- Useful for international support and countermeasures for droughts-
In the global agricultural production, drought is said to be the one of the largest weather-related disaster. NARO has clarified the geographical distribution of global crop production losses caused by droughts. Analysis of drought index and crop yield data for the past 27 years (1983-2009), reveals that three quarters (450 million hectares) of the cultivated area of the major global crops (maize, rice, soy, wheat) have been affected by droughts. The total production losses over the past 27 years which is estimated from the crop production losses obtained this time and the producer price by country (2005), has reached about $166 billion. This research achievement is useful for international support and measures against droughts.
The frequency of occurrence of climate extremes associated with the climate change is increasing, hence there is concern about its adverse effect on global crop production. Among the climate extremes, the adverse effect caused by droughts on global crop production is said to be largest. However, the detailed geographical distribution about the impact of global crop production due to droughts was unknown. Therefore, NARO analyzed drought index and crop yield data, and for the first time in the world, they clarified the geographical distribution of impact of global crop production due to droughts, with high resolution of 50km mesh.
The cultivation area of crops that has suffered yield loss from one or more droughts in the last 27 years (1983-2009) was, 161 million hectares of wheat (75% of the world's harvested area), 124 million hectares of maize (82%), 102 million hectares of rice (62%) and 0.67 billion hectares of soy (91%). In addition, the crop yield reduction rate due to one drought in an average of 27 years was 8% for wheat (0.29 tons per hectare), 7% for maize (0.24 tons -same), 3% for rice (0.13 tons-same), 7% for soy (0.15 tons-same).
This achievement makes it possible to grasp the situation of crop production losses due to the past droughts and to estimate the amount of losses in the future. Hence it will be useful for the international support and measures against the droughts and for stable import and supply of Japanese crops.
The research results were published in the Journal of the American Meteorological Society "Journal of Applied Meteorology and Climatology" .
Wonsik Kim, Toshichika Iizumi, Motoki Nishimori (2019) Global patterns of crop production losses associated with droughts from 1983 to 2009. Journal of Applied Meteorology and Climatology https://doi.org/10.1175/JAMC-D-18-0174.1
Fig.1 Global patterns of average drought-induced yield loss per drought event from 1983 to 2009 (Kim et al. 2019 in Journal of Applied Meteorology and Climatology).
Fig.2 Relationships between the per capita GDP and the average drought-induced yield loss produced by individual drought events from 1983 to 2009 (Kim et al. 2019 in Journal of Applied Meteorology and Climatology).