Urbanization and Spillover Effect for Three Megaregions in China: Evidence from DMSP/OLS Nighttime Lights

Xiaoxin Zhang,Yanning Guan,Zhuangzhuang Tian,Klaus Fraedrich,Shan Guo,Danlu Cai,Han Xiao,Chunyan Zhang

doi:10.3390/rs10121888

Abstract

Urbanization drives human social development and natural environmental changes and shows complex implications for sustainability and challenges of future development, particularly in emerging countries. While extensive studies focus on extracting urban areas more precisely, less attention has been devoted to understand megaregion evolution and its related socioeconomic processes, not by socioeconomic statistics, but by comparing remote sensing based spatiotemporal evolution and the related spillover effect. Three main megaregions (with large area, high population and total gross domestic product) in China are selected for the analysis of development changes in an urbanization (magnitude, development)-diagram, of growth pattern changes based on Gravity Center and weighted Standard Deviation Ellipses and of the megaregions’ spillover effect. Employing the spatiotemporally continuous lighted areas (DN ≥ 12) from the Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) nighttime signal (1992–2013) to the Beijing-Tianjin-Hebei (BTH), the Yangtze River Delta (YRD), and the Pearl River Delta (PRD) leads to the following results: (i) Developments in the (magnitude, development)-diagram indicate 25.97%, 45.95%, and 39.10% of the first (high urbanization, fast development) class of the BTH, YRD, and PRD megaregions are rapidly developing into highly urbanized regions. The first class may slow down in the future like the second (high urbanization, slow development) class acting from 1992 to 2013, and the third (moderate urbanization, fast development) class shows potential to become the first class in the future. (ii) The original core function zones of YRD and PRD have highly developed till 1992 and expanding out with fast development from 1992 to 2013. Contrarily, BTH indicates more fast development toward the original core function zones while spatial expansion. (iii) The gravity distance evolution of the three megaregions shows a tendency towards the geometric distance 2013. However, YRD and PRD (BTH) indicate a light intensity expansion (concentration). This may relate to a positive spillover effect of YRD and PRD upon their neighbor cities, with the strongest signal in the early 21st Century and thereafter adjusting and followed by another positive spillover.

Highlights

Urbanization is a rapid and historic transformation of human social roots on a global scale [1]
Growth pattern changes on the megaregion and city scale are characterized by two measures: the changes of Gravity Center [48] and of Standard Deviational Ellipse [49]: the concept of Gravity Center is used to identify the weighted center of megaregions and cities; and the Standard Deviational Ellipse is used to measure the spatial orientation of urban light intensity distribution and dispersion
Three largest urban areas in China are selected in terms of their administrative boundaries, which have undergone rapid urbanization over the recent decades: the BeijingTianjin-Hebei (BTH with cities), the Yangtze River Delta (YRD with cities) and the Pearl River Delta (PRD with 10 cities)

Summary

Introduction

Urbanization is a rapid and historic transformation of human social roots on a global scale [1]. More than one half of the world population lives in urban areas, and virtually all countries of the world are becoming increasingly urbanized [2] This global phenomenon has very different expressions across regions and development levels. A megaregion is either organically formed or planned as a result of individual, collective, and political urban agglomerations [12,13] These clustered networks of cities are physically coherent in space and functionally linked through socioeconomic processes and share several or all of the following: environmental systems and topography, infrastructure systems, economic linkages, settlement and land use patterns, culture and history [10,14]. The spatiotemporally internal and integral pattern evolutions of megaregions are discussed in terms of light intensity tendencies based development changes and land use based growth pattern changes (Section 3), followed by a concluding summary and discussion (Section 4)

Data and Methods of Analysis

Data Pre-Processing

Methods of Analyses

Results and Discussion

Spillover Effect of Megaregion on Surrounding Cities