Agricultural drought hazard analysis during 1980-2008: a global perspective

Various studies have been performed on drought hazard assessment at the national or regional scales, but few studies to date at the global scale, especially on global agriculture. In this paper, we utilized an agricultural drought hazard index (DHI), based on both drought severity and drought occurrence rate, derived from 3-month scale Standardized Precipitation Index (SPI) and the phenology data of main crops (rice, maize, wheat, barley, sorghum and soybean) to assess the agricultural drought hazard grades of the world during 1980-2008. The results indicated that area percentages of high and very high agricultural drought hazard zones were approximately 23.57 and 27.19% of the total agricultural area in the world. Moreover, those zones mostly were distributed in central United States, southeastern South America, most of Europe, southwestern Russia, both southern Congo and Nigeria, east-central and southwest China, Southeast Asia and eastern Australia, and most of those areas were also located in semi-humid or humid climate zones. In addition, some regions above were also found to be the very high agricultural drought hazard zones for the main crops: East-central and southwest China for wheat, maize, rice and soybean; Europe for wheat, maize and barley; Southeast Asia for rice; both central United States and southeastern South America for wheat, maize, soybean and sorghum.