Urban land expansion: the role of population and economic growth for 300+ cities

Richa Mahtta,Elizabeth A Wentz,Meredith Reba,Anjali Mahendra,Michail Fragkias,Karen C Seto,Burak Güneralp

doi:10.1038/s42949-022-00048-y

Abstract

Global urban populations are projected to increase by 2.5 billion over the next 30 years. Yet, there is limited understanding of how this growth will affect urban land expansion (ULE). Here, we develop a large-scale study to test explicitly the relative importance of urban population and Gross Domestic Product (GDP) growth in affecting ULE for different regions, economic development levels and governance types for 300+ cities. Our results show that population growth, more than GDP, is consistently the dominant determinant of ULE during 1970–2014. However, the effect of GDP growth on ULE increases in importance after 2000. In countries with strong governance, economic growth contributes more to ULE than population growth. We find that urban population growth and ULE are correlated but this relationship varies for countries at different developmental stages. Lastly, this study illustrates that good governance is a necessary condition for economic growth to affect ULE.

Highlights

Urbanization is fundamentally a process including both urban population growth and urban land change[1]
What explains the physical expansion of cities? Does having more people in urban areas lead to the expansion of urban land? Or does economic activity drive urban land use change? With forecasts of global urban population growth of 2.5 billion between 2018 and 2050, there is an urgent need to understand how this massive demographic shift may affect the expansion of urban land areas
Our study is different from past studies because we focus only on population and economic growth as the dominant drivers of urban land expansion (ULE) and examine how geographic region, stage of economic development, and quality of national governance affect the relative importance of these factors

Summary

INTRODUCTION

Urbanization is fundamentally a process including both urban population growth and urban land change[1]. Because the majority of the existing literature tends to focus on single case studies, and testing various potential exploratory variables driving ULE, there is very little understanding of how the level of economic development and demographic change affect ULE across different contexts, or in particular regions, countries, or cities. A city’s ULE rate has increased from 0.16 to 0.23 with one unit increase in population between pre-2000 to post-

RESULTS

DISCUSSION

CODE AVAILABILITY