Assessment of Drought in Democratic People’s Republic of Korea in 2017 Using TRMM Data

Drought is the main agrometeorological disaster in Democratic People’s Republic of Korea (DPRK), which has great influences on the growth of the crops and directly affects grain yield. Technologies of agricultural production level is low sciences of investment is little, and irrigation installation is poor in DPRK. Therefore, it is easy to cause a reduction in grain yield if drought occurs in DPRK. The Global Information and Early Warning System on Food and Agriculture (GIEWS) had proposed to warning food security of DPRK in 2017. Meanwhile, the food and Agriculture Organization (FAO) of the United Nations had also claimed that the rainfall in summer was insufficient and the grain yield would be reduction in DPRK. Hence, assessing the drought condition in DPRK is very important to understand the effects of drought on grain yield in 2017. In this study, the Tropical Rainfall Measuring Mission (TRMM)3B43 time series dataset from 1998 to 2017 was used to monitor the temporal and spatial characteristics of drought in DPRK in 2017. At national scale, the results show that the annual precipitation in 2017 was clearly lower than average precipitation during 1998 and 2017 in DPRK. Particularly, the annual precipitation was the lowest since 1998 in southern DPRK. A large number of studies show that Z-index can accurately assess the grade of drought. In this study, Z-index was applied for assessment the drought condition basis on TRMM data in 2017, which is used by the National Meteorological Center of China. The main agricultural regions were strongly affected by the drought in the study area, such as, in Hwanghaenam-do, Hwanghaebuk-do and Pyonganbuk-do. Furthermore, we assessed drought condition of crop growing season during March and September in 2017. According to Z-index, there was obvious drought in March, June and September in DPRK. The drought was severity in western DPRK in March. The magnitude of drought in Pyonganbuk-do was extreme drought and the Z-index value was -2.41 that was the lowest in 2017. Meanwhile, the magnitude of drought was severe drought in parts of Chagang-do and Pyongannam-do indicating obviously affected by drought. Moreover, 1.14 × 10⁵ km² (93.5%) area was affected by drought in June including Pyonganbuk-do, Pyongannam-do, Pyongyang City, Hwanghaebuk-do, Hwanghaenam-do and Hamgyungnam-do where showed magnitude of the drought is extreme drought. The maximum Z-index value was −1.95, that appeared in the Hwanghaenam-do. In addition, 75.3% of the study area appeared drought in September, especially eastern and central DPRK. The magnitude of drought was extreme drought in Gangwon-do. Totally, there were more than 2.0×10⁴ km² of croplands affected by drought in DPRK in 2017. The grain yield would be reduced due to drought occur during growing season in 2017. Thus, it is expected that the food gap would be appearance in 2018. Food aid should be provided by the international community in future.