The Relationship of the Yellow River Flood and the Land Use in the Middle Reaches during the Han Dynasties
两汉时期黄河水患与中游土地利用之关系

According to the re-analysis on historical materials and combined w ith the modern scientific achievements on hydrology, physiognomy and soil erosi on, the author puts forth the new viewpoint on the environmental influence resu lting from the floods which occurred in the lower reaches and the land use styles in the middle reaches of the Yellow River. (1) Recordation in Hou Han Shu about most of the floods is simple and brief but it is more detailed about Yilo river floods. The river flooded several time s then and one of those even emerged some places of the Luoyang cit y. If the trunk stream of the Yellow River was flooded in, flooding mi ght also occur in the lower reaches. (2) During the 58 years from the river bu rsting in 11 AD till Wang Jing taming the River in 69 AD, there had been neither dam burst due to channel blockage nor harnessing practic es in the lower reaches. Flood deluged arbitrarily. It is obvious tha t there was no record in detail on flood because of omission on pur pose or with on intention. (3) Investigate the record about the flood in the Eastern Han Dynasty one year after another, the author found the frequency of flood in the Eastern Han Dynasty is higher than that in the Western Han Dynasty as well as the situation of the disaster. W ang Jing's river harnessment made the lower reaches stable for 36 year s rather than what was previously considered as 800 or 83 years. (4) T he population engaged in farming was reduced by more than 3/4 around the middle reaches of the Yellow River in the Eastern Han Dynasty. And a great deal of nomadic tribes immigrated in at that time, and their way of l ife by substantial damaging natural vegetation led to the aggravation of flood disaster of the lower Yellow River.