地形降水具有区域性、季节性和复杂性的特点，在全球水循环及能量收支中扮演着重要角色。已有研究从天气学和动力学角度，揭示了华南丘陵地形对前汛期降水过程有着重要作用，但迄今对该类降水过程的微物理参数特征的认识还十分有限。本项目将使用全球降水测量卫星（GPM）双频测雨雷达（DPR）提供的回波廓线、地表降水率、粒子谱分布廓线等降水信息、ERA-5再分析数据及NGDC高分辨率地形数据。（1）利用降水系统识别及多源数据匹配方法，构建一套包含地形高度、大气参量、降水结构及微物理参数的华南前汛期降水系统融合数据集。（2）基于此数据集，研究揭示华南前汛期丘陵地形对于降水系统微物理参数特征的影响。（3）并结合环流场背景，探索华南前汛期各类天气尺度环流与丘陵地形相互作用下的降水分布及结构特征。本项目研究内容的完成，将提升我们对丘陵区域云和降水的物理学认知，并为模式研究提供检验数据。

Orographic precipitation has regional, seasonal, and complex characteristics, and plays an important role in the global water cycle and energy budget. From the perspective of meteorology and dynamics, previous studies have revealed that the hilly terrain over Southern China exerts an important impact on the precipitation process during the pre-flood season. However, further researches on the characteristics of microphysical parameters of these orographic precipitations are still lack. In this project, we will use the precipitation information including reflectivity profile, near-surface rain rate, and droplet size distribution profiles from Global Precipitation Measurement (GPM) Dual-frequency Precipitation Radar (DPR), ERA-5 Reanalysis data, and NGDC high-resolution terrain data. Firstly, based on the identification method of precipitating systems and the multi-source data merging method, we will establish a precipitating system dataset including terrain elevation, atmospheric parameters, and precipitation information in the pre-flood season over Southern China. Then using this dataset，the orographic effect of hills on precipitation microphysical features for precipitating systems in the pre-flood season over Southern China will be revealed. Combined with the background circulation, we will further explore the distribution and structural characteristics of precipitations under the interaction of weather-scale circulations and hilly terrain during the pre-flood season over Southern China. The results of this project would improve our physical cognition on cloud and precipitation in hilly areas and provide observational basis for model researches.