温度植被旱情指数在吉林省干旱监测中的应用

遥感技术在干旱监测中具有其他技术不可替代的优势。利用2005年8~9月的MODIS产品,获取逐日地表温度数据和逐日植被指数数据,建立了LST|NDVI特征空间,根据此特征空间建模,计算得出温度植被干旱指数作为表征干旱的监测指标,并结合2005年土壤湿度数据对该指标进行定量验证。在此基础上利用ArcGIS软件分析了2005年8~9月吉林省干旱时空分布特征。结果表明：吉林省干旱总体分布趋势从东南到西北呈现出湿润到正常-轻旱-中旱-重旱的变化规律,体现出吉林省旱情的多样性和复杂性,8月19日、8月25日、9月8日正常和轻旱分布区域面积所占总区域面积比例分别为26.84%和59.53%、41.31%和41.73%、40.40%和32.83%,9月中旬轻旱和中旱分布最广,其比例分别为38.27%和36.26%；重旱和中旱分布区主要位于白城和松原市,轻旱区主要分布在长春、四平和辽源市,正常分布区集中在吉林、通化和白山市境内,湿润分布区主要分布在延边市。

Application of Temperature-Vegetation Dryness Index in Monitoring Drought in the Jilin Province

Water resource of Jilin Province were uneven distribution in time and space,which led drought had been one of the largest natural disasters in Jilin Province.Therefore,it was urgent to strengthen the monitoring,forecasting and damage assessment of drought,while Remote Sensing technology had more irreplaceable advantage than other technical means.LST-NDVI feature space was established with Land Surface Temperature and Normalized Difference Vegetation Index which were from MODIS products.According to the feature space,models were built to calculate the temperature vegetation drought index,which was a drought situation indicator.This paper studied the drought space-time distribution characteristics of Jilin Province in 2005 through temperature vegetation drought index,which was validated by soil moisture.The results showed there was significant correlation between temperature vegetation drought index and soil moisture,and this method could be used as a reference in the drought monitoring of Jilin Province.We found that drought distribution of Jilin trend from southeast to northwest,presenting from moist to normal,light drought,drought and severe drought; On August 19,August 25,and September 8 of 2005,ratios of the normal and light drought distribution area to the total area were 26.84% and 59.53%,41.31% and 41.73%,40.40% and 32.83%,respectively.The distribution of drought and light drought in mid-September was the most widely,which were 38.27% and 36.26%,respectively; Severe drought and drought were mainly distributed in Baicheng and Songyuan; Light drought mainly distributed in Changchun,Siping and Liaoyuan;The normal drought concentrated in Jilin,Tonghua and Baishan,and moist mainly distributed in Yanbian.