The sequence of twelve woodblock maps presented here from the mid-nineteenth-century gazetteer for the department of Dengchuan in southwest China shows the Miju river and the irrigation system that lay at the heart of its farming economy. The incorporation into the cartography of much of the administrative detail related to the compulsory mobilization of labour for the annual clearance of mud makes it unusual among Chinese maps depicting water control in this period. The clarity with which it shows the recent formation of a long, spit-like delta of deposited sediment protruding into the Erhai, the large mountain lake into which the river empties, also assists the dating and analysis of the environmental crisis that occasioned it. During the late seventeenth century, and much of the eighteenth, the pressure of population caused the opening for cultivation of the unstable mountain soils on the slopes of the catchment just upstream of the section depicted by the maps. The result was a massive increase in the river’s load of sediment. The dykes of its downstream bed rose to a level above the surrounding farmland. The increased need for maintenance led to the restructuring of parts of the system of government, and the lives of the local people, so as to handle the new problems. We have found that the accuracy of the maps was adequate for planning and executing middle-sized water control projects at the technical level of that time.
- National Library of Australia
- Yunnan Province, China
- Dengchuan county gazetteer
- 19th century ideographs