The coupling characteristics of population and residential land in rural areas of China and its implications for sustainable land use

Understanding the changes and coupling characteristics between rural population (RP) and rural residential land (RRL) provides a theoretical basis for sustainable rural land use. Based on the index of human-land coupling development, this study analyzed the spatial-temporal characteristics and coupling types of RRL and RP on the levels of China's national and prefectural cities by using the data of official land use survey and demographic statistics from 2009 to 2016. Results showed that (a) China's RP is declining at an average annual rate of 2.07%, and the RP in most cities decrease from -3.33% to -1.20%. (b) The area of RRL in China constantly increased at an average annual rate of 0.56% and that of most cities has also maintained growth, with only 11.76% of cities that declined. (c) The per capita RRL in China increased from 267.96 m(2) in 2009 to 325.58 m(2) in 2016. The relationship between the RRL and RP in China was uncoordinated with a coupling type of G (rapid decline in RP and increase in RRL). The coupling types of most cities were also the uncoordinated type of G, and only less than 10% of cities had a coordinated type (Types B, C, D, and E). The results indicated that the coupling relationship between RP and RRL in China is decoupled and has obvious spatial heterogeneity, which could provide scientific support for optimizing land resources and coordinating human-land relationship in China's rural areas.