The Vegetation Condition Index (VCI) evaluates the current vegetation health in comparison to the historical trends. The VCI relates current dekadal Normalized Difference Vegetation Index (NDVI) to its long-term minimum and maximum, normalized by the historical range of NDVI values for the same dekad. The VCI was designed to separate the weather-related component of the NDVI from the ecological element.
ππΆπΌπ=(ππ·ππΌπβππ·ππΌπππ) / (ππ·ππΌπππ₯βππ·ππΌπππ)
Together with Temperature Condition Index (TCI), Vegetation Condition Index (VCI) is used to calculate Vegetation Health Index (VHI) using formula: VHI=0.5VCI+0.5TCI
In ASIS, VCI is computed in two modality: dekadal and monthly. The dekadal/monthly VCI raster layer published in Hand in Hand Geospatial platform is further updated in the following 5 dekads (improve data precision, remove cloud pixel etc.).
Flags of raster file: 251=missing, 252=cloud, 253=snow, 254=sea, 255=background
More information, please visit FAO GIEWS Earth Observation website: https://www.fao.org/giews/earthobservation/index.jsp?lang=en
Data creation: 2014-01-01
Supplemental Information:
No data value: -9999
Citation:
Recommended citation: @ FAO - Agricultural Stress Index System (ASIS), http://www.fao.org/giews/earthobservation/, [Date accessed]
Contact points:
Resource Contact: Yanyun Li
Metadata Contact: Global Information and Early Warning System (GIEWS)
Resource constraints:
Data license policy: Creative Commons Attribution- NonCommercial-ShareAlike 3.0 IGO (CC BY-NC- SA 3.0 IGO)
Online resources:
Global Vegetation Condition Index monthly map