浙江省地质灾害气象预报模型研究

ON METEOROLOGICAL FORECASTING MODELS FOR GEOLOGICAL DISASTERS IN ZHEJIANG PROVINCE

运用浙江省1950年以来的地质灾害个例,分类统计滑体性质、微地貌、原始坡高、原始坡度和滑体结构,计算灾害数量和灾害规模,并结合2008年实地考察获得的不稳定斜坡资料,通过归一化来划定浙江省地质灾害易发区,又将灾害发生时间划分成梅汛期和台汛期两大类型。对每一个类型,结合浙江省常规气象站点和中尺度雨量站资料,分别计算与地质灾害最近的气象观测点的当日雨量、前一日雨量以及连续雨日,利用拟合方法计算每日降水对灾害的贡献程度从而获得有效降雨量,根据地域气候特征计算每个气象站的各级预警临界值,从而划分地质灾害的预警级别,建立预报模型。最后对2010年梅汛期和台汛期的地质灾害进行预报检验,TS评分分别达到89.5%和75.7%。

Using the cases of the geological disaster since 1950 in Zhejiang province, the article statistically classifies the character of slopes, the minitype physiognomy, the original height of slopes, and the original gradient and configuration of slopes. It also calculates the number and size of disasters and identifies the area where geological disasters easily happen in the province by way of normalization with the data of unstable slopes in 2008, and partitions the times of disaster into periods of Meiyu and typhoons. For the two periods, the article computes recent rainfall nearest to geological disasters for the current and preceding days as well as rainfall for consecutive days based on the records from conventional and mesoscale meteorological observation stations. Using the fitting method, this paper determines the effective rainfall by calculating the contribution of daily rainfall to disasters, obtains critical prewarning values of rainfall for each of the meteorological stations by taking reference to their regional climate. In this way, levels of disaster prewarning and setup of forecast models can be accomplished. Then, a forecasting test for the Meiyu and typhoon periods in 2010 is conducted. Their TS results are 89.5% and 75.7%, respectively, suggesting good forecasts.