云南省楚雄市的降水特征分析

Analysis of Precipitation Characteristics in Chuxiong,Yunnan Province

根据楚雄市和郊区南华1966—2015年近50年降水资料,通过Mann-Kendall非参数趋势检验和统计分析方法对楚雄市近年来城市降水变化特征及其成因进行研究。研究表明:楚雄市年降水量整体呈略微增加的趋势;楚雄市主要受南亚季风影响,干湿季分明,年内降水量分配主要集中在雨季(5—10月);从降水天数变化来看,降水天数最多为小雨,最少为暴雨,城市的降水量和降水天数明显多于郊区,城市雨岛效应明显。降水成因既有气象因子的影响也有人文因子的影响。另外,城市发展有使城市降水量和降水日数增加的趋势。

For better analysis of the characteristics of precipitation in Chuxiong and their causation over the past few years, the rainfall data for the 50 years of 1966 to 2015 in the city and its suburban district of Nanhua were used, together with the parameters-free Mann-Kendall tendency test and a general statistic ap- proach. The result is shown as follows. The annual rainfall of Chuxiong shows a tendency of slight increas- ing. Affected mainly by monsoons from South Asia, the city has distinctively dry and wet seasons, with the annual rainfall distributed mainly in the raining season （May through October）. For the number of rainy days, light rain is the most frequent form of precipitation while heavy rain the least frequent. The rainfall and number of rainy days are much more in the urban than in the suburban areas due to significant rain island effect. The precipitation was caused by both the meteorological and anthropogenic factors. Besides, urban development tends to increase the rainfall and the number of rainy days in the urban area.