【摘要】 利用谱分析方法研究了常德市10年降水酸度月均值的周期变化.将加窗周期图谱估计与三角函数拟合相结合,分别确定各主要周期长度并以所得数据对数据序列进行三角函数叠加拟合.结果表明,降水酸度月均值具有12、7、4、18、3、6个月的周期变化,以7个主要周期分量可以很好地模拟降水酸度月均值的变化更多还原

【Abstract】 The periodic change of monthly rain acidity in the past ten years in Changde City was analysed by the method of spectral analysis.The length of each period was determined by way of combining periodogram spectral estimation and triangular function fitting.The triangular function model was fitted with the main periods superposed.The result shows that there are 6 periodic changes in the time series of monthly rain acidity.The length of each period is respectively 12,7,4,18,3,6 months.The series can be fitted as the function of the main periods.更多还原