摘要
基于安徽省81个气象站1961—2017年逐日降水数据及土壤墒情和干旱灾情资料,从诊断干旱日数年际变化、季节演变、空间分布、频率分布、典型干旱过程演变及与土壤墒情、干旱灾情的相关性等方面,研究6种时间尺度SPI在安徽省气象干旱监测效果。结果表明:不同时间尺度SPI在干旱监测中差异明显,6种时间尺度SPI对于干旱日数年际变化、不同等级干旱频率分布具有较好的监测效果,但对于干旱日数季节演变和空间差异性诊断与实况存在偏差;从典型干旱过程诊断来看,时间尺度越短,降水权重越大(例如SPI30、SPI60),SPI监测曲线对降水的响应越敏感,而SPI150、SPI180等时间尺度长的SPI对降水的响应又过于“迟钝”;从与土壤墒情的相关性来看,时间尺度短的SPI30与10 cm表层土壤墒情相关性最好,相关系数达0.91,时间尺度长的SPI180与50 cm深层土壤墒情相关性较好;在各时间尺度SPI与年降水量的负相关及与干旱灾情的正相关方面,相关系数随着时间尺度的增长均先增后减,时间尺度适中的SPI120相关性最好。总体来看,不同时间尺度SPI代表不同含义,针对不同时间尺度的气象干旱应采用不同时间尺度的SPI进行监测评估。
Based on daily precipitation data,soil moisture data and historical drought disaster data of 81 meteorological stations in Anhui Province from 1961 to 2017,this paper studies the applicability of SPI in six time scales in meteorological drought monitoring in Anhui Province,by analyzing the interannual variation,seasonal evolution,spatial distribution,and frequency distribution of the drought days,evolution of typical drought processes as well as correlations of drought days to soil moisture and to drought disaster.The results show that in drought monitoring there is significant difference in the SPI in different time scales.In interannual variation of drought days and frequency distribution of the drought at different grades,the diagnosis results got with SPI of each time scale are in accordance with the fact,but the results are not in accordance with the fact of seasonal variation and spatial difference of drought days.SPI of each time scale has a good diagnostic effect on the interannual variation of drought days and frequency distribution of the drought at different grades,but it has a poor effect on the seasonal variation and spatial diffe-rence of drought days.From the perspective of diagnosis of typical drought processes,the shorter the time scale,the higher the weight of the precipitation,thus the SPI monitoring curve is too sensitive to precipitation,such as SPI30 and SPI60.However,the response of SPI150 and SPI180 of long-time scale to precipitation is too insensitive.From the perspective of correlation with soil moisture,the short-time scale SPI30 has close correlation with surface soil moisture of 10 cm depth and the correlation coefficient is 0.91,while the long-time scale SPI180 has close correlation with deep soil moisture of 50 cm depth.In the aspects of negative correlation between SPI in different time scales and annual precipitation and the positive correlation between them and drought disaster,correlation coefficients first increase and then decrease with the time scale prolonging,and the moderate-time scale SPI120 has the closest correlation to them.Overall,SPI in different time scales represent different meanings,and the drought in different time scales should be monitored and evaluated by SPI in different time scales.
作者
谢五三
唐为安
宋阿伟
XIE Wusan;TANG Wei’an;SONG Awei(Anhui Climate Centre,Hefei 230031;Anhui Key Laboratory of Atmospheric Science and Satellite Remote Sensing,Hefei 230031)
出处
《气象》
CSCD
北大核心
2019年第11期1560-1568,共9页
Meteorological Monthly
基金
中国气象局气候变化专项(CCSF201714)
淮河流域气象开放研究基金(HRM201607)
安徽省自然科学基金面上项目(1908085MD109)
安徽省重点研究和开发计划(201904a07020099)
安徽省气象局科研项目(KM201903)共同资助
关键词
标准化降水指数
多时间尺度
干旱监测
安徽省
standardized precipitation index
multiple time scale
drought monitoring
Anhui Province
