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Taiwan began to carry out systematic meteorological observations in 1885. With the changes of the ages and the advancement of science and technology, the accuracy of rainfall stations has become better and better. The data from rainfall stations are not only available for public reference on the internet, but are also used by many disaster prevention studies in Taiwan. However, the settings of on-site observation instruments such as rain gauges and anemometers are easily restricted by factors such as local power, communication, and cost. Therefore, there is usually a considerable distance between stations. QPESUMS, which uses radar echoes from all radar stations in Taiwan, integrates meteorology and hydrology, and provides real-time weather monitoring information, can be used as a reference for accumulated rainfall in areas without rainfall stations. This study takes the second line of Taiwan in the northeast corner of Taiwan as the research area, and the adjacent rainfall stations are only Ruifang and Bitoujiao rainfall stations. If only the rainfall data collected by these two rainfall stations correspond to the whole area, it is slightly insufficient. Compared with the large area of one-to-one rainfall stations, the one-to-one advantage of QPESUMS in space can provide more accurate rainfall data for disaster areas. This study collected 108 disaster event records, found the center point of the disaster area, and selected 7 x 7 grid areas from the center point as the quantity control blocks. The rainfall data from 49 grids were used to analyze the impact of rainfall on the disaster occurrence. By observing the pre-disaster and post-disaster rainfall, it can be found that there is rainfall before all disaster events, and it can be judged that the cause of the disaster is related to long-term rainfall. Then, set the rainfall threshold according to the cumulative rainfall in 72 hours and the cumulative rainfall in one week, and calculate the number of rainfall events exceeding the rainfall threshold in the rainfall record year. Use the Poisson distribution to estimate the probability of another rainfall event of the same size in the future, and calculate the probability of occurrence. The probability that a disaster event may occur when the rainfall event exceeds the threshold. And multiply these two probabilities to get the probability that the rainfall event exceeds the rainfall threshold and the probability of future disaster events. The results showed that under the same rainfall threshold, the number of rainfall events exceeding the rainfall threshold in the WEST and MIDDLE regions was significantly higher than in the EAST region. However, the probability of disaster events in the EAST region was much higher than in the two regions, so the EAST region should strengthen pre-disaster prevention and control.
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