Spatial-temporal pattern of drought hazards in China's Qing dynasty based on forbidden city archives

The study of spatial-temporal pattern of drought hazards has attached great importance to government and academia in China under a changing climate. The spatial-temporal pattern of drought hazards in China for the period 1689-1991 is reconstructed using the data extracted from the drought hazard document archived in the Forbidden City during the Qing dynasty, and the geographic information system (GIS) technique. The result shows that ① the areal extent of drought fluctuated three times with time during the study period, and a total of 9 typical drought years were identifiable from the reconstructed data; ② spatially, three drought-prone regions were found. These regions were in northwest China covering the Gansu province and the Ningxia-Hui Autonomous Region, in north China including the provinces of Shandong, Hebei and Henan as well as Tianjin Municipality, and in the Jianghuai area of Anhui and Jiangsu provinces; ③ seasonally, summer droughts were dominant during the Qing dynasty. The reconstructed spatial-temporal pattern of drought hazards based-on Forbidden City archives is in line with the historical facts during the Qing dynasty.