| Thunders not only threaten the safety of human kinds, but also damage constructions and the foundational systems of electricity, electronic communication and aerospace, etc.. The financial cost of the disaster of thunder and lightning also increases with the growing dependence of the human society on modern industries. Therefore, the importance of the researches on the thunder and lightning changes and locations, also further appropriate forecasting can be seen in the areas of the disaster prevention and mitigation, and enlarging the meteorological services.The meteorological characteristics of thunderstorm activities are one of the important aspects of the thunderstorm research, which reflect the long-term statistic results of the temporal and spatial variations of the thunderstorm activities. The longer history of the statistical data is, the more accurate meteorology representativeness describes the thunderstorm activities. Generally speaking,30 years (at least) of observation data is required to define a typical thunderstorm. In this dissertation, the characteristics of the temporal and spatial variation of the thunderstorm activities in Shanghai is analyzed with EOF methods. Data collection contained daily records of the thunderstorms in Shanghai in 39 years (1971-2009), and the data from the lightning position indicator. Cycle analysis of Morlet wavelet is also used. EOF has advantages in the reflection of the characteristics of the temporal and spatial variation of the meteorological fields. It can divide the meteorological elements fields into non-temporally related spatial function part (eigenvector), and non-spatially related temporal function part which is decided by the main characteristic of the meteorological elements fields. Furthermore, the convergence rate of EOF is fast, thus it only requires the first few large eigenvectors to fully define the main characteristics of the expanding elements fields:Wavelet theory had already been widely used in areas of signal processing technology though it is newly developed in recent years.The results of this study are:the consistency of thunderstorm activities in all area in Shanghai, and under this circumstance, a reverse is known by comparing the thunderstorm activities in the north-west to south-east area and in the south-west area and north-east area; a certain cycle exists in the daily changes of thunderstorms. According to the detection information (data from 2009 to 2010) of the Lightning Protection Center of Shanghai, the daily-observation of thunderstorms and the results from lightning position indicator is compared, and consistency between both is confirmed. Feasible methods of lightning forecast are discussed, and the forecast of all lightning activities from 14:00 to 17:00 in 14th July, 2010 is simulated by using the observation data of the monitoring net of the Lightning Protection Center of Shanghai. This article includes six chapters. The first chapter introduced the damage causes of thunder and lightning, researches from both the domestic and abroad, the purpose of this study and prevention approaches. Chapter two introduced the theories and equipments of thunder detecting. Chapter three introduced the current researches of thunder and lightning detection in Shanghai area. Chapter four analyzed the spatial and temporal characteristics of the daily-data of the thunderstorms from 11 meteorological stations of Shanghai from 1971 to 2009, using the methods of EOF and wavelet analysis. At the mean time, related statistical analysis of information from the lightning position indicator of the Lightning Protection Center of Shanghai is also done in this chapter. Chapter five focused on the short-term forecast and alert methods by analyzing the thunder and lightning detecting information from the Lightning Protection Center of Shanghai, and proved the hypothesis by the existed data, which need further examination in the real world. Chapter six provided a conclusion and research advices for later works.
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