京津冀城市高温的气候特征及城市化效应

Climate characteristics and effects of urbanization of the urban high temperature of Beijing, Tianjin and Hebei, China

选取京津冀13个城市气象站点5—8月的日最高气温资料,用统计学方法分析了该区域城市高温日数的空间特征、年代际变化及跃变。采用城市站和城镇站对比方法,研究了京津冀不同区域高温的城市化效应。结论如下:(1)该区域城市高温日数的空间分布特征为,西南部存在一个高值中心,向东北方向递减,存在一个自石家庄市指向承德市的高值脊。(2)该区域城市高温日数的年代际变化为冀东北部城市1965—1998年是少高温期,1999—2010年是多高温期。冀西北部、冀中南部和京、津城市,1997—2010年是高温日最多时段,1960—1972年是次多时段,1973—1996年是最少时段。(3)冀东北部城市35℃以上高温日数,1991—1992年发生跃变,显著增加。冀中南部城市37℃以上高温日数,1996—1997年发生跃变,显著增加。北京市35℃以上高温日数,1995—1996年发生跃变,显著增加;37℃以上高温日数,1985—1986年发生跃变,显著增加。(4)冀西北部城市和冀中南部城市自1970年代开始,城市化效应逐步显现,并分别从1990年代和1980年代开始城市化效应增强。冀东北部城市和京、津两市的城市化效应近年并无增强趋势,而是小城镇的城市化效应在1990年代后期—2010年显现出来。其原因可能是城镇人口和建成面积的快速增长所致。

Using the daily maximum temperature data from May to August of 13 meteorological stations in Beijing,Tianjin and Hebei,we analyzed the temporal evolution and spatial distribution features of the urban high temperature of the above-mentioned cities.The urbanization effects of high temperature in different regions of Beijing-Tianjin-Hebei are studied by comparing the stations in the cities with those in nearby towns.The results show that：（1）The spatial distribution features of the urban high temperature of Beijing-Tianjin-Hebei show that there is a high value centre in the southwest decreasing to the northeast,composing a high value ridge from Shijiazhuang to Chengde;（2）The inter-annual variability of the urban high temperature of Beijing-Tianjin-Hebei indicate that for the cities in the northeast 1965—1998 is the period with less high temperature days,while 1999—2010 is the period with more high temperature days above 37 ℃ and 40 ℃.The other cities in Beijing-Tianjin-Hebei have the similar trends： the period of 1997 —2010 has the most high temperature days,the period of 1960—1972 comes for the second,1973—1996 is the period with the least number of high temperature days;（3） Days of high temperature above 35 ℃in the northeast region of Hebei show a significant increasing trend since 2001,it has a sudden change in 1991—1992.Days of high temperature above 35 ℃in the south region of Hebei show a increasing trend since the 21st century;days of extreme high temperature above 37 ℃in the south region of Hebei show a significant increasing trend during 1999—2010,the sudden change year is 1996—1997.Days of high temperature above 35 ℃in Beijing have an increasing trend during 1998—2010,the abrupt change occurs in 1995—1996;The ones above 37 ℃have an obvious increasing trend since the end of 1990s to the year 2010,the abrupt change year is 1985—1986.Both the days of extreme high temperature above 40 ℃in the south region of Hebei and the days above 37 ℃in Tianjin have an increasing trend since 1960;（4）Since the 1970s,effects of urbanization gradually reveal in the northwest and south region of Hebei province which gets enhanced respectively from the 1990s and 1980s.The effects of urbanization of big cities in the northeast of Hebei-Beijing-Tianjin show no increasing trends in recent years,however,the effects of urbanization in small towns gradually reveal from the late 1990s to 2010.The reason might be the rapid growth of population in small towns and the increasing of urban area.