西安市近60年降水量和气温变化趋势及突变分析

Precipitation and temperature variations of Xi′an city in the recent 60 years

利用西安市1951年-2008年的降水和气温资料,采用线性拟合、滑动t检验,有序聚类,曼肯德尔法对西安市近60年的降水量、气温等气象水文要素进行变化趋势及突变分析。首先,采用线性拟合与距平百分率研究了西安市降水量和气温的变化趋势,分析了降水日数和降水量变化特征,最后,采用有序聚类、滑动t检验和曼肯德尔对降水量和气温的突变性进行分析。趋势分析结果表明:西安市年降水量总体呈下降趋势,汛期降水占全年降水的58%,降水量的年内分布很不均匀;年平均气温、极端最低气温呈上升趋势。突变分析结果显示:西安市降水量的突变点出现1958、1975和1980年;年平均气温的突变点发生在1993年-1995年之间。

Using the data of precipitation and temperature of Xi′an city during 1851-2008,the paper analyzed the variation trends and abrupt changes of hydro-meteorological factors including precipitation and temperature using linear fitting,sliding t test,ordered clustering and Mann-Kendall methods.Firstly,the variation trends of precipitation and temperature were analyzed using linear fitting and anomaly percentage,and then the characteristics of number changes of rainy days and precipitation were analyzed.Finally,the abrupt changes of precipitation and temperature were investigated using sliding t test,ordered clustering and Mann-Kendall methods.The results showed that the precipitation decreased gradually.58% of annual precipitation was during the flood season and the precipitation distribution was uneven in the year.The annual mean temperature and extreme minimum temperature increased.The abrupt changes of the precipitation were detected in 1958,1975 and 1980,and the abrupt changes of annual average temperature were found between 1993-1995.