全球变暖与城市化叠加效应下的中国东部城市地区极端高温归因研究

The superimposed effect of global warming and urbanization will further increase the risk of extreme heat in urban areas and pose a serious threat to the health of urban residents. However, the current research mainly focuses on the impact of urbanization on the average state of extreme high temperature events and its changing trend, and the research on the characteristics and mechanism of interaction between extreme high temperature and urban heat island is still rare. In recent years, attribution model, which is built based on the surface energy balance equation, is often used to quantify the impact of land use change on local climate. This project intends to consider the impact of land-atmosphere feedbacks on surface temperature and further improve the existing attribution model. Taking the eastern part of China, which has rapidly developed in the past 40 years, as a research area, dynamic downscaling simulations of the impact of urbanization on regional climate are conducted. To clarify the interaction process between extreme high temperature and urban heat island and the physical mechanism of its impact on the extreme high temperature in urban areas, we quantify the contribution of different biogeophysical factors to the extreme high temperature in urban areas and identify its main controlling factors based on the improved attribution model. Furthermore, the impact of future climate change and urbanization on extreme high temperature in urban areas is also estimated in this project. These research results are of great significance for regional effective measures to mitigate and respond to extreme high temperature risks in urban areas in the future.

全球变暖与城市化的叠加效应会进一步加剧城市地区发生极端高温的风险，给城市居民健康带来严重威胁。目前城市化对极端高温的平均状况及其变化趋势的影响已有相关研究，但是对于极端高温与城市热岛之间相互作用的特征及其机理的研究尚不多见。近年来基于地表能量平衡方程建立的归因模型常被用于土地利用变化对局地气候影响的定量研究。本项目拟考虑陆表-大气相互作用对地表温度的影响，进一步完善已有的归因模型；并以近40年来城市化快速发展的中国东部地区作为研究区，对其区域气候进行动力降尺度模拟，结合改进的归因模型定量分析不同生物地球物理过程要素对城市地区极端高温的影响，阐明极端高温与城市热岛之间的相互作用过程及其对城市地区极端高温影响的物理机制，明确影响城市地区极端高温的主要控制性因素，并预估未来气候变化和城市化共同作用对城市热环境的影响。研究成果对于区域制定减缓和应对未来城市极端高温风险的有效措施具有重要意义。

全球变暖与城市热岛效应的叠加会进一步加剧城市地区极端高温的影响，给城市居民健康带来严重威胁。为进一步明确城市化过程中城市热岛与极端高温协同作用对于城市地区极端高温的影响机理，本项目针对中国地区城市化对城市地区极端高温的影响及归因开展了系列研究，并取得了以下重要成果：模拟了中国地区未来不同发展情景下土地利用的变化情况，制作并发布了相关数据集；构建了可用于定量分析不同生物地球物理过程要素对城市地区极端高温影响的归因模型；分析了城市化对不同类型（独立日间型、独立夜间型、全天型）极端高温事件的影响，揭示了极端高温与城市热岛之间相互作用对于城市热环境的影响。项目成果对于区域制定减缓和应对未来城市极端高温风险的有效措施具有重要意义。在项目期间共发表学术论文4篇，培养研究生4名。