||Secular Change and Regional Features of Climatic Disasters during 7th -12th centuries
MARUMOTO, MikiFUKUOKA, Yoshitaka
JAPANESE PROGRESS IN CLIMATOLOGY
26 , 2015-12 , JAPAN CLIMATOLOGY SEMINAR
Many natural disasters had occurred in Japan during the second half of the 9th century. It corresponds to the "Medieval climate anomaly (MCA)" or "Medieval warm period (MWP)" existed from 9th to 12th centuries pointed out by the climatology in Europe and U.S.A. In the history of Japan, however, this period is called "ancient period". In this study, the authors reconstruct a chronology of climatic disasters based on 1,220 cases from 7th to 12th centuries that were obtained by historical documents and clarify according to their kinds and areas. It can be said that numbers of climatic disasters increase in the period with increasing temperature. Especially that is remarkable during the second half of 9th century and the early 10th century. On the kinds of climatic disasters, the most common disaster is storm (26.1%) and the next is drought (19.8%). As for place names related to all climatic disasters, most frequency is Kyoto (48.3%) and second is Nara (7.9%). From these results, before the 9th century, droughts in Nara were the major climatic disasters. On the other hand, descriptions of disasters caused by too much rain as heavy rains and long rains in Kyoto were found from the 9th century.