【作者】 聂安祺；

【导师】 陈星；

【作者基本信息】 南京大学 ， 气象学， 2012， 硕士

【摘要】 京津冀城市群、长江三角洲城市群和珠江三角洲城市群是我国城市化水平最高的地区,其城市化气候效应的研究具有重大的科学和实际意义。本文利用国家基本、基准站1951-2009的逐日气候资料以及1986-2008的城市人口、GDP、用电量和建成区面积等社会经济资料,通过建立城市化指标,使用多项气候指标,采用典型城市与区域平均对比、EOF模态对应和Granger因果性检验等统计方法,分析了三个地区城市化的总体水平、发展趋势和空间分布格局,对典型城市和区域性的城市化气候效应进行了检测,并且比较了三个地区和不同方法之间的异同之处。首先,分析了人口、GDP、用电量、建成区面积的逐年序列,并利用均一化的人口资料建立了标准化城市化因子。结果表明：改革开放以来,三大城市群的城市规模不断扩大,城市化进程日趋加快,城市群发展的整体性得到加强；标准化城市化因子的EOF第一模态很好地体现了城市化水平和发展速度的空间分布格局,可以作为城市化典型模态。其次,采用典型城市与区域平均对比的方法分析了8个典型城市的城市化增温率特征。结果表明：城市化使气候整体变暖,并且夜间升温最强,近30年的城市化气候效应日益增强。并且将单站的城市化效应划分为三类：第一类称为“冷季型”,表现为冷季增暖强于暖季,夜间增暖强于白天,极端高温事件的频率减少或无明显变化；第二类称为“暖季型”,夏季增温最强,白天增暖强于夜间,极端高温事件显著增加；第三类称为“过渡季节型”,城市化效应的季节分布较为均衡,春、秋较强,极端高温事件有所增加。然后,计算37项气候指标,采用EOF模态对应法分析了区域性城市化气候效应。结果表明：三个地区中城市化效应最强的是长三角,京津冀次之,珠三角最弱；降水的城市化效应在三个地区各不相同,京津冀更加干旱,而长三角和珠三角更加湿润。其中重点比较了京津冀和长三角气温的城市化效应,共同点有两个：城市化使平均气温和最低气温显著升高,对极端气温的影响不明显；春季和秋季都有较强的城市化效应。不同点也有两个：长三角午间显著增温,京津冀无明显变化；长三角的季节变化为夏强于冬,京津冀相反。接下来,又采用Granger因果性检验的方法从另一个角度分析了区域性城市化气候效应。三个地区的次序为：京津冀的城市化效应最强,长三角次之,珠三角最不明显。京津冀和长三角有三个共同特点：气温的城市化效应强于降水；城市化使平均气温、最高气温和最低气温有所升高；城市化效应在春季和秋季最显著,在冬季最不明显。不同点体现在四个方面,分别为降水的城市化效应、最低气温与最高气温的关系、城市化对极端气温的影响,以及城市化效应在夏季的特征。最后,对比了两种方法所检测到的区域性城市化效应,虽然两种方法并不是对每一项指标都有相同的结果,但总体上还是一致的,能够比较可靠地反映出两个地区城市化气候效应的主要特征。这些主要特征为：城市化对气温平均状态有明显的影响,平均气温、最高气温和最低气温随城市化进程而升高；春季和秋季的城市化效应较强；京津冀的最低气温增温幅度大于最高气温,长三角为两者的量级相近；京津冀降水的城市化效应为减弱极端降水,并使夏季和年降水量减少；京津冀年平均及夏季、冬季的日较差有所减小。另外,还提取了若干对城市化效应最为敏感的气候指标,京津冀有14项,长三角有11项。更多还原

