论农业生产方式对两汉黄河下游水患的影响

Influences of Agricultural Production Modes on the Flood Scourges of the Lower Yellow River in Western Han and Eastern Han Dynasties

两汉时期黄河下游水患在次数和危害程度上均有较大差异。从农业生产方式上看,主要缘于两汉以山、陕峡谷流域和泾、渭、北洛河上游为主的黄河中游地区耕作方式和种植结构发生了变化:耕作方式方面,东汉时期这一地区牛耕区域较之西汉大幅缩减,利于水土保持;种植结构方面,东汉时期这一地区麦作面积增加和粟作面积减少,利于水土保持。此外,从作物种植场所选择上看,西汉时期黄河下游民众利用冬麦的防灾功效"缘堤垦殖",将冬麦扩植于河道及其滞洪区内,助长了黄河水患的发生;东汉王景治河后河道及滞洪区乱垦滥建的现象得到控制,有利于黄河相对安流局面的出现。

There were significant differences in both the number of times and degree of flood inthe downstream of the Yellow River in Western Han and Eastern Han Dynasties. From the way of agricultural production,the differences resulted from the change of tillage method and plantation structure in the middle reaches of the Yellow River which was based on canyons between Shanxi and Shaanxi,the upstream of Jinghe River,Weihe River and Beiluo River. In terms of tillage method,the sharp decrease of cattle farming area in the Eastern Han Dynasty was conductive to conservation of water and soil; in terms of plantation structure,the rise of wheat cultivation and the decline of millet was conductive to conservation of water and soil. Besides,from the choice of crop planting sites,people in the downstream of the Yellow River in Western Han Dynasty fomented the happening of flood in Yellow River by using the disaster prevention efficacy of winter wheat and planting winter wheat in the channel and flood retarding basin. The situation had been changed since Wang Jing harnessing the Yellow River in Eastern Han Dynasty,which was conductive to form a relatively stable complexion of the Yellow River.