Examining the Spatial-Temporal Evolution of the Chongzhen Drought (1627-1644) in China and Its Impact on Famine

Climate change is a critical context for the development of human civilization. Case studies on the societal impacts of climate change contribute to the understanding of the mechanisms of interactions between natural forces, ecosystems, and human societies. This study investigates the Chongzhen Drought occurring in 1627-1644 in China, which was very likely the worst drought in eastern China in the past 1500 years. Its duration, scope, and number of people affected are rare in history. At the same time, a large-scale famine broke out, which is argued as a main trigger of the peasant uprisings that led to the fall of the Ming Dynasty. This paper extracted 1,802 drought records and 1,977 famine records from Chinese historical documents (mainly local chronicles and history books) and reconstructed the spatio-temporal evolution of drought from 1627 to 1644 in eastern China as well as its impact on famine. First, we classified the drought events into four levels according to the duration and severity, based on the semantic differences. Then the kernel density estimation was used to reconstruct the spatial pattern of drought at annual resolution, as well as a series of Drought Kernel Density Index (DKDI) in different regions. The main drought area in 1627-1644 was located north of 29°N and shifted from Northwest China to North China and then expanded to the south. The development of drought in different regions was not synchronized. The DKDI series of North China approximated a single-peaked curve, with the drought gradually worsening from 1633-1640; the peak of DKDI in Northwest China also appeared in 1640. However, the DKDI series of the Yangtze-Huai Region showed a multi-peaked curve, constantly experiencing a cycle of drought aggravation-reduction in the early period and reaching its peak in 1641. Second, the spatio-temporal evolution of famine was also reconstructed and compared with drought. It showed that the range of drought and famine largely overlapped and their developing trends were generally similar.  However, the movement of the Famine Kernel Density Index (FKDI) series tended to be 1-2 years later than that of DKDI, suggesting a lag and continuation of transmission of drought impacts to the human system. Finally, the regression analysis showed that drought was the most critical factor triggering famine in this case with a contribution weight of 67.3%. The weight is higher at 73.4% in North China in comparison with other subnational regions. The study identified the transmission pathway from climate change to social consequences through “persistent drought → declining agricultural harvests → food shortage → famine”. While socioeconomic factors and human behaviours also played various roles in regulating the transmission process.