Urban Land Expansion from Scratch to Urban Agglomeration in the Federal District of Brazil in the Past 60 Years.

Zhichao Li,Helen Gurgel,Peng Gong,Minmin Li,Nadine Dessay

doi:10.3390/ijerph19031032

Abstract

Empirical studies of urban expansion have increased rapidly in recent decades worldwide. Previous studies mainly focused on cities in China, the United States or African countries, with Brazilian cities receiving less attention. Moreover, such studies are rare in purpose-built cities. Taking the urban expansion from scratch (1960) to urban agglomeration (2015) in the Federal District of Brazil (FDB) as an example, this study aims to quantify the magnitude, patterns, modes, types and efficiency of urban land expansion and attempts to reveal some implications within sustainable urban expansion thinking. Annual expansion, landscape metrics, local Moran’s I index, area weighted mean expansion index, and land-use efficiency were computed. The suitability of diffusion–coalescence theory and the impact of population growth and urban development policies on urban expansion were discussed. Urban land continuously expanded and became more fragmented during 1960–2015, which mainly occurred in SSW and WSW directions. Urban land evolved in a polycentric way. Edge expansion was identified as the stable contributor, and the importance of infilling and spontaneous growth alternated. Urban expansion in this region supported the diffusion–coalescence theory. Population growth promoted urban expansion, and the creation of peripheral urban nuclei and their development were associated with the urban expansion and the changes in urban land structure. This study adds new empirical evidence of urban expansion to Brazil urbanization, and compact urbanization, population control, and efficient urban land use should be considered in the future.

Highlights

Introduction iationsWith global urbanization, more than half of the world’s population were living in cities in 2018, and this proportion is expected to reach 68% by 2050 [1]
The results indicate that urban land in the Federal District of Brazil (FDB) evolved in a polycentric way during 1960–2015
The temporal dynamics of Class area (CA), Number of patches (NP), AREA_MN, ENN_MN (Figure 3), and spatio-temporal shifts of each expansion type during 1960–2015 (Figures 7 and 8), we identified the cyclical process of diffusion and coalescence in the FDB, with the diffusion phases in 1960–1975, 1986–1997 and 2009–2015, and the coalescence phases in 1975–1986 and

Summary

Introduction

More than half of the world’s population were living in cities in 2018, and this proportion is expected to reach 68% by 2050 [1]. Urban expansion and changes in urban land structure have social, economic, ecological, and environmental impacts on urban populations and on urban sustainable development [2–5]. The Sustainable Development Goal (SDG) target 11.3 underlines the goal of enhancing sustainable urbanization in all countries by 2030. Implementing empirical studies of urban expansion permits to provide the baseline information of urban land-use change, enabling to reveal some implications for urban sustainable development [6,7]. A better understanding of urban expansion of planned cities could make a timely contribution to the literature, especially in the context of numerous new planned cities worldwide. Previous studies mainly focused on cities in China, the United States or African

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