Settlement changes after peak population: Land system projections for China until 2050

Yuan Wang,Jasper Van Vliet,Niels Debonne,Lijie Pu,Peter H Verburg

doi:10.1016/j.landurbplan.2021.104045

Abstract

China has experienced unprecedented urbanization in the past few decades, fueled by population growth, economic development, and rural to urban migration. In the future, economic growth as well as rural to urban migration is expected to continue, but demographic scenarios indicate that the population of China will peak and subsequently decline. As a result, it is unsure how urban areas will develop after peak population. In this study we further develop the CLUMondo land system model to simulate land system changes in China until 2050. Our application represents a range of settlement systems, from dense urban areas to village landscapes, differing in their built-up area as well as their population density to enable the simulation of different settlement change trajectories. Our results show that a UN high population scenario in combination with a continued decline in population density leads to an increase of built-up land of about 48%. Conversely, the UN low population scenario in combination with a constant population density could be accommodated within the current amount of built-up land in China. Due to prevailing cropland protection policies, increase in built-up land will mostly lead to a loss of natural areas, hence our scenarios highlight the opportunity space for limiting land take and saving natural areas. This study also demonstrates the need for more nuanced representation of settlement systems for the assessment of land change trajectories.

Highlights

Population change is one of the main drivers underlying the trend in urban land expansion that has been observed in recent years (Angel et al, 2011; Colsaet et al, 2018)
In comparison with Scenario 1, these results show that a low population scenario with a continued decline of population density per land system leads to a larger loss of agricultural and natural systems than a Scenario with high population project and constant population density (Fig. 4)
This process is reflected in our Scenario 4, which shows that changes in residential density lead to an increase in all types of settlement systems, despite a net decrease in total population of China of 113 Million

Summary

Introduction

Population change is one of the main drivers underlying the trend in urban land expansion that has been observed in recent years (Angel et al, 2011; Colsaet et al, 2018). The area of built-up land per person has increased, globally, which suggests that urban growth is becoming more dispersed than compact (Decoville and Schneider, 2016). This trend has for example been observed in many European countries, such as Switzerland and southern France (Chanel et al, 2014; van Vliet et al, 2019; Weilenmann et al, 2017)

Methods

Results

Discussion

Conclusion