北京地区自动站降水特征的聚类分析

AWS Precipitation Characteristics Based on K-Means Clustering Method in Beijing Area

利用2007—2010年北京123个自动气象站逐时降水观测资料,采用聚类分析方法,对北京的主城区、西部和北部区、东北区、东南区共分为4个区域的逐时降水时空分布特征进行了分析。结果表明:通过与实际地形和下垫面类型比较,自动站分类较为合理,避免了在区域划分方面的主观因素影响。主城区降水集中时段最为突出,集中出现在7月逐日20—00时,且降水强度最强,降水量较大,降水小时数不多。西部和北部区降水集中出现在6月逐日18—20时、7月逐日23时至次日03时,降水小时数最多,降水强度不大,降水量不大。东北区降水主要集中出现在7月逐日00—08时和17—23时,降水小时数较多,降水强度不大,降水量最大;东南区降水主要集中出现在7月的逐日02—04时,降水小时数少,降水强度较大,降水量较大。

By using K-means clustering method,hourly precipitation data from 123 automatic weather sta-tions (AWS)in Beijing Area during the period of 2007-2010,the precipitation distribution characteristics of the four areas including North and West area,Northeast area stations,Urban area stations and South-east area stations are analyzed.Compared with the actual topography and underlying surface types,the classification of automatic stations is more reasonable and can avoid the influence of subj ective factors in the regional classification.In Urban areas the precipitation concentration period is the most prominent, mainly in 20:00-00:00 BT daily July with strongest intensity,greater amount and in fewer hours.In the North and West area precipitation mainly appears in 18:00-20:00 BT daily June and 23:00-03:00 BT the next day daily July,with weaker intensity,and less amount and in more hours.In the Northeast area pre-cipitation mainly appears in 00:00-08:00 BT and 17:00-23:00 BT daily July,with the weakest rainfall intensity and the maximum precipitation amount and in more precipitation hours.In the Southeast area precipitation mainly appears in 02:00-04:00 BT daily July,with stronger intensity and greater amount,and in fewer hours.