大气科学学报2025，Vol.48Issue(4)：592-602,11.DOI:10.13878/j.cnki.dqkxxb.20240708002
甘肃中部地区年最大日降水量时空变化特征及其极值重现期估算
Spatiotemporal variation of maximum daily precipitation and estimation of extreme value return periods in central Gansu Province
摘要
Abstract
Against the backdrop of global climate change,extreme weather events—such as heatwaves,droughts,strong winds,cold surges,ice and snow damage,and intense rainfall—are occurring with increasing frequency and severity.Events previously expected to occur once in several decades or even a century are now more common,leading to significant socioeconomic losses and environmental impacts.Accurately estimating the return periods of extreme precipitation events in central Gansu Province is therefore essential for improving risk reduction strategies and providing critical input for infrastructure design,regional planning,and industrial layout.This study analyzes daily and annual maximum daily precipitation data from 22 national meteorological stations across central Gansu Province during the period 1961-2023.Using EOF(empirical orthogonal function)and REOF(rotated EOF)methods,the spatial anomalies of precipitation were divided into three distinct regions(Regions Ⅰ,Ⅱ,and Ⅲ),and the spatiotemporal characteristics of annual maximum daily precipitation were examined.The Gumbel distribu-tion was then applied to estimate extreme precipitation values associated with different return periods.The results indicate that:(1)The spatial distribution of annual maximum daily precipitation shows a clear gradient,with higher values in the southwest and lower values in the northeast.Region Ⅲ is the center of maximum extremes,while Region Ⅰ exhibits the lowest values.(2)Although interannual variation is not prominent,decadal-scale trends differ between regions:Region Ⅰ shows a decreasing trend,Region Ⅱ remains relatively stable,and Region Ⅲ exhibits an increasing trend since the early 2000s.(3)Seasonal analysis reveals that extreme precipita-tion values are highest in summer,followed by autumn,and the lowest in spring.Regions Ⅰ and Ⅱ reach peak values in July,while Region Ⅲ peaks in August.Periodicity analysis shows dominant cycles of 25-30 years in Regions Ⅰ and Ⅱ and 15-20 years in Region Ⅲ,with shorter cycles(around 8 years and 5 years,respectively)observed.(4)The Gumbel distribution provides a good fit to the annual maximum daily precipitation data.The spatial patterns of 30-,50-,and 100-year return level estimates align closely with the observed annual maxima and long-term precipitation distribution,confirming the appropriateness of the Gumbel model.(5)All 22 meteorologi-cal stations passed statistical significance tests(α=0.05)for the Gumbel fit,indicating reliable estimates for ex-treme precipitation return levels.These findings are applicable for flood risk assessment and engineering hydrology in the region.关键词
最大日降水量/时空变化特征/极值重现期估算Key words
maximum daily precipitation/characteristics of temporal and spatial changes/estimation of extreme return periods引用本文复制引用
张俊红,郭俊瑞,邵清军,杨博成,郭凯忠..甘肃中部地区年最大日降水量时空变化特征及其极值重现期估算[J].大气科学学报,2025,48(4):592-602,11.基金项目
中国气象局创新发展专项(CXFZ2021Z034) （CXFZ2021Z034）
白银市气象局创新团队项目(2023005) （2023005）
