SNPP/VIIRS vegetation health to assess 500 California drought

Abstract

Beginning in 2006, western United States was affected by a 11-year strong mega-drought. Among 17 western states, California was the most severely drought-affected during 2012–2015, when an area of stronger than moderate vegetation stress reached 70%. This drought had considerable impact on California's environment, economy and society. Currently, drought in the USA is monitored by the US Drought Monitor (USDM), which estimates drought area and intensity on a large area (nearly 1000 km2). California produces more than 90% of US's fruits, vegetables, berries and nuts, which are grown on relatively small areas (200–500 acres, or 0.5–2 km2). Since most of these crops are irrigated, it is important to estimate crop conditions on the area comparable to the size of the planted crop. This paper demonstrates how the new 500-m vegetation health (VH) technology (VH-500), developed from data collected by the SNPP/VIIRS satellite launched in 2011, monitors this mega-drought in California, distinguishing drought-affected area with and without irrigation and estimating drought start/end, intensity, duration, impacts and recovery from 2015–2016 El Niño.