BackgroundUrban sprawl, as an unsustainable urban expansion, relates to direct and indirect impacts on regional climate change in urbanized regions. In this paper, the effect of urban sprawl on regional climate change has been studied using a hybrid factor analysis (FA) and analytical network process (ANP) model in Mashhad city, Iran. The methodology was divided into two main parts based on the identification of 18 urban sprawl characteristics and six climatic parameters during three time-windows of 1996, 2006, and 2016.ResultsBased on the FA, a set of chosen sprawl characteristics were reduced into five factors with a maximized total variance of the loading variables and were weighted by ANP super-matrix. Results of urban sprawl index (USI) indicated that Mashhad city had experienced rapid horizontal growth by values from 0.47 to 1.74 within 1996–2016, revealing an indication of unsustainable urban sprawl during the last decades. Based on the correlation test, a positive relation between four climatic parameters (surface temperature, surface long-wave flux, total ozone, and black carbon density) and urban sprawl was observed (R from 0.827 to 0.981). In parallel, a negative relationship between two climatic parameters (total precipitation and convective precipitation) and urban sprawl was estimated (R from − 0.691 to − 0.805).ConclusionsThe result confirmed the possible effects of urban sprawl on climatic variations. This outcome relates to a chain of urban sprawl effects on growth of construction, transportation, the assumption of fuels and subsequently high emission of greenhouse gasses such as ozone concentration, long-wave flux, and carbon density in the urban atmosphere.

中文翻译：

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在伊朗马什哈德市使用因子分析和分析网络过程的混合模型评估城市蔓延对区域气候变化的影响

背景城市蔓延作为不可持续的城市扩张，与城市化地区对区域气候变化的直接和间接影响有关。在本文中，使用混合因子分析 (FA) 和分析网络过程 (ANP) 模型在伊朗马什哈德市研究了城市扩张对区域气候变化的影响。基于识别 1996、2006 和 2016 年三个时间窗口内的 18 个城市蔓延特征和六个气候参数，该方法分为两个主要部分。 结果基于 FA，一组选定的蔓延特征被简化为五个因素加载变量的总方差最大，并由 ANP 超矩阵加权。城市蔓延指数（USI）的结果表明，马什哈德市经历了快速的横向增长，从 0.47 到 1。74 1996-2016 年，揭示了过去几十年不可持续的城市扩张迹象。基于相关性测试，观察到四个气候参数（地表温度、地表长波通量、总臭氧和黑碳密度）与城市扩张之间的正相关关系（R 从 0.827 到 0.981）。同时，估计了两个气候参数（总降水量和对流降水）与城市扩张之间的负相关关系（R 从 - 0.691 到 - 0.805）。结论结果证实了城市扩张对气候变化的可能影响。这一结果与城市扩张对建筑、交通、燃料假设以及随后的温室气体高排放（如臭氧浓度、长波通量和城市大气中的碳密度）的增长的一系列影响有关。