Water level change of Lake Machang in eastern China over 1814–1902 CE

Lake Machang, occupying an area of approximately 30 km2 in the city of Jining, eastern China, was a historical reservoir on the Grand Canal from the early 15th century to early 20th century. The premodern monthly water level observation of Lake Machang commenced in 1814 CE and ended in 1902 CE. The available observation data from the monthly records covered 75.6 % of the entire study period of 1814–1902. Although the water level was seemingly artificially influenced by human activities, monthly and annual water level changes still correlated well with precipitation. That is, climate is still the dominant factor in water level changes on seasonal and annual scales. The flooding of the Yellow River in 1871 carried a large amount of silt into Lake Machang, which resulted in the rise of the lake bed and reclamation initiated by local residents. After the reclamation activity was officially approved in 1900, Lake Machang was massively reclaimed and eventually dried up in the early 20th century.