陕西省极端降水时空分布及暴雨洪涝致灾指标研究  

Spatial and temporal distribution of extreme precipitation and index of heavy rain flood disaster in Shaanxi province

作　　者：范倩莹 徐娟娟[1] 郑小华[1] 刘环[1] FAN Qianying;XU Juanjuan;ZHENG Xiaohua;LIU Huan(Shaanxi Meteorological Observatory,Xi'an 710014,China)

机构地区：[1]陕西省气象台,陕西西安710014

出　　处：《气象与环境学报》2025年第1期43-49,共7页Journal of Meteorology and Environment

基　　金：陕西省自然科学基础研究计划项目一般项目(青年)(2024JC-YBQN-0326);秦岭和黄土高原生态环境气象重点实验室开放研究基金课题(2022Y-5、2023Y-1)共同资助。

摘　　要：利用陕西省94个国家气象站1971—2021年的逐日降水数据,基于去趋势波动法(Detrended Fluctuation Analysis,DFA)确定陕西省极端降水阈值,采用线性倾向估计、滑动平均、功率谱分析、广义极值分布等方法分析陕西省极端降水时空分布及概率特征,并基于灾情数据建立暴雨洪涝致灾指标。结果表明:陕西省极端降水阈值呈自南向北逐渐递减的趋势,大值区主要分布在汉中及安康的南部交界处。近年来陕西各地极端降水事件频次均有一定程度的增加,陕北地区最为显著。DFA阈值略大于2 a一遇重现期阈值,一些区域由于特殊的地形影响,DFA阈值离散性较大,在黄土高原南部、关中西北部存在明显大值区,秦岭山脉南北两侧阈值跨度较大。对比陕西不同区域极端降水阈值及致灾雨量,结合地形和区域脆弱性,给出的陕南、关中、陕北地区的建议阈值分别为80、55、50 mm,可为各地区的灾害预防及强降水预警提供参考。Using the daily precipitation data from 94 national stations in Shaanxi province from 1971 to 2021,the method of Detrended Fluctuation Analysis(DFA)was used to determine the extreme precipitation threshod,and the method such as linear trend estimation,moving average,power spectrum analysis,and generalized extreme value distribution were utilized to analyze the spatial and temporal distribution,and probability characteristics of extreme precipitation.The disaster-causing index of heavy rain floods were further established based on the disaster data.The results show that the extreme precipitation thresholds in Shaanxi province generally show a decreasing trend from south to north.The high-value areas are mainly distributed at the southern border of Hanzhong and Ankang.The extreme precipitation frequencies in various parts of Shaanxi province have shown an increasing trend in recent years,being most significant in the northern region.The DFA threshold is slightly higher than that of the 2 a return period.The DFA threshold has a large dispersion due to unique terrain leffect in some areas.There are obvious high-value areas in southern Loess Plateau and northwestern Guanzhong,and the threshold span crossing Qinling Mountains is large.Combined with the extreme precipitation thresholds,the disaster causing rainfall in different regions,and the terrain and regional vulnerability,the recommended thresholds for southern,central,and northern Shaanxi province are 80 mm,55 mm,and 50 mm,respectively,which can provide a reference for disaster prevention and heavy precipitation warning in various regions.

关 键 词：极端降水 去趋势波动法 重现期 致灾指标 

分 类 号：P426.6[天文地球—大气科学及气象学]