重庆市城市高温变化特征分析及对策初探

Characteristics and Countermeasures of Urban High Temperature in Chongqing City

利用1951-2011年重庆市主城区沙坪坝气象站气温资料,分析了重庆市61年的城市高温变化特征,并对其影响因素和缓解措施进行了探讨。结果表明,61年间重庆市主城区年平均气温经历了相对偏暖期、相对偏冷期和相对偏暖期三个变化阶段,其变化趋势为先降低、后升高,总趋势已转变为增暖,倾向率达0.8℃·(100a)-1;气温的变暖趋势在年平均最低气温上表现最明显,倾向率达1.4℃·(100a)-1。重庆市主城区近年来夏季平均气温的增暖趋势不明显,与年平均气温相比具有一定的滞后性。高温日数经历了低—高相间的变化过程,近年来其变化趋势逐步与全球变暖趋势步调相一致。重庆市城市高温具有高温日数多、年际变化大、持续时间长、每年首次出现时间早、高温出现时间跨度大、高温日集中等特点。重庆市城市高温由所处的地理环境和区域气候背景决定,受全球变暖大背景的影响,因城市热岛效应而加重。缓解城市高温的措施主要有:加强城市规划促进自然通风,保护利用河谷风和山谷风;重视城市绿化,增加水域面积;控制人口密度及大气污染,减少人为热释放;开展雨雾喷淋降温,调节城市小气候等。

Based on the daily temperature data measured at Shapingba weather station in Chongqing city from 1951 to 2011, the characteristics of urban high temperature in the past 61 years was analyzed. The influence factor and mitigation measure were also discussed. The results showed that in the past 61 years the annual average temperature in Chongqing city mainly experienced three stages of warmer period, colder period and warmer period. Its change tendency was first fall and then rise and the general trend was warming with a tendency of 0.8℃·（100a）-1. The warming trend of annual average minimum temperature change was the most evident, its tendency reached 1.4℃·（100a）-1. The warming trend of average temperature in summer was not evident. Combined with the change of annual average temperature, it was lagged. The change trend of the high temperature days had been ‘low-high-low-high’, and gradually consistent with global warming in recent years. The urban high temperature of Chongqing had some characteristics such as the high temperature days was many, the annual variability of the high temperature days was great, the duration of high temperature was long, the appearance time of first high temperature day in every year was early, the appearance time of high temperature days spanned a long time and the high temperature days were centralized. The urban high temperature of Chongqing was determined by the geographic environment and basic character of regional climate first, influenced by the big background of global warming, and aggravated by the urban heat island. There were some measures to reduce the influence of urban high temperature, such as strengthening the work of urban planning to increase natural ventilation, protecting and utilizing river valley breeze and mountain valley breeze, attaching importance to the city virescence, increasing water area, controlling the density of population and atmospheric pollution, reducing the release of man-made heat, developing the work of spray rain and fog to reduce temperature and then adjust microclimate of Chongqing city.