Water level change of Lake Machang in eastern China during the past 200 years

Abstract. Lake Machang, which occupies an area of approximately 30 km2 in Jining City of eastern China, was a historical reservoir on the Grand Canal existing from early 15th century to early 20th century. The premodern monthly water level observation of Lake Machang commenced in 1814 AD and ended in 1902 AD. The available observation data from the monthly records could cover 75.6 % of the whole study period 1814–1912. Although the water level was seemingly artificially intervened by human activities, monthly and annual water level changes still correlated well with precipitation. That is, climate is still the dominant factor of water level changes on seasonal and annual scales. The flooding of the Yellow River in 1871 AD carried large amount of silt into Lake Machang, which resulted in the rise of lake bed and reclamation initiated by local residents. In particular, after the reclamation activity was officially approved in 1900 AD, Lake Machang was massively reclaimed and eventually dried up in the early 20th century.