中文摘要：

基于风廓线雷达谱参数（回波强度、速度和谱宽）提出降水云分类方案,将降水分为浅对流、浅层状云、深对流、深层状云和混合型五种类型,其中浅对流和浅层状云降水属于暖雨范畴而深对流、深层状云和混合型降水属于冷雨范畴。并且利用此分类方案对2012年和2013年夏季（5-10月）北京延庆地区降水天气类型进行了分类统计。结果表明,暖雨是北京夏季降水的一个重要组成部分,占26%,其降水比例为17%;冷雨过程占74%,降水比例为83%。北京夏季以混合型降水为主占47%,其次是层状云占43%,对流性降水最少,占10%;对流性系统造成的降水最显著,其次是混合型降水,层状云对降水的贡献最小。对各种降水类型的特征归纳得到：浅层状云降水的谱参数随高度变化均不明显,总体比较平滑;浅对流性降水变化比浅层状云降水强烈,在3 km处增大明显,且降水出现次数随高度下降迅速增多;深对流性降水谱参数分布广泛,特别是谱宽,比其他类型都宽且高空存在宽谱区;深层状云降水回波呈现出统一的亮带分布,速度和谱宽在零度层附近出现强梯度区;混合型降水兼顾对流性和层状云降水特征,其回波分布跟深对流性降水类似,速度和谱宽分布跟深层状云降水分布类似。

英文摘要：

In order to analyze the characteristics of different types of precipitation in mid-latitude regions,the precipitation data have been divided into shallow convection,shallow stratiform,deep convection,deep stratiform and transition five types of precipitation based on spectral parameter（echo intensity,velocity,spectral width） of wind profile radar.The shallow convection and shallow stratiform precipitation belong to the category of warm rain,and the deep convection,deep stratiform and transition precipitation belong to the category of cold rain.In this paper,author classified and analyzed the characteristics of precipitation weather process in Beijing Yanqing during 2012 and 2013 summer（from May to October） with the above-mentioned classification scheme.The results show that,warm rain is an important part of precipitation in Beijing summer,accounted for 26%,its precipitation proportion takes 17%;cold rain accounted for 74%,the precipitation proportion takes 83%.A majority of the precipitation in Beijing summer is transition precipitation（47%）,followed by stratiform precipitation,accounted for 43%,the lest is convection precipitation,takes 10%;the greatest contribution of precipitation is convection precipitation,followed by transition precipitation,the lest is stratiform precipitation.Characteristics of all types of precipitation are summarized：the variation of spectral parameters in shallow stratiform precipitation with altitude is not obvious,the whole trend smooth relatively;the variation of shallow convection is fiercer than shallow stratiform,it increases obviously at 3 km,and the number of precipitation data is increasing rapidly with altitude descent;spectral parameters of deep convection precipitation are distributed widely,especially the spectral width,is broader than that of other types,besides,the high value area is also exist in high altitude;deep stratiform precipitation echo presenting a uniform bright band distribution,velocity and spectral width comes out a strong gradient feature nea