Spatio-temporal analysis on built-up land expansion and population growth in the Yangtze River Delta Region, China: From a coordination perspective

Revealing the temporal and spatial changes on built-up land expansion and population growth is extremely important for city's sustainable development. Although the differences in land and population growth have been examined, the range and the influential factors of such a gap have not been fully studied. In this research the ratio of the land expansion rate to the population growth rate is used as coordination degree to identify the trend of the "land-population" coordination with the case study of the Yangtze River Delta Region, China by means of spatial analysis and regression. Results indicate notable built-up land expansion and demographic change in the research area. The coordination degree increased from a value of 2.28 in Period I (1990-2000) to 3.12 in Period II (2001-2014), further away from the ideal value (i.e. 0.8-1.4). Overall, the coordination level in central region of the study area is better than those of the North and the South. Regression analysis shows that neighborhood and per capita GDP are two significant influential factors of built-up land expansion and population growth in both periods, and that the impact of "neighborhood" has intensified over time. These findings demonstrate that socioeconomic situation of geographically neighboring cities contribute a lot to the coordinated development of the local population and land.