基于SPEI的儋州市气象干旱特征分析

Analysis of the Characteristics of Meteorological Droughts in Danzhou, Hainan ProvinceBased on a Standardized Precipitation and Evapotranspiration Index

以儋州市16个乡级行政区和三都区M1176气象自动站的降水量、气温等资料为基础,采用多尺度标准化降水蒸散指数(SPEI)对2012—2020年儋州市的干旱特征进行分析,结果表明:(1)近9年来儋州市季节性干旱较明显,呈冬季-春季-秋季-夏季干旱依次递减的规律。(2)近9年来儋州市干旱覆盖范围为18%~100%,其中5年为全域性,干旱问题突出。(3)儋州市干旱时长占总时长的33.5%,总体历时偏长,各区域干旱历时性无较大差异。(4)儋州市干旱呈轻旱-中旱-重旱-特旱的递减趋势,极端干旱事件多发于西部和北部地区。(5)儋州市干旱强度总体呈现西部沿海强、东部弱的空间分布特征。

Based on the data of precipitation amount and air temperature from M1176 automatic weather stations at 16 administrative towns and the district of Sandu in Danzhou,Hainan province and with a multi⁃scale standardized precipitation and evapotranspiration index(SPEI),this work analyzes the characteristics of droughts in the city from 2012 to 2020.The results are shown as follows.(1)Droughts are significantly seasonal in Danzhou for the nine years studied,showing a progressively decreasing pattern from winter,spring,autumn and then summer.(2)For the nine years studied,18%to 100%of the city were covered by droughts,of which five years witnessed a total coverage,suggesting the seriousness of the problem.(3)Droughts persisted for 33.5%of the nine years studied,suggesting a relatively long duration.On the other hand,no major differences are found in drought duration across different parts of the city.(4)The droughts of Danzhou tend to decrease progressively in the level of severity,with most of them being at the light level,followed in turn by the moderate,severe and very severe levels,and extreme drought events are mostly re⁃corded in the western and northern parts of the city.(5)Generally,the droughts of Danzhou are more se⁃vere in the western coast than in the eastern part of the city.