基于相对湿润度指数的北疆气象干旱时空特征
祁嘉郁, 巴特尔·巴 克

(新疆农业大学 草业与环境科学学院, 乌鲁木齐 830052)

气象干旱; 时空特征; 相对湿润度指数; 北疆

Spatiotemporal Distribution of Drought in Northern Xinjiang Based on Relative Moisture Index
QI Jiayu, Bateer·bake

(College of Grass and Environmental Science, Xinjiang Agricultural University, Urumqi 830052, China)

meteorological drought; temporal and spatial distribution; relative moisture index; northern Xinjiang

备注

基于北疆地区26个主要气象站点1961—2016年逐日气象数据,选用国家标准相对湿润度指数(M)作为干旱指标,以年和季为时间尺度,探究北疆地区干旱强度和频率的时间变化与空间分布特征。结果表明:相对湿润度指数能够很好地表征出典型干旱年,从56 a的数据分析来看,北疆地区干旱强度总体呈减小趋势。对比各年代干旱强度,以21世纪初干旱最轻,20世纪60年代和70年代干旱最为严重,空间分布上大致呈东南高西北低的趋势; 北疆地区年轻旱频率和中旱频率呈增加趋势,年重旱频率和特旱频率呈减小趋势,历年重旱频率明显高于其他等级干旱频率,中旱频率略高于轻旱和特旱频率。季节尺度上,北疆地区春季和夏季干旱强度明显高于秋、冬季,在各季节不同等级干旱频率中,秋季轻旱频率最高,夏季中旱、重旱频率最高,春季特旱频率最高。
Based on the daily meteorological data of 26 major meteorological stations in north Xinjiang from 1961 to 2016, the national standard relative moisture index(M)was selected as the drought index, and the annual and seasonal time scales were used to explore the interannual variation and spatial distribution characteristics of drought intensity and frequency in northern Xinjiang. The results show that the relative moisture index can well characterize the typical drought year. According to the analysis on data covering 56 years, the drought intensity in north Xinjiang generally shows the decreasing trend. Compared with the drought intensity in various years, the drought was the lightest in the early 21st century, the drought was the most severe in the 1960s and 1970s, and the spatial distribution showed a trend of high in the southeast and low in the northwest. The frequencies of light drought and moderate drought in the northern Xinjiang region were increasing, while the frequencies of annual severe drought and extra drought were decreasing. The frequency of severe drought in northern Xinjiang over the years was significantly higher than that of other grades, and the frequency of moderate drought was slightly higher than that of light drought and extra drought. On the seasonal scale, the drought intensity in spring and summer in northern Xinjiang was significantly higher than that in autumn and winter. Among the drought frequencies of different grades in each season, the frequency of light drought in autumn was the highest, the frequency of moderate and severe drought in summer was the highest, and the frequency of extra drought in spring was the highest.