基于概率分布的达州市地质灾害发生频次与降水量级的关系

The Relationship between the Frequency of Geological Disasters and the Precipitation in Dazhou based on Probability Distribution

为提高达州市地质灾害预报预警能力,基于由衰减系数计算的有效雨量,对2007-2017年达州市发生的降雨型地质灾害在不同量级雨量下的分布频次进行分析,得到不同量级降水地质灾害发生频次。结果表明:(1)在不同量级降水下地质灾害分布没有明显的规律,但是如果结合不同量级降水出现的概率分析地质灾害的分布情况,地质灾害发生频次与降水呈指数关系。(2)结合达州实际情况和地质灾害预报工作经验,定义了不同地质灾害发生频次的地质灾害气象风险等级,基于指数方程分别计算一到五级地质灾害气象风险等级对应的有效降雨量阈值。(3)经过回代检验和实际应用,雨量阈值得到了较好的验证,能够有效地指导地质灾害气象风险等级预报预警。

In order to improve the prediction and early warning ability of geological disasters in Dazhou,based on the effective rainfall calculated by the attenuation coefficient,the distribution frequency of rainfall-based geological disasters under different rainfall levels from 2007 to 2017 in Dazhou was analyzed,and the occurrence frequency of geological disasters under different precipitation is obtained The results show that:(1)There is no obvious law in the distribution of geological disasters under different levels of precipitation,but if combined with the probability of different levels of precipitation to analyze the distribution of geological disasters,the frequency of geological disasters can have an exponential relationship with precipitation.(2)Combined with the actual situation of Dazhou and the working experience of geological disaster prediction,the meteorological risk level of geological disaster of different geological disaster occurrence frequency is defined.Based on the exponential equation,the effective rainfall threshold corresponding to the meteorological risk level of geological disaster ranged from 1 to 5 level is calculated.(3)Through the back generation test and practical application,the rainfall threshold has been well verified,which can effectively guide the prediction and early warning of the meteorological risk level of geological disaster.