基于最优概率分布函数的成都市近63a干旱特征分析  

Analysis of drought characteristics in Chengdu over the past 63 years based on the optimal probability distribution function

作　　者：任至涵 倪长健[1] 石荞语 陈宁 REN Zhihan;NI Changjian;SHI Qiaoyu;CHEN Ning(School of Atmospheric Sciences,Chengdu University of Information Technology,Chengdu 610225,China;Qionglai Meteorological Bureau of Sichuan Province,Qionglai 611530,Sichuan,China;Sichuan Provincial Climate Center,Chengdu 610031,China;Meishan Meteorological Bureau of Sichuan Province,Meishan 620060,Sichuan,China)

机构地区：[1]成都信息工程大学大气科学学院,四川成都610225 [2]四川省邛崃市气象局,四川邛崃611530 [3]四川省气候中心,四川成都610031 [4]四川省眉山市气象局,四川眉山620060

出　　处：《干旱气象》2024年第6期844-853,共10页Journal of Arid Meteorology

基　　金：国家重点研发计划(2023YFC3709301);四川省科技教育联合基金项目(2024NSFSC1983)共同资助。

摘　　要：研究成都市不同尺度干旱时空分布特征对该地区农业、经济发展及干旱防灾减灾等具有重要意义。利用成都市14个国家气象站1960—2022年逐月降水数据,选择标准降水指数(Standardized Precipitation Index,SPI),首先通过对SciPy库概率分布函数的优选,确定成都市14个国家气象站年及季降水序列的最优概率分布函数;其次,基于最优概率分布函数分别计算得到年尺度和季节尺度的SPI(分别简称“SPI_(12)、SPI_(3)”);最后,基于SPI_(12)和SPI_(3)分析成都市年、季尺度干旱的时空分布特征。结果表明:不同尺度降水序列最优分布函数均通过K-S检验(显著性水平α=0.05),最优概率分布函数均能很好地表征成都市不同尺度降水序列的分布特征。成都市年及四季干旱站次比、干旱强度均呈弱增强趋势。年及四季干旱频率为25.40%~36.51%,不同尺度干旱频率的空间分布存在较大差异,相比秋旱和冬旱,春旱和夏旱发生频率略高。成都市14个区(市、县)不同等级年旱、春旱、夏旱、秋旱和冬旱的空间分布具有较大差异,但均以轻旱和中旱发生频率较高。Studying the spatial and temporal distribution characteristics of drought at different scales in Chengdu is of great signifi⁃cance to agriculture,economic development and drought disaster prevention and mitigation in this region.Using the monthly precipita⁃tion data of 14 national meteorological stations in Chengdu from 1960 to 2022,combining the standardized precipitation index(SPI),the optimal probability distributions of the series of annual and seasonal precipitation data of 14 national meteorological stations in Chengdu were determined based on the optimization of probability distributions belonging to SciPy package firstly.Secondly,based on the optimal probability distribution function,the annual scale SPI(SPI_(12))and the seasonal scale SPI(SPI_(3))were calculated,respec⁃tively.Finally,based on SPI_(12) and SPI_(3),the spatio-temporal distribution characteristics of drought at the annual and seasonal scales in Chengdu were analyzed.The results show that the optimal probability distributions of precipitation series at different scales past the KS test at significant level ofα=0.05,representing the distribution characteristics of precipitation series at different scales in Chengdu.The annual and seasonal drought station ratio,as well as the drought intensity in Chengdu,show a slight increasing trend.The drought frequency at annual and seasonal scales in Chengdu range from 25.40%to 36.51%.There are significant differences in the spatial dis⁃tribution of drought frequencies at different scales,with spring and summer droughts occurring slightly more frequently compared to au⁃tumn and winter droughts.The spatial distribution of different grades of annual drought,spring drought,summer drought,autumn drought,and winter drought in 14 districts and counties of Chengdu show considerable variability,but light and moderate droughts oc⁃cur with the higher frequency in all cases.

关 键 词：干旱 时空分布特征 标准降水指数 成都市 

分 类 号：P429[天文地球—大气科学及气象学]