广西泥石流和滑坡地质灾害临界雨量界定方法

Study on rainfall thresholds for mud slides and landslides in Guangxi

利用2012-2016年广西泥石流和滑坡地质灾害事件及其事件前期临近自动气象站的逐小时雨量资料,采用统计的方法,确定诱发广西泥石流和滑坡灾害的临界致灾雨量,并用2017年的灾害个例及其雨量加以检验和修订。结果表明:前期降雨对广西泥石流和滑坡起主导作用,当24h雨量<152mm时,泥石流临界雨量为H1=-0.2872H24+83.55;当24h小时雨量≥152mm时,泥石流临界雨量为H1=39.9mm。广西滑坡的雨强和降雨历时曲线满足I=11.31D-0.7关系。

Based on the geologic hazard events and its corresponding hourly precipitation data from 2012 to 2016, this paper used statistical method to analyze the rainfall threshold for mud slides and sand landslides in Guangxi and used the disaster happened in 2017 to test and revise the rainfall thresholds.The results showed that antecedent rainfall played a leading role in debris flow and landslide in Guangxi.When 24 h precipitation was less than 152 mm, the rainfall threshold for mud slides H1 =-0.2872 H24 ＋83.55, otherwise the threshold H1 =39.9 mm. For landslide, the curve of rainfall last and its density follow the formula I=11.31 D-0.7.