内蒙古武川县45年气温变化的小波分析

WAVELET ANALYSIS ON CHANGES OF AIR TEMPERATURE IN WUCHUAN COUNTY IN 45 YEARS,INNER MONGOLIA,CHINA

气温是影响土壤风蚀的重要气象因子,本研究选择内蒙古武川县1960~2005年的气温序列为研究对象,采用MHF小波函数对其进行小波分析,揭示内蒙古武川县气温变化的多时间尺度的复杂结构,分析其在不同时间尺度下的周期性和突变诊断点,为进一步研究该区域土壤风蚀成因奠定基础。研究表明：内蒙古武川县气温变化具有明显的阶段性特征,相对于20年以上时间尺度而言,武川县年均气温均表现出1984年以前偏冷期及1984年以后偏暖期的更替。在整个时间域上,以3年和22年的周期振动最强;并预测武川县气温在较大时间尺度为偏暖期。

The study focused on the air temperature time series from 1960 to 2005 in Wuchuan County, Inner Mongolia, China, which is one of important factors on soil erosion. The Mexican Hat Function （MHF） wavelet method was adopted in analyzing the temporal - frequency multi - time scale variations and jump features of air temperature, which can reveal its＇ multi - scale characteristics. Consequently, the periods and turning points of air temperature in different time - scale are revealed. Meanwhile, forecasting the trend of air temperature in the following years. It will contribute to provide scientific reference for further study on soil erosion in Wu- chuan. The results show that the air temperature contains obvious staggered features in Wuchuan County, Inner Mongolia, China. For 20 -year scale, the variation is that cold and warm varied in 1984. It also found that approximate 3 -year and 22 -year period -os- cillation is the strongest. In final the wavelet coefficients patterns exhibit a warm weather trend in the following years.