基于MODIS数据温度植被干旱指数干旱监测指标的等级划分

采用2000—2014年每年6—9月的黑龙江省MODIS数据，计算温度植被干旱指数（TVDI）。以过去15 a的全省40个旱作农业站点以旬为单位的土壤相对湿度为研究对象，与MODIS数据得到的TVDI相对应，根据土壤相对湿度的农业干旱等级划分标准，制定TVDI的干旱监测等级。结果显示:TVDI被分为5个等级，TVDI < 0.46为无旱，TVDI在0.46~0.57为轻旱，TVDI在0.57~0.76为中旱，TVDI在0.76~0.86为重旱，TVDI≥0.86为特旱。利用2011年实地测取土壤相对湿度数据对该等级进行验证，结果表明，验证结果准确度达到83%。证实了该等级划分结果的准确性。

Classification of Drought Grades Based on Temperature Vegetation Drought Index Using the MODIS Data

MODIS data from June to September were used to calculate temperature vegetation drought index (TVDI).We selected TVDI data of 40 dry farming sites as the research objects which is in ten days as a unit of TVDI over the past 15 years.According to the agricultural drought grade division standard of soil relative humidity,TVDI drought monitoring level was set.The results show that the TVDI can be divided into 5 levels.TVDI＜0.46 for no drought,TVDI between 0.46 to 0.57 for the light drought,TVDI between 0.57～ 0.76 for the middle drought,0.76～0.86 in the TVDI for the heavy drought,TVDI≥0.86 for the special drought.Meanwhile,the agricultural drought grade division standard was verified by the soil relative humidity data of field survey in 2011.Results showed that the accuracy of the verified results reached to 83％,which demonstrates that the classification of TVDI is suitable and practical.