基于Logistic回归方法的林芝市山洪地质灾害预警研究

Early Warning of Mountain Flood Geological Disasters in Nyingchi Based on Logistic Regression Method

为研究西藏林芝市的山洪地质灾害的成因,针对降水、土地利用、土壤类型、坡度和植被指数等因素进行了分析。结合环境地质和降水时空分布特征,使用Logistic回归方法建立了山洪地质灾害的概率区划。依据灾害当天及前六天的日降水数据,通过Logistic回归模型建立了山洪地质灾害预警模型。研究发现:林芝市的大部分地区山洪地质灾害发生概率低于40%,概率在40%以上的区域约为1.8万km^2,约占林芝市面积的14.8%。将该模型应用于先前的山洪地质灾害统计数据进行检验,发现该预警模型对于灾害出现和不出现的预测准确率分别为87.2%和97.7%。

To study the causes of mountain flood geological disasters in Nyingchi,Tibet,the authors analyzed several major impact factors such as precipitation,land use,soil type,slope and vegetation index.Combined with the environmental geology and the spatial and temporal distribution characteristics of precipitation,Logistic regression method was used to establish the probability zoning of the disasters.Based on the daily precipitation data of the disaster day and six days before the disaster day,an early warning model of mountain flood geological disasters was obtained by the analysis of the Logistic regression.The results showed that the probability of disasters in most areas of Nyingchi was less than 40%,while the remaining area covered approximately 14.8%(18000 km^2).We applied this early warning model to test the previous statistical data of mountain flood geological disasters,and found that the prediction accuracy of the occurrence and nonoccurrence of the disasters was about 87.2%and 97.7%,respectively.