons receiving lowest cost-of living per 100 inhabitants with 29.125% of the total variance [3,40,44,45]. Component II, which is composed of the per capita public-budgetary expenditure, per capita fixed-asset investment, per capita domestic product, green coverage rate of built-up area and highway net density, is related to the degree of economic development and accounts for 27.397% of total variance [41,46,47].…”