RDI指数在新疆5个地区干旱监测的应用

Application of RDI index in drought monitoring of five regions in Xinjiang

为加强新疆地区干旱动态监测与评估,基于阿勒泰、伊宁、乌鲁木齐、和田、哈密5个气象站近49 a的逐日降水与蒸散数据,采用计算简单、敏感性与稳定性较强的RDI指数分析了5个地区季尺度以及年尺度的干旱特征,并指出了未来新疆地区干旱评估的发展方向。结果表明:(1)5个地区在年尺度和4个季尺度上的干旱强度与频率略有差异,但干旱程度均有所下降,都存在湿润化趋势,乌鲁木齐湿润化程度最高,和田地区湿润化程度最低。(2)从季节上看,阿勒泰地区夏、秋两季湿润化程度较高,春、冬两季湿润化程度较低;伊宁和乌鲁木齐两地夏、冬两季湿润化较明显,春、秋两季湿润化程度较低;和田、哈密两地春、夏、秋三季都比冬季湿润化程度高。

Drought is a regional phenomenon in which the available water is below normal level on a certain time scale.The basic characteristics of drought are high frequency,long duration,and wide range of influence.Xinjiang is a typical arid and semi-arid region of China.Under the background of global warming,the loss of drought disasters in Xinjiang has shown a trend of expansion.In order to strengthen drought monitoring and assessment in Xinjiang,the RDI index was used to analyze the drought characteristics on seasonal scale and annual scale based on the daily precipitation and evapotranspiration data of five meteorological stations in Altay,Yining,Urumqi,Hetian and Hami Prefectures in Xinjiang.The RDI index is simple to calculate,sensitive to drought,and has strong stability.The paper analyzed the intensity,frequency,time and trend of drought in the five regions.Finally the direction of drought assessment in Xinjiang was pointed out which should be developed to forecast in order to reduce the loss of drought in Xinjiang.The results showed that the drought intensity and frequency of the five regions on the annual scale and the four seasonal scales were slightly different,but there were different degrees of humidification.Urumqi City had the highest degree of humidification and Hetian Prefecture had the lowest degree of humidification.From the seasonal point of view,the degree of humidification in the summer and autumn in Altay region was higher,but lower in spring and winter.The humidification in both Yining and Urumqi was more obvious in summer and winter but lower in spring and autumn.The humidification in spring,summer and autumn seasons in Hetian and Hami were higher than that in winter.