1980—2015年安徽省降水和干旱的时空变化特征

顾峰雪 张远东 李威 郭瑞 钟秀丽

摘要 基于地面气象观测的逐日降水数据，采用降水距平百分率的干旱划分等级，分析了1980—2015年安徽省降水量和气象干旱发生频率、强度的时空变化特征，结果表明：安徽省降水的年际动态和空间差异均较大，秋季降水的变异系数最大，沿淮地区是降水变异系数最大的地区，降水的年际变异随着年代际的增长而增加;在研究时段内安徽省降水呈下降趋势，但趋势不显著，江淮中部降水量下降最多;安徽省气象干旱发生的频率和强度均是秋冬季高于春夏季，秋季和冬季的平均干旱频率分别达到0.36和0.31，春、夏季分别为0.26和0.25，而干旱强度在秋季和冬季分别达到了0.90和0.75;全省平均干旱频率和干旱强度均是在1980—1989年最低，1990—1999年是干旱频率和强度最大的10年;36年平均干旱频率和干旱强度均是从南至北逐渐增大，淮北地區是干旱频率最高的区域，而干旱强度在沿淮区域最大。该研究结果可为安徽省内不同区域的水资源利用策略制定、种植结构的优化与种植模式的调整等提供理论依据。

关键词 降水量;降水距平百分率;干旱频率;干旱强度;安徽省

中图分类号 P467 文献标识码 A 文章编号 0517-6611（2021）01-0223-06

doi：10.3969/j.issn.0517-6611.2021.01.059

Abstract Based on interpolated daily meteorological data from climatological stations， we used percentage of precipitation anomalies （Pa） to analyze trend of annual precipitation， the meteorological drought frequency and severity of Anhui Province during 1980-2015. The results showed that precipitation in Anhui Province had large spatio-temporal variations. The variation coefficient of precipitation in autumn was the largest， and areas along Huaihe River had the largest coefficient of variation;precipitation decreased during 1980-2015 （low confidence）， and central part of Yangtze valley plain had the largest decrease of precipitation;the drought frequency and severity were higher in autumn and winter than that in spring and summer. The drought frequencies in autumn and winter were 0.36 and 0.31， respectively， and the drought frequency in spring and summer were 0.26 and 0.25. The drought severities in autumn and winter were 0.90 and 0.75， respectively;the drought frequency and severity were the lowest in 1980-1989， the drought frequency and severity reached the maximum in 1990-1999;the 36-year average drought frequency and severity increased from south to north. The north of Huaihe River had the largest drought frequency， and drought severity was largest in areas along Huaihe River. The study can provide basis for the optimization of regional planting structure and adjustment of planting pattern for water adaptation.

Key words Precipitation;Percentage of precipitation anomalies;Drought frequency;Drought severity;Anhui Province

在全球持续变暖的背景下，降水的变化趋势和空间分异却有很大的不确定性[1-2]。由于降水量时空分布的变化，必然对区域水资源、生态系统和农业生产以及社会经济产生重要影响[3]。不同区域降水格局的变化、未来趋势以及空间分异特征成为全球气候变化研究的重要内容之一[3-8]。……