容县2010年6月滑坡灾害降雨阈值研究

Study on the rainfall threshold of the landslide disaster in Rong County in June 2010

大暴雨常引起群发性滑坡灾害的发生,对大暴雨引起的滑坡进行预警显得尤为重要,而确定诱发群发性滑坡的降雨阈值是预警的关键。在容县2010年6月初暴雨及其诱发的滑坡数据基础上,分析降雨和滑坡发生数量的相关性;采用降雨强度-降雨历时模型的统计分析方法,建立不同滑坡发生概率的降雨强度-降雨历时阈值线,且用ROC方法对阈值线进行检验。研究结果表明:滑坡发生数量和降雨量相关性为0.507;采用ROC方法分析得到滑坡发生概率为10%、50%、90%,阈值线的准确率分别为0.70、0.75、0.39,漏报率分别为0.05、0.23、0.93,误报率分别为0.75、0.29、0.04;综合以上指标,将50%阈值线作为研究区的阈值线,并进一步分析该线在不同日数下诱发滑坡的降雨阈值,作为容县群发性降雨型滑坡灾害预警分析。

Heavy rainstorms often cause the occurrence of mass landslides.It is especially important to provide early warning for landslides caused by heavy rainstorms,and determining the rainfall threshold for inducing mass landslides is the key to early warning.Based on the data of heavy rainfall and landslides induced in early June 2010 in Rong County,the correlation between rainfall and the number of landslides occurred was analyzed.The statistical analysis method of rainfall intensity-rainfall ephemeris model was used to establish the threshold line of rainfall intensity-rainfall ephemeris for different landslide occurrence probabilities,and the threshold line was tested by ROC method.The results show that the correlation between the number of landslide occurrence and rainfall is 0.507.The accuracy of the threshold lines with landslide occurrence probability of 10%,50%and 90%is 0.70,0.75 and 0.39,the omission rate is 0.05,0.23 and 0.93,and the false alarm rate is 0.75,0.29 and 0.04 respectively,obtained by the analysis of ROC method.The 50%threshold line is taken as the threshold line in the study area,and the rainfall threshold of this line for inducing landslides under different number of days is further analyzed as the early warning analysis of mass rainfall type landslide disasters in Rong County.