Geomorphic and Hydrologic Controls on Urban Expansion from 1992 to 2013 across North-East China

The scale of urbanization is well-acknowledged. However, little is known about its spatial and temporal dynamics. The organization of human settlements is influenced by geomorphological, hydrological, climatic and geographic drivers, resulting in inhomogeneous distributions across the globe (i.e. specific sites show very high human density levels and other regions are almost uninhabited). Natural resources availability and environmental criticalities highlight the relevance to forecast how human settlements will be distributed in the near future, especially in a climate change perspective. Here we analyse human settlements dynamics in space and time in an area close to Beijing in the Northeast of China. We employ remote sensed nightlight images available from 1992 to 2013 as a proxy of human population and urbanization level. We develop a spatially explicit probabilistic modelling framework to simulate human settlements dynamics (i.e. city growth). Combined effects of hydrologic and geomorphic factors (rainfall, temperature, elevation, slope, distance to the river network and to the shoreline) as well as the proximity to urban areas are examined as key drivers of urban expansion. Starting from the urbanization level in 1992, the model is capable of reproducing the observed urban growth in every year in the study period, as also confirmed by the probability distribution of the size urban clusters. The model can also effectively simulate future urban growth scenarios, thus providing valuable information on where human settlements will be located in future and how urban expansion will evolve.