豫西山区降水与气温的波动规律研究

根据豫西山区4个国家地面气象观测站1957—2008年的降水和气温数据,运用小波分析和统计分析相结合的方法研究了该地区降水和气温的多时间尺度波动特征。研究结果表明:①近50 a来,豫西山区的年降水量和年均气温均具有复杂的多时间尺度特征,年降水量在4 a和14 a尺度上的周期性波动特征较为明显,而年均气温在8 a和14 a尺度上的周期性波动特征较为明显;②近50 a来,豫西山区的年降水量和年均气温虽然具有明显的周期性波动,但是,使用白噪声功率谱进行显著性对比检验得出的结果表明,它们的主周期的显著性水平普遍较低,可以认为基本属于随机性波动;③近50 a来,在4~12 a的尺度上,豫西山区的年降水量和年均气温具有极显著的负相关性,而且预计未来几年该地区仍然可能延续2006年以来气温偏高降水偏少的气候特征;④小波分析和统计分析都属于经验诊断的范畴,对分析过去气候要素变化的多时间结构特征具有较好的效果。但是,由于它们不涉及因果机理,因此要想准确地预测未来的气候变化趋势,还必须对气候系统当中的复杂变化过程开展深入的机理研究。

Study on Precipitation and Temperature Change in Western Henan Mountain Area

Climate change in the past century has already had measurable impact on ecosystems. Human populations always face the risk of damage from climate change, which is now widely recognized as the major environmental problem facing the globe. Therefore, climate change needs to be factored into current development plans. Western Henan mountain area, the study area, belongs to the east-extended end of the Qinling Mountains, which is an important boundary between sub-tropical zone and warm temperate zone in China. It consequently is one of the most susceptive areas to climate change. Based on the climatic data from national meteorological observation stations, the multi-temporal characteristics of annual precipitation and annual mean air temperature during the past 50 years in western Henan mountain area were studied using Mexican Hat wavelet analysis and traditional statistical methods in this article. The results indicated that: 1) Both annual precipitation and annual mean air temperature have complex multi-temporal scale structures. Annual precipitation has obvious periodic oscillations of 4 years and 14 years, while annual mean air temperature has obvious periodic oscillations of 8 years and 14 years. 2) Although obvious periodic oscillations of annual precipitation and annual mean air temperature in western Henan mountain area existed in the past 50 years, they can be thought being caused by randomness (i.e.a Gaussian White Noise) because their statistical significance levels of wavelet analysis results against the power spectrum of a Gaussian White Noise were very low. 3) Annual precipitation and annual mean air temperature have significant converse relationship in 4-12 temporal scales during the past 50 years. That is to say, high annual precipitation is often accompanied with low annual mean air temperature in 4-12 temporal scales, and vice versa. And it is projected that it will probably continue to be high annual mean air temperature and low annual precipitation for the coming years in western Henan mountain area. 4) It should be noted that, just as statistical analysis, wavelet analysis also belongs to experience diagnosis, and is not mechanism analysis. Consequently, mechanism of complex process in climate system should be further studied to understand and explore the future trends of climate change.