Drought monitoring using TemperatureVegetation Dryness Index(TVDI)from MODIS satellite images on a regional scale

Drought has always been one of the major hazards in semi-arid and arid regions of the world. Drought caused a series of effects on many sectors of economics , especially natural resources. During two last decades, Iran has suffered from several severe to extreme agricultural droughts which caused significant decreases in agriculture yields. In this paper, it’s tried to estimate drought and evaluation performance of the NDVI based Temperature Vegetation Dryness Index (TVDINDVI) and the LAI based Temperature Vegetation Dryness Index (TVDILAI) using vegetation and temperature MODIS products in Northern Khorasan during three years 2003 , 2008 and 2013 (as wet, Dry and normal years respectively). The results showed that TVDILAI index has performed better than TVDINDVI index. The result of linear correlation analyzed between indices and the cumulative precipitation of the currently 16 days ,early 16 days and early 1 month, 2 month, 3 month, 5 month and 7 month showed the indices, specially TVDILAI, had a close relationship with early 2 month precipitation than the others. This is due to the delayed responses of vegetation to precipitation.