甘肃中东部地区汛期不同强度日降水特征

Characteristics of Daily Precipitation with Different Intensities in Flood Season in the Middle and Eastern Part of Gansu Province

摘要: 利用2010~2017年甘肃省中部及河东地区1328个区域自动站5~9月的逐日降水量资料，按照Bonsal边缘分布函数方法将日降水量划分为弱、较弱、中等、较强和强5个强度等级，分析不同强度等级的降水量和降水日数的空间分布特征。结果表明：年降水日数呈现出由西南向东北减少的分布形式。年均降水量由南向北逐渐减小，同时少雨区域包含多个相对多雨区。对于不同强度等级的降水，无论是降水日数还是降水量，总体均呈现出南多北少的分布，并且随着降水等级的增加，降水日数、降水量的地区差异也逐渐显著。

Abstract: According to the Bonsal marginal distribution function, we used daily precipitation data of regional automatic stations (total 1328) in the central and east area of Gansu province and divided it into five different grades of intensity. Then we analyzed the spatial distribution characteristics of five different precipitation grades. The results show that the annual average precipitation days show a decreasing distribution from southwest to northeast. The distribution of annual average precipitation is significantly different from that of annual average precipitation days, which decreasing from southeast to northwest gradually. At the same time, there are several relatively rainy areas in the less rainy areas. For different precipitation intensity grades, regardless of the number of precipitation days or the amount of precipitation, the amount in the south is more than that in the north. And with the increase of precipitation grade, the regional differences of precipitation days and precipitation are gradually significant.