Downstream Channel Evolution and Its Causes in the Yuan River during the Qing Dynasty.

The determination of channel evolutions and the causes is important for reconstructing the evolutionary history of river landforms. This study aimed to elucidate the downstream channel evolution of the Yuan River in Hunan Province, China, during the Qing Dynasty via Landsat 8 satellite image data and relevant literature. The objective was to establish the modes of channel evolution and discuss the significance of historical climate change. The downstream paleochannel of the Yuan River was identified in the Late Ming Dynasty and Early Qing Dynasty (1600–1644 AD), the Kangxi-Qianlong periods of the Qing Dynasty (1661–1796 AD), the Late Qing Dynasty (1840–1912 AD), and the World War II (1939–1945 AD), and three main modes of river evolution were determined. Using remote sensing data and the ancient literature, the evolution characteristics of the paleochannel in the Lower Yuan River were analyzed and its distribution across historical periods was comprehensively revealed. The findings reveal a strong correlation between channel evolution, flood events, and climate change. Numerous flood events that occurred from the Late Qing Dynasty to the World War II caused a high rate of channel evolution, demonstrating the combined effects of climate change and human activities. These findings will help adopt robust and resilient hydrological management methods in the future of a changing climate. [ABSTRACT FROM AUTHOR]