【Abstract】 Beijing-Tianjin-Hebei region, the Yangtze River Delta and the Pearl River Delta region are the three most developed areas in China with the highest urbanization level, so research on the effect of urbanization is of great scientific and practical significance. Based on daily climate data from national base climatological stations in the period of1951-2009and social-economic statistical data such as population, GDP, electricity consumption and urban built-up area in the period of1986-2008, with establishing urbanization index and calculating several climatic indices, the methods of comparing typical cities with regional average, corresponding EOF modes and Granger causality test were used to analyze development trend and spatial distribution pattern of urbanization, climatic effect of urbanization in the three agglomerations and typical cities was also detected and compared.Firstly, times series of population, GDP, electricity consumption and urban built-up area were analyzed, and standard urbanization index was also established using homogenized population data. The results reveal that:since Reform and Opening up, urban development of three agglomerations is continuously enlarging and accelerating, gap between different cities is also narrowing; the first EOF mode of standard urbanization index explicitly depicts spatial distribution pattern of urbanization level and speed, which can be used as urbanization mode.Secondly, urbanized warming rate of8typical cities in three regions was analyzed with the method of comparing typical cities with regional average. The results are as follows:urban temperature raises remarkably under the influence of rapid urban progress, especially during the nighttime, urbanization effect is enhancing in the last30years. Typical cities can be classified into three groups:in the first group, warming is most obvious in cold season and at night, frequency of high temperature is decreasing or shows no obvious trend; for the second group, the intensity of warming is strongest in hot season and midday, extreme high temperature events are also increasing rapidly; the last group experiences most evident warming in transition seasons which are spring and autumn, the increasing extent of high temperature is smaller than that of the second group.After37climatic indices being calculated, regional urbanization effect was detected using method of EOF decomposition and mode corresponding. The conclusions are as follows:the overall effect on climate was strongest in the Yangtze River Delta and weakest in the Pearl River Delta; urbanization effect on precipitation varies among three regions, Beijing-Tianjin-Hebei region becoming drier, and the Yangtze River Delta, the Pearl River Delta becoming more humid. Emphasis was on the characteristics of Beijing-Tianjin-Hebei region and the Yangtze River Delta. In both regions, there are significant increases in daily mean and minimum temperatures, with obvious warming in spring and autumn, while extreme temperature seems unrelated to urbanization. The difference between two regions are in two aspects: warming rate of daily maximum temperature is positive in the Yangtze River Delta, but it’s nearly zero in Beijing-Tianjin-Hebei region; urbanization effect is stronger in summer than in winter for the Yangtze River Delta, however it’s opposite for Beijing-Tianjin-Hebei region.In the next, regional urbanization effect was investigated using Granger causality test. The intensity of urbanization effect is seen as follows:Beijing-Tianjin-Hebei region> the Yangtze River Delta> the Pearl River Delta. There are three common points in Beijing-Tianjin-Hebei region and the Yangtze River Delta:urbanization effect is stronger on temperature than on precipitation; urbanization raises daily mean, maximum and minimum temperature to some extent; climatic effect is most evident in spring and autumn, and the weakest in winter. The different features are in four aspects, such as urbanization effect on precipitation, the relationship between maximum and minimum temperature, urban influence on extreme temperature and the characteristics in summer.Finally, the regional climatic effect of urbanization was compared from two alternative methods. Although they don’t have the same result for every climatic index, two methods are in good consistency as a whole, they are generally convincible to show major characteristic of urbanization effect. The same features are as follows: urbanization remarkably influences temperatures, increases in daily mean, maximum and minimum temperature under rapid urban progress; there is strong urban effect in spring and autumn; in Beijing-Tianjin-Hebei region, increasing in minimum temperature is larger than that in maximum temperature, while they are almost same in the Yangtze River Delta; in Beijing-Tianjin-Hebei region, extreme precipitation weakens, summer and annual precipitation also decreases. In Beijing-Tianjin-Hebei region, diurnal temperature range of summer, winter and the whole year decreases to a certain extent. In addition, a couple of climatic indices which are sensitive to urbanization are sorted out, the number of which is14in Beijing-Tianjin-Hebei region and11in the Yangtze River Delta.更多还原