华北地区旱-湿转变周期的动力研究

DYNAMIC RESEARCH IN THE TRANSITION BETWEEN DROUGHT AND WETNESS OF NORTH CHINA

为研究我国华北地区降水旱涝变化的动力行为与规律,提出了利用气候层次理论,突变点数建模技术和子波分析技术结合来构建其在某一气候层次上的动力模式的方法,并应用该方法对我国华北多个站点降水资料分析和构建其年代层次变化的动力模式。最后应用所得的模式从动力学的角度揭示了我国华北地区的干湿特征。研究结果表明:我国华北地区大部分站点的降水湿润期都明显短于干旱期,干旱期要持续二十几年,而湿润期仅有几年左右。旱长湿短是华北地区降水的主要特征。

To study the dynamic behavior and rule of the transition between drought and wetness in North China, a method is put forward to set up the dynamic mode about precipitation at one specific level of climate by use of the Climate Levels theory, the wavelet analyses and the technique of setting up model according to catastrophic points. Then, this method is adopted to analyze the precipitation data of many stations in North China and set up a dynamic mode of chronological level change. In the end the mode is used to reveal the characteristics of the precipitation in this area in the sight of dynamics. The result of the research demonstrates that for most stations in this area, the phases of drought are longer than that of wetness. The former can last over twenty years while the latter can only last less than ten years. Long drought phases and short wetness phases are the main characteristics of North China.