Urban expansion and local land-cover change both significantly contribute to urban warming, but their relative importance changes over time
Urban expansion and local land-cover change both significantly contribute to urban warming, but their relative importance changes over time
复制标题
城市扩张和当地土地覆盖变化都会对城市变暖产生显着影响，但它们的相对重要性随着时间的推移而变化
DOI：
10.1007/s10980-016-0484-5
复制
发表时间：
2017-04-01
影响因子：
5.2
通讯作者：
Yu, Wenjuan
中科院分区：
文献类型：
--
作者：
Hu, Xiaofang;Zhou, Weiqi;Yu, Wenjuan
城市热岛效应不仅影响地球化学循环，而且影响人类社会。以前的研究表明，城市扩张和当地土地覆盖的变化可能会导致城市的温度高于邻近的农村。城市和地方尺度因子对城市变暖的共同影响及其相对重要性的研究很少。ObjectivesWe研究了1983 - 2011年北京城市化对城市变暖的总体影响，调查了城市规模和地方开发土地比例如何共同影响空气温度，并量化其相对重要性随着时间的推移。MethodsWe比较了城市和参考站之间的温度趋势，并进行线性回归，以评估城市和地方尺度的影响，结果城市化对气温变化趋势有显著影响，尤其是在夏季。城市化引起的年平均气温变化趋势为0.3-0.4 °C，夏季为0.4-0.6 °C。城市规模的增加和当地开发土地的比例都有助于城市变暖，但它们的相对重要性随时间和季节变化而变化。当城市规模较小时，局地尺度因子对气温起着重要作用，而在夏季局地尺度绿地较多时，局地尺度因子对气温的影响更为重要。但是，如果当地绿地较少，城市尺度因素可能会导致夏季更强的热应力。当城市规模很大时，城市尺度因子成为影响气温的唯一显著因子。结论当城市规模相对较小时，优化当地土地覆盖的组成或配置可以有效缓解城市热岛效应。然而，当城市已经很大时，更有效的方法是控制额外的蔓延。
ContextThe urban heat island (UHI) affects both biogeochemical cycles and human society. Previous studies of UHI indicate urban expansion and local land-cover change can lead to higher temperatures in cities compared to the adjacent countryside. Few studies have examined the joint effects of city- and local-scale factors on urban warming, and their relative importance.ObjectivesWe examined the overall impact of urbanization on urban warming from 1983 to 2011 in Beijing, investigated how city size and the proportion of local developed land jointly influenced the air temperature, and quantified their relative importance over time.MethodsWe compared temperature trends between urban and reference stations and conducted linear regressions to evaluate the city- and local-scale influences, based on meteorological data and remote sensing data.ResultsUrbanization significantly influenced trends of the air temperature, especially in summer. Trends of the mean temperature caused by urbanization was 0.3–0.4 °C decade−1yearly and 0.4–0.6 °C decade−1in summer. The increase of city size and the proportion of local developed land both contributed to urban warming, but their relative importance changed over time and varied seasonally. The local-scale factor played a vital role for the air temperature when the city size was relatively small, and were more important in summer when there was more greenspace at the local scale. However, the city-scale factor may cause stronger heat stress in summer, if there was less greenspace locally. When the city size was very large, the city-scale factor became the only significant factor affecting the air temperature.ConclusionsWhen a city is relatively small, optimizing the composition or configuration of the local land cover could effectively alleviate UHI effects. However, when the city is already large, a more effective way is to control additional sprawl.