对干旱进行监测,有助于各级政府及时了解旱情,采取积极有效的防旱、抗旱措施,促进水利设施建设与合理布局,确保农业生产发展与粮食安全。该文采用MODIS多时相归一化植被指数与地表温度遥感影像产品,分析研究区归一化植被指数一地表温度特征空间,应用条件植被温度指数对云南省2009年9月--2010年3月干旱的时间、空间特性进行监测。监测结果表明云南省旱情随时间有所波动,但整体旱情呈发展趋势；监测期内云南省旱情分布较广,受灾面积超过70％,仅西北角小片地区受干旱影响较小,特旱区主要分布于云南省中部、东部和南部地区。应用相关研究成果对干旱监测结果进行验证,结果表明监测结果可信,能够为防灾减灾相关部门提供有力的信息支持。

Drought monitoring can help government acquire drought information in time at various levels,take positive and effective measure to drought prevention and fighting,promote the construction and rational distribution of water conservancy facilities,ensure the development of agricultural production and food security.In this paper,MODIS multi-temporal images,normalized difference vegetation index (NDVI)and land surface temperature (LST)were used to analyze NDVI-LST feature space and calculate vegetation temperature condition index (VTCI)which was used to monitor droughts in Yunnan province from September in 2009 to March in 2010.Based on the results of drought monitoring,temporal attribute and spatial distributions of droughts in the study area were briefly discussed.The results indicated that the drought occurrences had some little fluctuations,but in a developing trend; The drought widely distributed in Yunnan province,covered more than 70% of whole province,the serious drought mainly in eastern,central and southern during the monitoring period.The drought monitoring results were validated by relative study results.The monitoring results are authentic and can provide supportable information to the prevention and reduction department.