Spatial pattern evolution of rural settlements from 1961 to 2030 in Tongzhou District, China

Rural settlement is an important land use type in China due to the country's large rural population. In recent years, China's social economy has undergone dramatic transformation, and the land use pattern of rural settlements has also significantly changed. Against this background, it is important to reveal the evolution rules of rural settlements to provide references for rural settlement rearrangement. Based on interpreting high-precision military satellite remote sensing images, we selected Tongzhou District of Beijing as a case to discuss the evolution process of rural settlements during 1961-2015. Tongzhou has a history of rural settlement construction for more than 2000 years and will face rapid changes in rural settlement patterns due to the new urbanization policies. The land transformation model (LTM) was employed to simulate the spatial expansion of rural settlements in 2030. The results showed that the number of rural settlement sites in Tongzhou continuously decreased during the past 50 years, with a total decrease by 43.30 %, whereas the total area continuously increased during 1961-2015 (146.64 %). The spatial pattern of the rural settlements was regularized continuously, but the spatial distribution of density varied in different stages. In total, spatial density first presented a decreasing trend, followed by an increase. For over 50 years, there were mainly four evolution modes for the spatial distribution of rural settlements in Tongzhou, namely the extinction, the diffusion, the infilling, and the merging mode. The simulation results obtained by the LTM showed that the rural settlements of Tongzhou all expanded, albeit to varying degrees, and that their expansion mostly followed the diffusion mode, based on the existing rural settlement sites.