摘要: |
本文基于铜仁市10个国家自动观测站1981-2020年近40a降水资料,计算多时间尺度标准化降水指数(SPI),确定旱涝程度,分析旱涝时空分布特征,筛选典型旱、涝年进行环流分析。结果表明:(1)铜仁市20世纪80年代后期总体偏旱,90世纪后期总体偏涝。铜仁市夏季呈现出旱涝交替变化特征。(2)铜仁市中西部、东北部干旱相对频繁,并向四周逐渐减弱;市中西部、东南部发生雨涝的频率相对较高,西北部最低。夏季的干旱和雨涝均以轻、中程度为主,特重程度情况发生很少。(3)夏季偏涝年整个欧亚中高纬均为位势高度的负异常,偏旱年欧亚中高纬的乌拉尔山和中国东北的位势高度异常中心转为正异常分布。(4)赤道中东太平洋的厄尔尼诺现象与南、北太平洋海温异常分布对铜仁夏季偏涝现象的发生发展有密切关系;赤道中东太平洋拉尼娜现象、印度洋及西太平洋的海温异常分布对铜仁夏季偏旱现象的发生发展有密切关系。 |
关键词: 标准化降水指数;时空分布;环流特征 |
DOI: |
投稿时间:2021-10-21修订日期:2022-01-05 |
基金项目:贵州省科技基金项目(黔科合基础【2018】1158) |
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Analysis of Temporal and Spatial Distribution of Summer Drought and Flood and Circulation Characteristics of Typical Drought and Flood Years in Tongren in the Past 40 Years |
Zhanglijuan |
(Tongren Meteorological Bureau of Guizhou Province) |
Abstract: |
Based on the precipitation data of 10 national automatic observation stations in Tongren from 1981 to 2020 in the past 40 years, this paper calculates the multi-time scale standardized precipitation index (SPI), determines the degree of drought and flood, analyzes the spatial and temporal distribution characteristics of drought and flood, and selects typical drought and flood years Perform circulation analysis. The results showed that: (1) Tongren City was generally droughty in the 1980s and flooded in the 1990s. Tongren City presents alternating droughts and floods in summer. (2) Droughts are relatively frequent in the central, western and northeastern parts of Tongren City, and gradually weaken to the surrounding areas; the frequency of rain and waterlogging in the central, western and southeastern parts of the city is relatively high, and the northwestern part is the lowest. The droughts and rains in the summer is mainly mild and moderate, with very few cases of extreme severity. (3) In summer, the mid-high latitudes of Europe and Asia are negative anomalies of geopotential height. In drought years, the geopotential height anomaly centers of the Ural Mountains and northeastern China turn to positive anomalies. (4) The El Ni?o phenomenon in the equatorial Central and Eastern Pacific and the anomalous distribution of SST in the South and North Pacific are closely related to the occurrence and development of Tongren summer waterlogging; the La Ni?a phenomenon in the equatorial Central and Eastern Pacific, the Indian Ocean and the Western Pacific SST anomalous distribution affect Tongren"s summer bias. The occurrence and development of drought are closely related. |
Key words: standardized precipitation index; temporal and spatial distribution; circulation characteristics |