This index is a weekly depiction of vegetation stress across the contiguous United States.
VegDRI maps are produced weekly and provide regional to sub-county scale information about drought's effects on vegetation.
In 2006, VegDRI covered seven states in the Northern Great Plains (CO, KS, MT, NE, ND, SD, and WY). It has undergone multiple expansions:
- 2007 - NM, OK, MO, and TX
- 2008 - WA, ID, OR, UT, CA, AZ, and NV
- 2009 - Eastern U.S.
The VegDRI calculations integrate satellite-based observations of vegetation conditions, climate data, and other biophysical information such as land cover/land use type, soil characteristics, and ecological setting. The VegDRI maps that are produced deliver continuous geographic coverage over large areas, and have inherently finer spatial detail (1-km2 resolution) than other commonly available drought indicators, such as the U.S. Drought Monitor.