Vegetation Cover Index

“Kogan proposed a Vegetation Condition Index (VCI) based on the relative Normalized Difference Vegetation Index (NDVI) change with respect to minimum historical NDVI value. The VCI therefore compares the current Vegetation Index (VI) such as NDVI or Enhanced Vegetation Index (EVI) to the values observed in the same period in previous years within a specific pixel.

Image displays the formula to calculate the VCI
where VCIijk is the VCI value for the pixel i during week/month/DOY j for year k, VIijk is the weekly/monthly/DOYs VI value for pixel i in week/month/DOY j for year k where by both the NDVI or EVI can utilized as VI, VIi, min and VIi,max are the multiyear minimum and maximum VI, respectively, for pixel i (UN-SPIDER. n.d.).



UN-SPIDER. n.d. “Recommended Practice: Drought monitoring using the Vegetation Condition Index (VCI).” United Nations Office for Outer Space Affairs UN-SPIDER Knowledge Portal. Accessed 09 28, 2021.

Related Content


Space technologies for drought monitoring and management

The impacts of climate change are ever more apparent. The frequency and scale of devastation and destruction of weather hazards are on an increasing trend. According to the latest Intergovernmental Panel on Climate Change Report (IPCC, 2021) climate change is intensifying the water cycle. This will cause more intense droughts in many regions. Moreover, water-related extremes impact the quality of life disproportionately strong. Drought accounts for 25% of all losses from weather-related disasters in the United States of America (Hayes et al., 2012).