River system changes and locust breeding area evolution in the Qin-Jin region of the Yellow River Basin during the Ming and Qing dynasties and their disaster effects.

Based on the locust outbreak records in historical documents, we extracted 654 locust outbreak events in the Qin-Jin region of the Yellow River Basin during the Ming and Qing dynasties (1368-1911 CE), reconstructed the locust disaster index series according to the severity of locust plagues, and compared them with the flood, drought, famine and river disasters in the same period. The objective was to investigate the process of river system changes in the Qin-Jin region of the Yellow River Basin, their relationship with the evolution of the locust breeding area and disaster effects. The results indicate that locust outbreaks in the Qin-Jin region of the Yellow River basin during the Ming and Qing dynasties were concentrated in the summer and autumn, with disaster grades 2 and 3 predominating. The interannual series of locust outbreaks showed "one peak (1644-1650 CE) and four mounds (1527-1537 CE, 1613-1620 CE, 1690-1704 CE, and 1854-1864 CE)". On the 10-year scale, locust outbreaks were positively correlated with famine and moderately associated with drought and river clearing. The spatial distribution of locust-prone areas corresponded well with drought and famine. The locust breeding areas in the Qin-Jin region were dominated by river flooding locust breeding areas, where topographic factors and river changes more influenced locust distribution. The DPSIR model revealed that potential climatic, locust, and demographic "drivers" exerted "pressure" on the Qin-Jin region of the Yellow River Basin, causing changes in the social, economic and environmental "state" of the locust-prone areas, which in turn "impact" people's livelihoods and ultimately led to a series of central-local-populace "responses".