四川青川县区域地质灾害气象风险预警模型研究

EARLY-WARNING MODEL OF REGIONAL GEOLOGICAL DISASTERS BASED ON METEOROLOGICAL FACTOR IN QINGCHUAN COUNTY,SICHUAN PROVINCE

降雨是诱发地质灾害的重要因素之一,中国大陆于2003年启动的区域地质灾害气象预警取得了较好成效,目前区域地质灾害气象预警业务逐步从地质灾害发生的"危险性"预警向"风险性"预警转变,开展区域地质灾害气象风险预警模型研究具有重要意义。本文总结提出了区域地质灾害气象风险预警概化模型及其计算方法,以四川省青川县为例,构建了青川县区域地质灾害气象风险预警模型,并以典型实例进行了预警效果校验。(1)区域地质灾害风险预警指数(R)可以概化为地质灾害潜势度(Q)、降雨诱发因子(T)和地质灾害承灾体脆弱性指标(V)三者的乘积,并分别给出了三者的计算公式。(2)构建了青川县区域地质灾害气象风险预警模型,给出了根据预警指数值划分区域地质灾害气象风险预警等级的依据,提出当Q、T、V中两项达到高等级(0. 8),一项达到较高等级(0. 6)时,为红色预警;当Q、T、V中两项达到较高等级(0. 6),一项达到中等级(0. 3)时,为橙色预警;当Q、T、V中一项达到较高等级(0. 6),两项达到中等级(0. 3)时,为黄色预警。(3)以2018年6月26日为典型实例,模拟了四川青川县区域地质灾害气象风险预警实况并进行校验,结果显示94. 1%的灾害点位于预警区范围内。

Rainfall is one of the important factors that induce geo-hazards. The early warning of regional geo-hazards based on the meteorological factor started in 2003,had achieved good results. The current early warning of regional geo-hazards are step by step from the “danger warning” to “risk warning”. Early-warning model study of regional geo-hazards risk based on the meteorological factor is of great significance. This paper put forward the general model of early warning for regional geo-hazards risk based on the meteorological factor, and took a case study of Qingchuan County, Sichuan Province. Finally, the effect of the early warning was verified with a typical example.(1)The regional geo-hazards risk warning index( R )could be generalized as the product of geo-hazards potentiality parameter( Q ),rainfall trigger factor( T ) and vulnerability index( V ). The calculation formulas of the three index( Q,T,V )were given respectively.(2)The early warning model of regional geo-hazards risk based on meteorological factor was established in Qingchuan County. According to the early warning index of regional geo-hazards, the principle dividing warning level was given. When two items of Q,T and V reached a high level(0.8) and one item reached a relative high level(0.6),it was a red alert;When two items of Q,T and V reached a relative high level(0.6) and one item reached a middle level(0.3),it was a orange alert;When one item of Q,T and V reached a relatively high level(0.6), and two items reached a middle level(0.3),it was a yellow alert.(3)Taking 26 June, 2018 as a typical example, the early warning of regional geo-hazards risk based on meteorological factor was simulated. With the actual geo-hazards, the warning effect was verified. The results showed that 94.1% of the geo-hazards were located in the warning area.