Process, spatial pattern and impacts of 1743 Extreme heat: From the perspective of historical documents

Abstract. The study of historical extreme heat is helpful to understand modern heat waves. By collecting 63 historical documents from 3 kinds of historical materials and using methods of text analysis methods based on keywords, grading and classification, this research recovered and analyzed the process over time, the spatial pattern of the heat severity and the extreme heat impact of the North China extreme heat in 1743. The results show: 1) The extreme heat of 1743 began to noticed by people on June 22, began to kill people on July 14, and was most severe and attracted great attention from the central government between July 14 and 25. 2) The extreme heat occurred in the plains north of the Yellow River and in the valleys of southwestern Shanxi. Areas in the plains east of the Taihang Mountains such as Baoding, Shijiazhuang, and Xingtai suffered worst heat. They are also at high risk for heat waves in the North China Plain in modern times. 3) In 1743, the heat affected people, animals, plants and facilities, with the most severe impact of human deaths. The death toll in a single county reached dozens in a single day. Timely cooling and reducing exposure are limited but necessary means to deal with high temperatures in both ancient and modern times.