城市化对山东省极端气温事件的影响

Effect of Urbanization on Extreme Temperature Events in Shandong Province

根据山东省气温观测资料,综合利用人口格网、土地利用和夜晚灯光数据划分了城市站和乡村站,采用基于观测资料的对比分析法研究山东省极端气温事件的城市化影响。结果表明:①除暖夜日数,暖(冷)事件在城市化的推动下会增加(减少);其中,暖指数的城市化影响贡献率分别是40.66%(高温)、19.32%(暖昼)、1.02%(暖夜),冷指数的城市化影响贡献率分别是2.31%(低温)、5.72%(冷昼)、5.55%(冷夜),可见暖事件(除暖夜日数)的城市化影响贡献率与冷事件相比更显著,且由最高气温计算得出的极端气温指数的城市化影响贡献率更大。②城市化会促使极端气温暖事件平均场的强度变大,同等强度暖事件的发生范围较之前更广,而冷事件受城市化发展的影响在强度和范围的表现却与暖事件的表现刚好相反;相同的是城市化促使极端气温冷暖事件平均场分布的空间差异性较之前均变大。③极端气温冷暖事件的突变时间会受城市化发展的影响,使其突变时间提前1～3年。④冷暖事件的持续时间会随着城市的不断发展而变化,其中由最高气温计算得出的指数受影响更大。⑤极端气温冷暖指数之间的城市化非对称性影响具有复杂的差异性。

According to the observation data of temperature in Shandong Province,using the data of population grid,land use,and night lights comprehensively,the urban and rural stations are divided.The method of comparative analysis based on the observation data is used to study the influence of urbanization on extreme temperature events in Shandong Province.The results show that:(1)Under the push of urbanization,warm events(except the warm night days)increase,while cold events decrease.The contribution rate of warm index to urbanization impact is 40.66%(high temperature),19.32%(warm day),1.02%(warm night),and the urbanization impact contribution rate of cold index is 2.31%(low temperature),5.72%(cold day),5.55%(cold night),respectively.The contribution to urbanization impact of warm events(except the warm night days)is greater than that of the cold events;in addition,the contribution of extreme temperature indices calculated by the highest temperature is greater.(2)Urbanization strengthens the average field intensity of warm extreme events.The scopes of the equalstrength warm events become more widely than before,but the intensity and scope of cold events are contrary to the performance of warm events under the influence of urbanization.Urbanization prompts the space difference of the average field distributions of extreme warm and cold events more significantly than before.(3)Urbanization may lead to the variation of mutation time,1 to 3 years earlier,of extreme temperature indexes.(4)Urbanization may affect the duration of extreme temperature events,especially the index associated with the highest temperature.(5)The asymmetrical influence of urbanization between extreme temperature indexes is of complex and diversity.