Monitoring Drought from Space and Food Security

Abstract

Drought is a typical phenomenon of the Earth’s climate. Losses from drought, especially in agriculture, are staggering. For example, in the USA, a country with the most advanced technology, the average annual drought damages are around $6 billion. In extreme drought years, such as 1988, costs jumped to $60 billion. Between 2001 and 2017, nearly 20% of land around the world was stricken by drought almost every year, and in some cases, that number is much higher. Developing countries in Africa and Asia were the most affected. During the first 17 years of the twenty-first century, the Horn of Africa experienced droughts 6 years in a row, which led to very serious food shortages and hunger. Mongolia’s rangelands suffered from very intensive droughts resulting in a lack of feed for livestock every 2–4 years. Unusual summer dryness also affected main grain-producing countries of the Black and Caspian Seas regions in 2007, 2009, 2010, 2012, and 2013. Weather data is traditionally used for drought monitoring. However, a weather-derived drought-watch system has a few serious shortcomings. Weather data represents point locations rather than an area and the number of meteorological stations around the globe are quite limited and not distributed evenly, especially in African countries, which have frequent problems with food security. Even in the United States, with a well-developed weather network, the density of stations is not sufficient for efficient drought monitoring. The US Drought Monitor (USDM), assumed by some users as an official US drought system, provides drought information for an area of 1,500,000–2,000,000 million acres of US territory, while California, producing nearly 90% of the USA’s vegetables, fruits, berries, and nuts, needs this information for each 200–500 acres occupied by each crop in the primary, irrigated Central Valley. This chapter discusses how the new vegetation health (VH) technology uses high-resolution (0.5 and 1 km2) and mid-resolution (4 and 16 km2) 38-year NOAA operational polar-orbiting satellite data (SNPP/VIIRS, NOAA-20/VIIRS and NOAA/AVHRR) for early drought detection, monitoring its features (area, intensity, duration, origination, impacts, etc.) and prediction of agricultural losses, which is used for global and regional food security assessments.