城市化对云南高原楚雄市近年来城市热岛效应影响研究

Influence research of urbanization on urban heat island effect in Chuxiong city on Yunnan Plateau in recent years

气象学界对北京、上海、兰州、乌鲁木齐、昆明等大城市的城市热岛效应进行了大量研究,但用于城市和郊区对比的气象站比较少,对云南高原中小城市的城市热岛效应研究较少。近年来随着我国经济的发展,一些位于生态脆弱区的边远地区城市化发展对区域气候和环境带来的影响备受关注。楚雄市地处云南高原中部,主要位于南亚季风气候区,近年来气象灾害频繁,是世界上生态和气候脆弱区之一,该地区城市化发展对区域气候的影响引起人们的广泛关注。2010年以来在云南高原楚雄市城郊建立了多个加密气象站,很大程度上提高了研究数据的可靠性,基于楚雄市气象局近5 a来城市和郊区10个气象观测站的实测数据和社会统计数据,将气象站点资料分成城市气象站与郊区气象站资料并进行对比分析,利用Excel和surfer软件制作图表对楚雄市热岛强度的时空分布特征及影响机理进行了研究,并提出了减轻热岛效应的对策。结果表明:时间分布上,近年来城市热岛强度呈先下降后上升趋势,热岛强度最大是在2010年(1.8℃),最小是在2013年(1.2℃);3月份热岛强度最强(2.6℃),8月份最弱(0.9℃);春季热岛强度最强(2.0℃),冬季次强(1.9℃),夏季热岛强度最弱(1.0℃),秋季次弱(1.5℃);日变化热岛强度最大是在夜间02时(2.0℃),最弱是在在白天14时(-0.3℃)。在空间分布上,城市热岛中心位于城市中心,城市热岛强度分布呈城区中心向外递减的趋势,这与楚雄市地形及土地利用现状有很强的对应关系。影响楚雄市热岛强度最大的自然因素是风速,其次为蒸发量、云量和降水量;影响楚雄市热岛强度最大的人为因素是能源消耗量,其次为建成区面积和烟粉尘排放量。研究结论将对认识云南高原城市发展的区域气候效应机理,及其城市防灾减灾和可持续发展具有重要的科学意义。

Although many studies have been done on urban heat island effect in many metropolis such as Beijing,Shanghai,Lanzhou,Urumqi,and Kunming City,the weather stations which are used to make comparison between cities and suburbs are few,the urban heat island effect research is also few in medium-sized cities of Yunnan plateau. In recent years,with the development of Chinese economy,the topic＂urban development impact on regional climate and environment＂gets lots of attentions in some remote and ecologically fragile areas. Located in the central of Yunnan Plateau and belong to South Asian monsoon climate,Chuxiong City suffered frequently the meteorological disasters recently,making it rather important to study the influence of urbanization on regional climate in Chuxiong City. Since more weather stations were established in Chuxiong City and its suburb after 2010,the reliability of data was improved. Based on the measured data and statistical data from 10 weather stations of Chuxiong City Bureau of Meteorology in recent five years,this paper analyzed the spatial and temporal distribution characteristics and influencing mechanism of the intensity of heat island in Chuxiong City. Results show that at time scale,the intensity of heat island in Chuxiong increased first and then soon decreased in recent years;the maximum intensity of heat island appeared in 2010（1.8 ℃）,and the minimum intensity of heat island appeared in 2013（1.2 ℃）;during a year,the intensity of heat island showed the trend Spring（2.0）〉Winter（1.9）〉 Autumn（1.5 ℃）〉Summer（1.0 ℃）,with the maximum intensity of heat island appeared in March（2.6 ℃）,and the minimum intensity of heat island appeared in August（0.9 ℃）;in a day,the maximum intensity of heat island appeared in 02 a.m.（2.0 ℃）,and the minimum intensity of heat island appeared in 14 p.m.（-0.3 ℃）. At spatial scale,the center of urban heat island intensity was also the center of Chuxiong City,and presented outward diminishing trend,which showed high correlations with topography and land-use situation of Chuxiong City. The most important natural factor that influences the intensity of heat island was wind speed;evaporation,cloud cover and precipitation were the secondary important natural factors;the most important human factor that influences the intensity of heat island was energy consumption;built-up urban area and smokedust emissions were the secondary important human factors. The conclusions will make important scientific contributions to the study of regional climate effect on city development in Yunnan plateau,and also the urban disaster prevention and reduction and sustainable development.