Application of the vegetation temperature condition index to drought monitoring in Yunnan Province

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.