Dynamics of population growth in secondary cities across southern Africa
Dynamics of population growth in secondary cities across southern Africa
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DOI：
10.1007/s10980-020-01086-6
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发表时间：
2020-08
影响因子：
5.2
通讯作者：
Andrew Zimmer;Z. Guido;Cascade Tuholske;Alexander Pakalniskis;S. Lopus;Kelly K. Caylor;T. Evans
中科院分区：
文献类型：
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作者：
Andrew Zimmer;Z. Guido;Cascade Tuholske;Alexander Pakalniskis;S. Lopus;Kelly K. Caylor;T. Evans
背景五分之二的非洲人居住在人口不到25万的城市地区。预测估计，到2050年，城市地区将新增10亿人口，导致这些较小城市地区的增长速度加快。虽然研究和开发的重点是人口众多的一线城市，但人们对较小的次要城市地区(SUA‘s)的城市增长动力知之甚少。目标我们记录了1975至2015年间南部非洲八个国家的SUA的空间分布和时间模式。我们进一步探索了SUA的增长率与气候、土地利用以及地理上与其他城市地区的接近程度之间的关系。方法我们的分析整合了空间上明确的网格人口、土地利用、基础设施和气候数据集。我们使用描述性统计、空间滞后和普通最小二乘回归模型来量化三个时期的尿酸增长率，并探索与尿酸增长模式相关的因素。结果1975-1990年间平均尿酸增长率为2.44%。我们发现，气候、距离和土地利用与城市化轨迹密切相关。此外，我们发现SUA距离大城市的距离也与城市增长显著相关。结论我们的结果突出了SUA在更广泛的非洲城市化趋势中的重要性。苏丹正在经历快速的人口变化，是经济发展进程和生计的重要组成部分。量化SuA城市化模式对于将这些小但至关重要的城市地区提升到非洲可持续城市化的更广泛背景中非常重要。
ContextTwo-fifths of Africans reside in urban areas with populations of less than 250,000. Projections estimate that by 2050 an additional one billion people will live in urban areas, causing an acceleration of growth for these smaller urban areas. While research and development have focused on primary cities with large populations, less is known about the dynamics of urban growth in smaller, “secondary” urban areas (SUA’s).ObjectivesWe document the spatial distribution and temporal patterns of SUA’s in eight countries across Southern Africa between 1975 and 2015. We further explore the relationships between SUA’s growth rates and climate, land use and geographic proximity to other urban areas.MethodsOur analysis integrates spatially explicit gridded population, land use, infrastructure and climate datasets. We use descriptive statistics and spatial lag and ordinary least squares regression models to quantify SUA growth rates across three periods and explore factors that are associated with the SUA growth patterns.ResultsAverage SUA growth rates are 2.44% between 1975 and 1990. We show that the climate, distance and land use significantly relate to urbanization trajectories. In addition, we find that the proximity of SUA to the largest cities also significantly relates to urban growth.ConclusionsOur results highlight the importance of SUA’s within broader African urbanization trends. SUA are undergoing rapid population changes and are important components of economic development processes and livelihoods. Quantifying patterns of SUA urbanization is important for elevating these small but critically important urban areas into the broader context of sustainable urbanization in Africa.