基于SPI的陕西关中地区气象干旱时空特征分析

摘要

In this paper, SPI (standardized precipitation index) was applied as the index of drought research. According to the daily meteorological data from thirty weather stations in Guanzhong Region of Shaanxi Province, SPI with time scales of year, season and month was calculated respectively, using forty- one years' meteorological data. Then spatial raster date was achieved based on the method of Kriging interpolation. The analysis of meteorological drought in Guanzhong Region indicated that annunl SPI presents decreasing trend of meteorological drought generally in the long term. In summer, SPI has an increasing trend, especially in June. However, SPI decreased remarkably in autumn and other month while SPI also appeared in decreasing tendencies of different degree. These changes of SPI showed that Guanzhong Region experienced serious annual meteorological drought with the characteristic of extremely autumn drought.The degree of meteorological drought increases gradually from southwest to northeast of the Guanzhong Region, and the eastern and north - central parts of Guanzhong Region were more susceptible to serious meteorological drought than other parts. In the year of drought, the whole region was widespread confronted with meteorological drought.%采用标准化降水指数(SPI)作为研究干旱的指标,根据陕西关中地区30个气象站41 a的气象资料,在计算年、季和月不同时间尺度SPI的基础上,采用克里金插值法获取SPI空间栅格数据,分析关中地区气象干旱的时空特征.结果表明,总体上年均SPI呈下降趋势,气象干旱程度加剧.关中地区年内呈夏季气象干旱减少、秋季增加趋势,除6月外,其他月份均呈不同程度的气象干旱加剧趋势,构成以秋季气象干旱为特别严重的年内特征.关中地区气象干旱程度由西南向东北逐渐增加,东部和中北部地区气象干旱严重;干旱年,地区内普遍发生气象干旱;正常年,局部区域仍有气象干旱发生.