台风“鲇鱼”强降水引发的地质灾害气象风险预警检验与分析

Verification and analysis of meteorological early warning of geological hazards during precipitation of Typhoon "MEGI"

2016年9月28日,台风“鲇鱼”造成的强降水在浙江和福建引发多起地质灾害,造成严重人员伤亡和财产损失。利用中国气象局气象灾害管理系统和中国地质环境监测院提供的灾情资料,结合加密自动站降水观测、多源降水预报、承灾体脆弱性和暴露度等信息分析致灾因子,定量检验中央气象台地质灾害气象风险模型性能,并对格点化定量降水预报产品使用进行了讨论。结果表明:降水是本次地质灾害过程的主要致灾因子;国家级地质灾害气象风险预警产品命中率和漏报率分别为67.8%和11.1%,各项定量检验指标均优于客观模型;第二代中央气象台地质灾害气象风险模型预报命中率高于第一代模型的原因可能是其引入了高分辨率的地理学信息,第一代模型在地质灾害易发区出现特大暴雨时,有直接预报最高风险等级的缺陷,此外两代模型均存在明显空报现象;格点化定量降水预报产品能定点、定量地预报降水,相比主观降水等级落区预报更适用于地质灾害气象风险预警业务,但使用时需要注意其可能在一些地形复杂区域存在局限性。本检验结果只是针对一次台风过程得出的,还需要更多的个例分析和统计检验以确定结论是否具有普遍规律。

"MEGI",the No.17 typhoon in 2016,generated many geological hazards(geo-hazards)in Fujian and Zhejiang Provinces and caused many death and property loss on 28th September.Based on hazard data from hazard management system of China Meteorological Administration and China Institute of Geo-Environmental Monitoring,and combined the precipitation observation,precipitation forecast from many sources,hazard-affected body fragility and exposure degree,this study made analysis to the geo-hazards generation factor,verified in quantitative to the warning effect of Geo-hazards model of National Meteorological Centre(NMC),and summarized the experience of gridded quantitative precipitation forecast using.Result shows that,Precipitation was the main cause of geo-hazards.national meteorological early warning of geological Hazards'hit and miss rate were 67.8%and 11.1%,which were better than model.The hit rate of second generation model better than the first might because of using geological information in high resolution,the first and second generation model had the problem of false alarm,the first generation of geo-hazards model of NMC had the problem of forecasting highest level risk at places with high risk of geological Hazard in condition of had or will have extraordinary rainstorm.Gridded quantitative precipitation forecast had the advantage of higher resolution and could make quantitative precipitation forecasting in given place than rank precipitation forecast made by forecaster,which were more suitable for meteorological early warning of geo-hazards,but attentions should be paid to the defect of forecasting ability in places such as terrain complex area.Conclusions were based on typhoon"MEGI",more analysis and verification are needed to testify whether the result was regularity in future.