Vegetation Health Index (VHI)
Index name: Vegetation Health Index (VHI).
Ease of use: Green.
Origins: The result of work done by Kogan with NOAA in the United States.
Characteristics: One of the first attempts to monitor and identify drought-related agricultural impacts using remotely sensed data. AVHRR data in the visible, infrared and near-infrared channels are all used to identify and classify stress to vegetation due to drought.
Input parameters: AVHRR satellite data.
Applications: Used to identify and monitor droughts affecting agriculture around the world.
Strengths: Coverage over the entire globe at a high resolution.
Weaknesses: The period of record for satellite data is short.
Resources: The calculations and sample case studies are given in the literature. VHI maps can be found online at NOAA STAR – Global Vegetation Health Products webpage.
Kogan, F.N., 1990: Remote sensing of weather impacts on vegetation in non-homogeneous areas. International Journal of Remote Sensing, 11: 1405–1419. DOI: 10.1080/01431169008955102. (For more information on this paper, please contact the IDMP HelpDesk).
Kogan, F.N., 1997: Global drought watch from space. Bulletin of the American Meteorological Society, 78: 621–636. DOI: 10.1175/1520-0477(1997)078<0621:GDWFS>2.0.CO;2.
Kogan, F.N., 2001: Operational space technology for global vegetation assessments. Bulletin of the American Meteorological Society, 82(9): 1949–1964. DOI: 10.1175/1520-0477(2001)082<1949:OSTFGV>2.3.CO;2.
Currently used by: Iran.
Thank you for your question. We are only aware of the references listed on the VHI page:
However, we encourage you to do a Google search and share any results in this forum.
Are there any studies that used the vegetation health index to assess or predict crop yield and pasture availability?
Dear Lee vv
Vegetation health products are calculated from data collected during cloud-free conditions. Cloud information is collected during data collection to identify the quality of the observation. An example of such a product is the VIIRS cloud mask intermediate product (IICMO) from NASA.
I see snow and ice and missing values annotated on the map, and the cloud was not mentioned. Does the calculation of VHI including cloud?
Does an API for a system like this exist?
Dear Brian Kimathi
Thank you for your question. Here is a link to the NOAA STAR web page that has vegetation health indices: