安徽省油菜花期连阴雨灾害损失评估指标

基于安徽省油菜主产区1980-2009年44个气象台站逐日气象资料和油菜产量资料，采用数理统计方法，获得油菜历年灾损率以及花期连阴雨特征量指标即连阴雨日数、持续降水量和日照时数。按照引入因子对产量的影响最大且因子之间相关性较低的原则，筛选出连阴雨关键致灾因子并确定致灾因子临界值。最后利用K-均值聚类分析方法，建立油菜花期连阴雨灾害评估等级指标，并利用2010-2014年连阴雨灾害样本进行验证。结果表明，油菜花期的连阴雨日数和持续降水量与减产率相关性较高，且因子间相关性较低，可作为连阴雨灾害评估的关键因子；连阴雨日数致灾临界值为3d，持续降水量致灾临界值在江淮区、沿江区和皖南地区分别为20、50和70mm。利用聚类分析法构建的包括江淮、沿江和皖南地区的安徽省油菜主产区花期连阴雨灾害评估指标为：轻度灾损率5%～10%、中度10%～20%、重度20%～30%和特重≥30%，其历史回代和独立样本检验表明轻度和中度准确率较高（88%～100%），重度和特重准确率相对较低（65%～70%）。

Evaluation Index of Continuous Rain to Rape during Anthesis in Anhui Province

Based on daily meteorological data of 44 observation stations and rape yield data from each county (city) from 1980 to 2014 in Anhui province, yield losses of rape and relevant characteristic quantities of continuous rain such as continuous rainy days, continuous precipitation and sunshine duration during anthesis were calculated by use of mathematical statistics. According to the principle that the factors with the greatest impact on the yield are induced and the correlations between the factors are lowest, the disaster causing factors were chosen and their critical values were determined. In the last, the grade indices of continuous rain disaster were established by K- means clustering analysis method and the index’s veracity was verified by means of the yield losses and investigated disaster date during 2010-2014.The results showed that the main influence factors of continuous rain disaster to rape during anthesis were continuous rainy days and continuous precipitation. The threshold values of continuous rainy days were 3 days and the threshold values of continuous precipitation were 20mm, 50mm and 70mm respectively in Jianghuai, Yanjiang and South Anhui. Based on this, the grade indices of continuous rain disaster was established respectively for Jianghuai, Yanjiang and south Anhui by using K- means clustering analysis method. The damage could be defined as slight when the yield losses was between 5%-10%，moderate when the yield losses was between 10%-20%, severe when the yield losses was between 20%-30% ,extra severe when the yield losses was more than 30%.The testing results indicated that the accurate rate of slight and moderate indices were higher（88%-100%）, while the accurate rate of severe and extra severe indices were relatively low（65%-70%）.